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Abstract We present a comprehensive analysis of the semileptonic weak decays of $$B_c$$ B c meson decaying to axial-vector (A) mesons for bottom-conserving and bottom-changing decay modes. We employ self-consistent covariant light-front quark model (CLF QM) that uses type-II correspondence to eliminate inconsistencies in the traditional type-I CLF QM. As a fresh attempt, we test the self-consistency in CLF QM through type-II correspondence for $$B_c \rightarrow A$$ B c → A meson transition form factors. We establish that in type-II correspondence the form factors for longitudinal and transverse polarization states are numerically equal and are free from zero-mode contributions, which confirms the self-consistency of type-II correspondence for $$B_c \rightarrow A$$ B c → A transition form factors. Furthermore, we ascertain that the problems of inconsistency and violation of covariance of CLF QM within the type-I correspondence are resolved in type-II correspondence for $$B_c \rightarrow A$$ B c → A transitions. We thoroughly investigate the effects of self-consistency between type-I and type-II schemes using a comparative analysis. In this investigation, we employ a direct calculation approach to determine the form factors within the space-like region. Subsequently, we employ a vector meson dominance (VMD)-inspired three-parameter form to extrapolate these form factors into the physically accessible region. This enables us to study the $$q^2$$ q 2 dependence of the form factors in weak hadronic currents for the whole accessible kinematic range for both bottom-conserving as well as bottom-changing transitions. In addition, we extend our analysis to predict the branching ratios of the semileptonic weak decays of $$B_c$$ B c meson involving axial-vector meson in the final state to quantify the effects of self-consistency in these decays that were not studied before. We evaluate the lepton mass effect on these branching ratios and various other important physical observables, such as forward-backward asymmetries, lepton-side convexity parameter, asymmetry parameter, and longitudinal polarization asymmetries and fractions. Finally, we obtain the lepton flavor universality ratios for various decays.

Abstract Electrochemical research often requires stringent combinations of experimental parameters that are demanding to manually locate. Recent advances in automated instrumentation and machine-learning algorithms unlock the possibility for accelerated studies of electrochemical fundamentals via high-throughput, online decision-making. Here we report an autonomous electrochemical platform that implements an adaptive, closed-loop workflow for mechanistic investigation of molecular electrochemistry. As a proof-of-concept, this platform autonomously identifies and investigates an EC mechanism, an interfacial electron transfer (E step) followed by a solution reaction (C step), for cobalt tetraphenylporphyrin exposed to a library of organohalide electrophiles. The generally applicable workflow accurately discerns the EC mechanism’s presence amid negative controls and outliers, adaptively designs desired experimental conditions, and quantitatively extracts kinetic information of the C step spanning over 7 orders of magnitude, from which mechanistic insights into oxidative addition pathways are gained. This work opens opportunities for autonomous mechanistic discoveries in self-driving electrochemistry laboratories without manual intervention.

Background: Pituitary Adenoma, a neoplastic proliferation of anterior pituitary hormone producing cells, is mainly considered benign but some are clinically aggressive and recurrent and very rarely malignant. From recent advances in pathological and molecular study, there is a continuous search for numerous prognostic biomarkers, to analyze better tumor behavior and prediction of response to treatment and recurrences. This study was conducted to see the epidemiological spectrum of pituitary tumors and to evaluate the correlation of TOPOISOMERASE IIα (Topo 2A), and Ki-67 biomarker with recurrence, aggressiveness, hormone subtype, radiological invasiveness, and prognostic grade of pituitary tumors. Materials and methods:This was a prospective study with a total of 54 cases. We studied the clinical behavior, radiology, histopathological findings, and immunohistochemistry with Ki-67, Topoisomerase IIα, over 3 years at a tertiary care center. Results:When comparing Ki-67 expression with aggressiveness, a high degree of statistical significance was found (Mann -Whitney U Test, p-value

Introduction The effects of COVID-19 infection persist beyond the active phase. Comprehensive description and analysis of the post COVID sequelae in various population groups are critical to minimise the long-term morbidity and mortality associated with COVID-19. This analysis was conducted with an objective to estimate the frequency of post COVID sequelae and subsequently, design a framework for holistic management of post COVID morbidities.Methods Follow-up data collected as part of a registry-based observational study in 31 hospitals across India since September 2020–October 2022 were used for analysis. All consenting hospitalised patients with COVID-19 are telephonically followed up for up to 1 year post-discharge, using a prestructured form focused on symptom reporting.Results Dyspnoea, fatigue and mental health issues were reported among 18.6%, 10.5% and 9.3% of the 8042 participants at first follow-up of 30–60 days post-discharge, respectively, which reduced to 11.9%, 6.6% and 9%, respectively, at 1-year follow-up in 2192 participants. Patients who died within 90 days post-discharge were significantly older (adjusted OR (aOR): 1.02, 95% CI: 1.01, 1.03), with at least one comorbidity (aOR: 1.76, 95% CI: 1.31, 2.35), and a higher proportion had required intensive care unit admission during the initial hospitalisation due to COVID-19 (aOR: 1.49, 95% CI: 1.08, 2.06) and were discharged at WHO ordinal scale 6–7 (aOR: 49.13 95% CI: 25.43, 94.92). Anti-SARS-CoV-2 vaccination (at least one dose) was protective against such post-discharge mortality (aOR: 0.19, 95% CI: 0.01, 0.03).Conclusion Hospitalised patients with COVID-19 experience a variety of long-term sequelae after discharge from hospitals which persists although in reduced proportions until 12 months post-discharge. Developing a holistic management framework with engagement of care outreach workers as well as teleconsultation is a way forward in effective management of post COVID morbidities as well as reducing mortality.

Introduction: There is a lack of Indian data on short stature treatment using recombinant human growth hormone (rhGH). We explored the effects of such treatment in eastern Indian patients, with emphasis on biochemical parameters and bone biomarkers in addition to basic anthropometry. Methods: Our descriptive study covered 50 short stature patients of varied aetiology attending endocrine outpatient department (OPD) of a tertiary care teaching hospital. Patients were followed up for 1 year after the index visit, and prospective data were reconciled with past medical records. A dose of rhGH used was 0.18–0.375 mg/kg as standard, starting dose mostly being 0.2 mg/kg. Dosing was adjusted if the physician judged the clinical outcome to be less favourable than expected. Anthropometric parameters (height, weight, body mass index (BMI) and skeletal age) were recorded clinically, and various biochemical parameters and bone biomarkers were estimated from blood. Results: Among 50 subjects, 60% had idiopathic growth hormone (GH) deficiency and 26% had Turner's syndrome. The median age at treatment start was 10 years, and the median treatment duration was 25.5 months. The height increased more in the first year of therapy. In the last 6 months, the height velocity was approximately 0.5 cm/month. Although the weight increased significantly, the increment slowed down in the last 6 months. Both remained less than age- and gender-matched references throughout. The skeletal age was on average 2 years behind chronological age (CA)—being 8.7, 9.6 and 11.3 years, respectively, at therapy start, after one year and at study end. Fasting blood glucose (FBG), total cholesterol and calcium level changes were not statistically significant. Serum cortisol and phosphate showed a modest but statistically significant rise, while thyroid-stimulating hormone (TSH) level declined. Insulin-like growth factor 1 (IGF-1) increase was relatively pronounced. Among bone biomarkers, a decrease in CTx and an increase in vitamin D were significant. Dual-energy X-ray absorptiometry (DEXA) data indicated that bone mineral density was less than that of age-matched controls despite treatment. The therapy was well tolerated. Conclusions: rhGH treatment leads to significant improvement in anthropometry in Indian children comparable with Western data. Bone biomarker changes indicate decreased bone resorption and increased bone formation although bone mineral density still lags behind age-matched controls.

Abstract Background Increased occurrence of mucormycosis during the second wave of COVID-19 pandemic in early 2021 in India prompted us to undertake a multi-site case–control investigation. The objectives were to examine the monthly trend of COVID-19 Associated Mucormycosis (CAM) cases among in-patients and to identify factors associated with development of CAM. Methods Eleven study sites were involved across India; archived records since 1st January 2021 till 30th September 2021 were used for trend analysis. The cases and controls were enrolled during 15th June 2021 to 30th September 2021. Data were collected using a semi-structured questionnaire. Among 1211 enrolled participants, 336 were CAM cases and 875 were COVID-19 positive non-mucormycosis controls. Results CAM-case admissions reached their peak in May 2021 like a satellite epidemic after a month of in-patient admission peak recorded due to COVID-19. The odds of developing CAM increased with the history of working in a dusty environment (adjusted odds ratio; aOR 3.24, 95% CI 1.34, 7.82), diabetes mellitus (aOR: 31.83, 95% CI 13.96, 72.63), longer duration of hospital stay (aOR: 1.06, 95% CI 1.02, 1.11) and use of methylprednisolone (aOR: 2.71, 95% CI 1.37, 5.37) following adjustment for age, gender, occupation, education, type of houses used for living, requirement of ventilatory support and route of steroid administration. Higher proportion of CAM cases required supplemental oxygen compared to the controls; use of non-rebreather mask (NRBM) was associated as a protective factor against mucormycosis compared to face masks (aOR: 0.18, 95% CI 0.08, 0.41). Genomic sequencing of archived respiratory samples revealed similar occurrences of Delta and Delta derivates of SARS-CoV-2 infection in both cases and controls. Conclusions Appropriate management of hyperglycemia, judicious use of steroids and use of NRBM during oxygen supplementation among COVID-19 patients have the potential to reduce the risk of occurrence of mucormycosis. Avoiding exposure to dusty environment would add to such prevention efforts.

Introduction: Perineural dexamethasone gives promising results in prolonging duration of analgesia in brachial plexus block. Doses between 1 to 10 mg have been used but the optimum dose is not yet settled. Aim: To compare the analgesic efficacy of two low doses of dexamethasone in Ultrasonography (USG)-guided brachial plexus block for planned upper limb surgery. Materials and Methods: A double-blind randomised clinical trial was conducted with 126 adult patients of either sex, randomised in equal numbers to 2 mg and 4 mg dexamethasone groups, the steroid being administered in conjunction with 0.5% levobupivacaine. Time to onset of sensory and motor blocks, duration of analgesia, duration of motor block, total consumption of analgesics in the first 24 hours postoperative period, haemodynamic parameters and features of neurotoxicity were compared. Tramadol 50mg intravenous was permitted as rescue analgesic. Results: No significant differences in onset of sensory and motor blocks were encountered. Duration of sensory block with 4 mg {median (Interquartile range); 1080 (900-1140) min} clearly exceeded that with 2 mg {840 (720-960) min} (p-value

Objective: The objective of this study is to delineate the characteristics and outcome of Pediatric Inflammatory Multisystem Syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARSCoV2) infection (PIMS-TS) in Eastern Indian settings. Materials and Methods: We conducted a prospective observational multicentric study from May 2020 to August 2020, collecting data on clinical profile, investigation findings, and outcome of the children aged 1 month–12 years admitted with the features of coronavirus disease 2019 (COVID-19) related hyperinflammation satisfying criteria for PIMS-TS from three tertiary care hospitals of Kolkata. Results: A total of 38 patients fulfilling the criteria of PIMS-TS were recruited. The median age of the study population was 5 years (1.9–8 years). Gastrointestinal symptoms were present in 33 (86.6%) of patients. Nasopharyngeal swab for COVID-19 reverse transcriptase-polymerase chain reaction was positive in 19 (50%) of patients, and immunoglobulin G antibody against COVID-19 was found in 12 (66.6%) of patients, whereas 19 (50%) of patients had a positive contact history of SARS-Co-V2 exposure. The features of Kawasaki, like illness with coronary changes, were seen in 12 (32%) cases, whereas myocarditis with ejection fraction

Purpose: This multicentric questionnaire-based study was undertaken to address the lack of systematic background data on the knowledge, attitudes, and practices among Indian physicians related to antimicrobial use and resistance. Materials and Methods: A validated structured study questionnaire was used for capturing respondent particulars, antimicrobial prescribing habits, knowledge of antimicrobial resistance (AMR), ways of choosing and learning about antibiotics, agreement or disagreement with certain perceptions regarding antibiotics, selection of antibiotics in specific settings, and suggestions regarding rationalizing antimicrobial use in the practice setting. Summary statistical analysis of the pooled data was done. Results: Five hundred and six respondents with a mean (standard deviation) age of 31.4 (8.71) years participated in the study. Three hundred and twenty-seven were medical and 179 surgical discipline clinicians. Overall, the theoretical knowledge about antimicrobials was satisfactory, but areas of concern were noted in the attitude and practice domains. A substantial proportion of participants failed to identify the correct choice of antibiotics in the case-based scenarios. 38.33% reported not attending a single continuing medical education on antimicrobials during the past year. Statistically significant differences were not observed in the KAP quotient scores between medical and surgical discipline respondents. Conclusions: Despite satisfactory background knowledge regarding the rational use of antimicrobials and AMR patterns, there are discrepancies in the physicians' prescribing attitude and thus strengthen the case for instituting specific interventions to improve antimicrobial prescribing.

Introduction: The studies in animal models of cirrhosis suggest that dipeptidyl peptidase type 4 (DPP-4) enzymes play a crucial role in disease pathogenesis. In this clinical observational study, activity of DPP-4 and related gene expression were analysed in chronic liver disease patients. Objectives: To understand the DPP-4 enzyme activity variation in the common types of chronic liver disease by assessing plasma and peripheral blood mononuclear cell (PBMC) DPP-4 activity and comparing with healthy controls and to explore DPP-4 gene expression in PBMC. Methods: We recruited 130 study subjects in four cohorts—46 nonalcoholic fatty liver disease (NAFLD), 23 non-alcoholic cirrhosis (NAC) excluding viral aetiology, 21 alcoholic liver disease (ALC), and 40 control subjects. Blood samples were analysed for relevant biochemical parameters and plasma DPP-4 activity. PBMC fraction was used for the DPP-4 activity assay and gene expression analysis. Results: We found that lower plasma DPP-4 activity among patient cohorts but this was not statistically significant. The PBMC DPP-4 activity was significantly lower in NAFLD cohort. In the same cohort, DPP-4 gene expression in PBMC fraction was significantly increased (P < 0.05). There was significant correlation between plasma DPP-4 activity and liver injury marker alanine aminotransferase (ALT) among NAFLD (rho = 0.459, P < 0.01), NAC (rho = 0.475, P < 0.05), and ALC (rho = –0.572, P < 0.01) patients. Plasma DPP-4 activity modestly predicted ALT plasma level (beta coefficient = 0.489, P < 0.01). Conclusions: The PBMC DPP-4 activity and DPP-4 gene expression gets significantly altered in NAFLD patients. Plasma DPP-4 activity also shows correlation with ALT levels in CLD patients. The role of DPP-4 in disease pathology in NAFLD and other forms of CLD needs to be explored.

Objective There is no established diagnostic test available to diagnose neonatal sepsis. Tumor necrosis factor a (TNFα), interleukin 1b (IL1β) and interleukin 6 (IL6) showed some promising results in some recent studies in this respect, but their roles in diagnosis and prognosis of neonatal sepsis are not yet conclusive. In this study, we have tried to identify diagnostic and prognostic ability of these biomarkers in neonatal sepsis. Methods In this cross-sectional study, blood sample for 3 cytokines were collected at diagnosis of neonatal sepsis fulfilling diagnostic criteria by purposive sampling and values were compared with normal healthy newborns. Each of the cytokines was evaluated separately to identify, whether they can detect neonatal sepsis with at least 70% sensitivity and specificity. At the same time, their prognostic values were also evaluated in terms of disease severity and mortality. Results Among twenty normal newborns, standard deviation values of TNFα, IL1β and IL6 were 39.7±21.5 pg/ml, 34.6±20.9 pg/ml and 44.4±33.0 pg/ml, respectively. In sepsis group (n=40), these values were 69.6±26.0 pg/ml, 57.7±29.0 pg/ml and 204.6±169.2 pg/ml, respectively. All these differences were statistically significant (p

Abstract Introduction: Sonneratia apetala Buch-Ham is a true mangrove inhabitant in Indian Sunderban and it is used in folk medicine for digestive disorders. Method: Hydro-methanolic (20:80) extract of Sonneratia apetala leaves (SA) was chemically standardized by HPTLC and evaluated for its antiradical and gastro-protective properties. Phenolics and flavonoids present in SA were determined and antiradical activities were assessed by in vitro methods like, DPPH (1,1-diphenyl-2-picrylhydrazyl), nitric oxides, superoxides, hydroxyl and ABTS (2,2/-azino-bis-3-ethyl benzthiazoline-6-sulphonic acid). Further, gastro-protective efficacy of SA was assessed in alcohol (50% v/v, 5 ml/kg) induced oxidative ulceration in rats. Results: Chemically standardized SA exhibited presence of polyphenolic compounds. It also showed strong antiradical properties. Oral administrations of SA (125 mg/kg and 250 mg/kg) significantly protected gastric mucosal membrane from ulcerative damage caused by alcohol, similar to Omeprazole (20 mg/kg) in rats. Moreover, SA treatment significantly reduced the elevation of lipid peroxides; while enhanced the concentration of glutathione and catalase in gastric mucosa in respect to ethanol induced untreated control rats. Conclusions The results obtained from this study suggest Sonneratia apetala leaf has antioxidant properties and has capabilities to protect gastric mucosal injury caused by alcohol ingestion.

Objectives: Package inserts (PIs) are used by physicians and other health-care providers as ready source of approved prescribing information. In India, they are subject to statutory regulations that specify the information to be provided under various headings. Uniformity of PIs with optimal level of information is desirable, the absence of which may lead to medication errors. This observational study aimed to evaluate the information adequacy and accuracy of PIs available in the Indian market. Materials and Methods: PIs of drugs marketed in India, and approved by United States Food and Drug Administration, were collected from various retail pharmacies through purposive sampling. The adequacy and accuracy of the information in each PI were evaluated with the help of a 25-item checklist prepared as per stipulations mentioned in statutory guidelines. Each required item of information was scored 1 if present and appropriate or 0 if absent or deemed incomplete or inaccurate. A total information adequacy score (IAS), with maximum value 25, was thereby calculated. Results: From the total 135 PIs analyzed, the median IAS was 17 (interquartile range 15–19). Deficiencies were observed under important headings. For example, “references” were mentioned in only 6.67% and “date of last updating” in only 19.26% of PIs. Other notable shortcomings were in “disposal” (not mentioned in 92.59%), “effects on ability to drive and use machines” (76.30%), “pharmaceutical incompatibilities” (66.67%), “shelf life” (62.96%), “excipients” (60.00%), and “overdose” (17.78%) information. Information on “generic name,” “composition,” and “indications” were however provided by all (100%) PIs. Conclusions: The information provided by PIs in India being inadequate, may not be able to serve as a reliable source of information.

Background: Transporting sick neonates from the periphery to a tertiary care unit is a challenge and transport-related factors can have a bearing on their survival. These factors influence ultimate survival in resource poor settings. Objectives: The objective is to evaluate the transport characteristics for sick newborns from peripheral centers to tertiary care referral hospital. Methods: A prospective study was done with sick newborns transported to our tertiary care teaching hospital over a period of 1 year. The transport logistics were recorded in detail and analyzed. The analyses were repeated for preterm and term babies separately. Results: There were 36.32% preterm babies in the study cohort of 961 newborns. The descriptive profile of the newborns enrolled in the study has been presented along with descriptive summary of the newborn transport logistics. Approximately 23% of babies were born to teen age mothers. Some prereferral counseling was done for only about 20% babies and

IntroductionMoyamoya angiopathy (MMA) is a chronic, progressive intracranial vasculopathy with variation in prevalence and clinical manifestations across different populations. This study was aimed to estimate the frequency of MMA as an etiology of stroke and its epidemiological features in the largest cohort of MMA patients in India.MethodA single-centered cross-sectional observational study over a period of 5 years (2016–2021) was undertaken among consecutive stroke and transient ischemic attack (TIA) patients to look for the presence of MMA angiographically. Each patient with angiographically proven MMA was further evaluated for demographic, clinical, and radiological characteristics.ResultsAmong 10,250 consecutive stroke and TIA patients (ischemic = 78%, hemorrhagic = 22%), frequency of MMA was 1.56% (n = 160); 15.3% among children. Female preponderance (Male:Female = 1:1.4) was noted among 160 MMA patients, with bimodal age distribution, first peak at 3–8 years, and a shorter second peak at 41–47 years. Childhood-onset MMA was seen in 75 (46.9%) with commonest initial neurological symptom of fixed-motor-weakness (44.0%), followed by TIA (26.7%); while 85 (53.1%) had adult-onset MMA with fixed-motor-weakness (50.6%) followed by headache (24.7%) as the predominant initial neurological symptom; seizure significantly higher in children (p < 0.001) and headache in adults (p = 0.012). Transient and fixed neurological manifestations constituted 87.5 and 69.4% respectively, of symptoms throughout the disease course. Cerebral infarction (45.0%) and TIA (21.9%) were the commonest types of MMA. On brain imaging, infarction was noted in 80.6%, hemorrhage in 11.3%, significantly higher among adults (p < 0.001). Cortical infarct and Gyral pattern were commoner in children (p = 0.004), subcortical infarcts in adults (p = 0.018). Frequent Suzuki staging observed was stage 4 (31.3%), followed by stage 3 (30.0%). Involvement of posterior circulation was detected in 55.6%, brain atrophy at the time of diagnosis was seen in 65.0%.ConclusionMMA is an important etiological consideration in patients with stroke, especially in children. It can present with a myriad of transient neurological symptoms, frequently overlooked, leading to delayed diagnosis, and contributing to socio-economic burden. Indian MMA showed aberrations in its gender predisposition, age distribution, frequency of familial cases, disease manifestation, and type of stroke, in comparison to its Japanese and Caucasian counterparts pointing to the inter- and intra-continent differences of MMA phenotype. Future development of the Indian MMA national registry is of essence.

Aim: Poisoning is a preventable cause of morbidity and mortality in India. We undertook a prospective observational study to estimate the incidence, nature, severity and treatment outcome trends of acute poisoning in a tertiary care hospital in eastern India. Methods: All patients, admitted during the study period with acute poisoning, drug overdose and envenomation, were enrolled. Food poisonings, animal bites, chronic drug or chemical poisonings were excluded. Medical records were scrutinized and caregiver interviews served as source documents. Demographics, nature and circumstances of the poisoning event, treatment offered, duration of hospitalization and outcome data were collected. Results: Over 18 months, 592 cases of acute poisoning, accounting for 0.63% of all hospital admissions, were enrolled. Males comprised 57.09%, median age was 22 years, and 52.20% hailed from rural area. Occupation-wise, excluding students and children, patients were mostly daily wage workers followed by housewives, service holders and farm workers. Snake bites comprised the largest category of cases at 264 (44.6%) followed by corrosives (13.68%), sedatives/hypnotics (13.18%), pesticides (12.16%), hydrocarbon oils (8.61%) and others. Majority (60.64%) of the cases was accidental and occurred at home (66.72%) and most (87.33%) were referred from primary health centers. Median time between event and arrival at primary care center was 1 hour while median time to arrival at the hospital was 11 hours. There were 89 deaths (mortality 15.03%) in the series. Male gender, rural residence, referred status and non-use of specific antidotes had negative impact on survival. Conclusion: This large prospective study from eastern India from a hospital perspective, has captured data not only on the incidence and nature of poisoning but also on treatment trends and mortality outcomes. Field studies conducted in the light of these results will clarify additional issues.

IntroductionAyushman Bharat Pradhan Mantri Jan Aarogya Yojana (AB PM-JAY) has enabled the Government of India to become a strategic purchaser of health care services from private providers. To generate base cost evidence for evidence-based policymaking the Costing of Health Services in India (CHSI) study was commissioned in 2018 for the price setting of health benefit packages. This paper reports the findings of a process evaluation of the cost data collection in the private hospitals.MethodsThe process evaluation of health system costing in private hospitals was an exploratory survey with mixed methods (quantitative and qualitative). We used three approaches-an online survey using a semi-structured questionnaire, in-depth interviews, and a review of monitoring data. The process of data collection was assessed in terms of time taken for different aspects, resources used, level and nature of difficulty encountered, challenges and solutions.ResultsThe mean time taken for data collection in a private hospital was 9.31 (± 1.0) person months including time for obtaining permissions, actual data collection and entry, and addressing queries for data completeness and quality. The longest time was taken to collect data on human resources (30%), while it took the least time for collecting information on building and space (5%). On a scale of 1 (lowest) to 10 (highest) difficulty levels, the data on human resources was the most difficult to collect. This included data on salaries (8), time allocation (5.5) and leaves (5).DiscussionCost data from private hospitals is crucial for mixed health systems. Developing formal mechanisms of cost accounting data and data sharing as pre-requisites for empanelment under a national insurance scheme can significantly ease the process of cost data collection.

Objectives: Blood counts are commonly performed tests in neonatal intensive care units with the results having various clinical ramifications. Interpreting blood counts as normal or abnormal requires reference ranges as per gestation. Studies on reference ranges for neonatal neutrophil counts are already scarce, and data is lacking in the Asian context. We sought to formulate gestation-wise reference ranges of neutrophil counts in an Indian setting. Methods: Healthy, newborn babies of either gender, aged between 30 to 41 weeks gestation were included in the study. Gestational age was corroborated through first trimester dating scan and postnatally by the New Ballard Score. Single venous blood samples were drawn on day three and day five for estimation of total leukocyte count, differential count (neutrophils, lymphocytes), and peripheral blood smear examination. Results: We evaluated the data of 420 newborns. The normative values were compiled week-wise for gestational ages of 30 to 41 weeks at birth. We observed a clustering of neutrophil count values below 8000 cells/μL on day three and below 5000 cells/μL on day five. No gender-based differences in counts were observed. We were able to generate reference range curves for neutrophil counts as per gestational age. Conclusions: The absolute neutrophil counts of term and preterm Indian newborns are higher than the values depicted in the standard reference chart used currently. This indicates that a different standard chart as per gestation should be used in Indo-Asian countries to differentiate ‘normal’ from ‘abnormal’.

Background and Aims: Irritable bowel syndrome (IBS) is a chronic relapsing disorder characterized by abdominal pain-discomfort and altered bowel habits. The IBS-diarrhoea predominant subtype (IBS-D) is defined as >25% of bowel movements representing type 6 or 7 of the Bristol Stool Form Scale. Management of IBS-D is mainly symptomatic, including lifestyle modification. Due to absence of standard treatment, multiple drugs are used. A controlled release (CR) form of mebeverine, recommended for spasmodic gastrointestinal disorders (including IBS) has recently been introduced in Indian market. We have conducted a placebo-controlled double blind randomized controlled trial [CTRI/2018/03/012897] to evaluate the effectiveness and safety of this product. Methods: 40 patients of IBS-D were recruited from medicine out-patient department (OPD) of a tertiary care hospital and randomized to two parallel groups. One received mebeverine 200 mg CR tablets twice daily for 8 weeks, while other received matching placebo. Outcome parameters were number of bowel movements per day over past 7 days (NoBM7d), severity of abdominal cramps and IBS quality of life (IBSQoL) score. Medication adherence record and treatment emergent adverse events were captured. Results: Mebeverine group showed modest but statistically significant improvement in NoBM7d, cramps and IBSQoL from baseline to 4 and 8 weeks. The changes within the placebo group were not statistically significant. Also, the intergroup differences at both 4 and 8 weeks were not statistically significant. Adherence was better in mebeverine group and both interventions were well tolerated. Conclusions: Mebeverine 200 mg CR twice daily has modest effect in IBS-D and therefore will not be a good choice for patients with severe symptoms.

Objective: Childhood disabilities are common and impose a significant handicap on the affected children and their caregivers. There are limited data on the prevalence of childhood disabilities as assessed by specialist evaluation. We aimed to explore the spectrum of childhood disabilities in a cohort of rural children in North Bengal. Materials and Methods: A descriptive observational study was done in a tertiary care center of rural North Bengal over 2 years. Children aged between 2 and 12 years with some form of disability were included in the study. The demographic and socioeconomic profile and potential risk factors were recorded. Assessment was done by a multidisciplinary team involving pediatricians and faculty from other relevant disciplines. Relevant national guidelines were followed in assessing individual disabilities and their severity. Results: Four hundred and ninety-one disabled children were included in the study. The prevalence of childhood disability was approximately 2/10,000. Majority had multiple disabilities (56.62%). Sixty-one percent of the children were male, and the majority hailed from low-income families. Combination of locomotor disability and mental retardation was the most common form of disability, pure locomotor disability being the next most common. Proportions of visual and hearing impairment were 15.28% and 13.65%, respectively; 20.57% of the children had moderate to profound mental retardation, and 2.65% were diagnosed with mental illness. Consanguineous parents were noted in 12.42%, and one or more adverse perinatal events were recorded in the great majority of cases. Conclusions: This study exclusively on children by team of specialist medical personnel can serve as an index study profiling childhood disability in rural India.

We thank Dr. Al-Mendalawi for his comments on our study of gestation-wise reference ranges of neutrophil counts in Indian newborns.

Objectives: We sought to evaluate the relationship between gestational age (GA) and neonatal anthropometric parameters, namely head circumference (HC) and crown-heel length (CHL). Methods: We conducted a cross-sectional study in a tertiary care hospital with 530 consecutively live-born newborns of 28–41 weeks gestation. Anthropometric parameters were measured after three days of life. We summarized the variables using descriptive statistics, including percentile values, and the strength of association was determined through correlation analysis. The correlation was strong for HC and CHL, and linear regression analysis was done to develop predictive equations. Results: HC and CHL correlated well with GA with r-values of 0.863 and 0.859, respectively. The regression equations derived were GA (week) = 9.2671 + [0.8616 × HC (cm)] and GA (weeks) = 7.2489 + [0.621 × CHL (cm)]. Multiple regression gave the relationship as GA (weeks) = 4.0244 + [0.4058 × HC (cm)] + [0.4249× CHL (cm)]. Application of this multiple regression equation to a test cohort of 30 babies for prediction of GA gave a mean margin of error of 2.9%, indicating that it is a satisfactory tool for prediction. Conclusions: HC and CHL can be used as simple tools for predicting GA in babies when this is in doubt. This can help in identification of high-risk newborns at primary care level without recourse to imaging modalities.

Introduction: Lifestyle modification has an important role to play for the success of organ transplantation. In renal transplant recipients, recommended lifestyle measures include proper diet, exercise, clinic visits, monitoring and laboratory investigations as per schedule, protection against infections, and abstinence from addictions. The objective of the present study was to assess the compliance with lifestyle recommendations following kidney transplantation and to identify the potential determinants of noncompliance. Materials and Methods: This was a longitudinal study with 153 adult individuals attending the nephrology posttransplant clinic of one tertiary care government and two private hospitals in Kolkata. Participants were followed up for 1 year at 3-month intervals. A pretested questionnaire was used to screen for noncompliance in seven lifestyle areas, and if noncompliance was identified, its extent was assessed, and individuals probed further to explore potential determinants of noncompliance. Results: 64.1% of the transplant recipients were compliant with the recommended lifestyle measures overall. Separately, compliance rates were dietary 83.66%, clinic attendance 88.23%, self-monitoring or home monitoring 89.54%, laboratory investigations completion 88.23%, infection prevention 93.46%, and abstinence from addiction 95.42%. No statistical analysis was done for exercise compliance as recommendations were judged inconsistent and inadequate. Logistic regression analysis revealed that number of comorbidities, number of adverse reactions to prescribed drugs, and perceived severity of the disease were significantly associated with noncompliance. Conclusions: Overall compliance with lifestyle recommendations was suboptimum. The noncompliance risk factors identified need to be probed further.

Context: Hyperglycemia has been found to occur during myocardial infarction and cardiac surgery even in nondiabetic patients. These being essentially stressful processes associated with hypoperfusion, we decided to find a possible relationship between the occurrence of global tissue hypoperfusion (GTH) and elevated blood glucose level in adult nondiabetic patients undergoing elective off-pump coronary artery bypass grafting (CABG). Aims: This study aims to observe for the occurrence of global tissue hypoperfusion and its effect on blood glucose level and whether raised blood glucose level can be used as a marker for GTH. Design: Prospective, observational study. Settings: Cardiothoracic operation theater and intensive care unit of a tertiary care teaching hospital. Materials and Methods: The occurrence of global tissue hypoperfusion were detected with the help of combined markers of mixed venous oxygen saturation and arterial lactate level at various perioperative study points together with arterial blood glucose level. Blood glucose level compared between the patients with and without GTH. Statistical Analysis Used: Numerical variables were compared between groups by Student's t-test and categorical variables by Fisher's exact test. Two-tailed P ≤ 0.05 was considered for statistically significant. Results: The incidence of GTH was 67%. Blood glucose level was raised in patients with GTH at some study time points but with poor sensitivity and specificity values. Conclusions: Global tissue hypoperfusion is a common occurrence in even nondiabetic patients undergoing elective off-pump CABG. A relationship exists between rise in blood glucose level and global tissue hypoperfusion in such patients, although it cannot be viewed as marker of the same.

Objective: To evaluate the role of exponential apparent diffusion coefficient (ADC) as a tool for differentiating benign and malignant breast lesions. Patients and Methods: This prospective observational study included 88 breast lesions in 77 patients (between 18 and 85 years of age) who underwent 3T breast magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) using b-values of 0 and 800 s/mm2 before biopsy. Mean exponential ADC and ADC of benign and malignant lesions obtained from DWI were compared. Receiver operating characteristics (ROC) curve analysis was undertaken to identify any cut-off for exponential ADC and ADC to predict malignancy. P value of 0.4 (P < 0.0001) for malignant lesions, 93.9% sensitivity and 82.6% specificity was obtained. The performance of ADC and exponential ADC in distinguishing benign and malignant breast lesions based on respective cut-offs was comparable (P = 0.109). Conclusion: Exponential ADC can be used as a quantitative adjunct tool for characterizing breast lesions with comparable sensitivity and specificity as that of ADC.

In observational studies, as well as in interventional ones, it is frequently necessary to estimate risk that is the association between an observed outcome or event and exposure to one or more factors that may be contributing to the event. Understanding incidence and prevalence are the starting point in any discussion of risk assessment. Incidence rate uses person-time as the denominator rather than a simple count. Ideally, rates and ratios estimated from samples should be presented with their corresponding 95% confidence intervals (CIs). To assess the importance of an individual risk factor, it is necessary to compare the risk of the outcome in the exposed group with that in the nonexposed group. A comparison between risks in different groups can be made by examining either their ratio or the difference between them. The 2 × 2 contingency table comes in handy in the calculation of ratios. Odds ratio (OR) is the ratio of the odds of an event in the exposed group, to the odds of the same event in the nonexposed group. It can range from zero to infinity. When the odds of an outcome in the two groups are identical, then the OR equals one. OR >1 indicates exposure increases risk while OR

Crucial therapeutic decisions are based on diagnostic tests. Therefore, it is important to evaluate such tests before adopting them for routine use. Although things such as blood tests, cultures, biopsies, and radiological imaging are obvious diagnostic tests, it is not to be forgotten that specific clinical examination procedures, scoring systems based on physiological or psychological evaluation, and ratings based on questionnaires are also diagnostic tests and therefore merit similar evaluation. In the simplest scenario, a diagnostic test will give either a positive (disease likely) or negative (disease unlikely) result. Ideally, all those with the disease should be classified by a test as positive and all those without the disease as negative. Unfortunately, practically no test gives 100% accurate results. Therefore, leaving aside the economic question, the performance of diagnostic tests is evaluated on the basis of certain indices such as sensitivity, specificity, positive predictive value, and negative predictive value. Likelihood ratios combine information on specificity and sensitivity to expresses the likelihood that a given test result would occur in a subject with a disorder compared to the probability that the same result would occur in a subject without the disorder. Not all test can be categorized simply as “positive” or “negative.” Physicians are frequently exposed to test results on a numerical scale, and in such cases, judgment is required in choosing a cutoff point to distinguish normal from abnormal. Naturally, a cutoff value should provide the greatest predictive accuracy, but there is a trade-off between sensitivity and specificity here - if the cutoff is too low, it will identify most patients who have the disease (high sensitivity) but will also incorrectly identify many who do not (low specificity). A receiver operating characteristic curve plots pairs of sensitivity versus (1 − specificity) values and helps in selecting an optimum cutoff – the one lying on the “elbow” of the curve. Cohen's kappa (κ) statistic is a measure of inter-rater agreement for categorical variables. It can also be applied to assess how far two tests agree with respect to diagnostic categorization. It is generally thought to be a more robust measure than simple percent agreement calculation since kappa takes into account the agreement occurring by chance.

Multivariate analysis refers to statistical techniques that simultaneously look at three or more variables in relation to the subjects under investigation with the aim of identifying or clarifying the relationships between them. These techniques have been broadly classified as dependence techniques, which explore the relationship between one or more dependent variables and their independent predictors, and interdependence techniques, that make no such distinction but treat all variables equally in a search for underlying relationships. Multiple linear regression models a situation where a single numerical dependent variable is to be predicted from multiple numerical independent variables. Logistic regression is used when the outcome variable is dichotomous in nature. The log-linear technique models count type of data and can be used to analyze cross-tabulations where more than two variables are included. Analysis of covariance is an extension of analysis of variance (ANOVA), in which an additional independent variable of interest, the covariate, is brought into the analysis. It tries to examine whether a difference persists after “controlling” for the effect of the covariate that can impact the numerical dependent variable of interest. Multivariate analysis of variance (MANOVA) is a multivariate extension of ANOVA used when multiple numerical dependent variables have to be incorporated in the analysis. Interdependence techniques are more commonly applied to psychometrics, social sciences and market research. Exploratory factor analysis and principal component analysis are related techniques that seek to extract from a larger number of metric variables, a smaller number of composite factors or components, which are linearly related to the original variables. Cluster analysis aims to identify, in a large number of cases, relatively homogeneous groups called clusters, without prior information about the groups. The calculation intensive nature of multivariate analysis has so far precluded most researchers from using these techniques routinely. The situation is now changing with wider availability, and increasing sophistication of statistical software and researchers should no longer shy away from exploring the applications of multivariate methods to real-life data sets.

Survival analysis is concerned with “time to event“ data. Conventionally, it dealt with cancer death as the event in question, but it can handle any event occurring over a time frame, and this need not be always adverse in nature. When the outcome of a study is the time to an event, it is often not possible to wait until the event in question has happened to all the subjects, for example, until all are dead. In addition, subjects may leave the study prematurely. Such situations lead to what is called censored observations as complete information is not available for these subjects. The data set is thus an assemblage of times to the event in question and times after which no more information on the individual is available. Survival analysis methods are the only techniques capable of handling censored observations without treating them as missing data. They also make no assumption regarding normal distribution of time to event data. Descriptive methods for exploring survival times in a sample include life table and Kaplan–Meier techniques as well as various kinds of distribution fitting as advanced modeling techniques. The Kaplan–Meier cumulative survival probability over time plot has become the signature plot for biomedical survival analysis. Several techniques are available for comparing the survival experience in two or more groups – the log-rank test is popularly used. This test can also be used to produce an odds ratio as an estimate of risk of the event in the test group; this is called hazard ratio (HR). Limitations of the traditional log-rank test have led to various modifications and enhancements. Finally, survival analysis offers different regression models for estimating the impact of multiple predictors on survival. Cox's proportional hazard model is the most general of the regression methods that allows the hazard function to be modeled on a set of explanatory variables without making restrictive assumptions concerning the nature or shape of the underlying survival distribution. It can accommodate any number of covariates, whether they are categorical or continuous. Like the adjusted odds ratios in logistic regression, this multivariate technique produces adjusted HRs for individual factors that may modify survival.

Objective: The objective of this study is to delineate the clinical and laboratory profile of infectious mononucleosis due to Epstein-Barr virus (EBV) infection in children admitted to tertiary care teaching hospitals. Materials and Methods: Retrospective observational multicentric analysis of clinical and laboratory features of children between 1 month to 12 years with a diagnosis of infectious mononucleosis due to EBV infection confirmed by positive serology over a 12-month period after seeking approval from the Institutional Ethics Committee. Results: Out of 66 children screened, 53 were included in final analysis. The majority were aged between 5 and 8 years with male: female ratio of 1.2:1. Most presentations were during the monsoon months. The common clinical features were fever (100%), splenomegaly (86.7%), and cervical lymphadenopathy (73.5%) in contrast to the classical triad of fever, sore throat, and generalized lymphadenopathy described in the literature. There were no age differences in clinical findings except for generalized and cervical lymphadenopathy and hepatomegaly which were commoner in 9–12 years age band. Although the incidence of common findings matched with previously published studies, there were some notable differences. While frequencies of upper eyelid edema, epitrochlear lymphadenopathy, and splenomegaly were more, those of rash and sore throat were less. Lymphocytosis and presence of atypical lymphocytes were relatively less common in our series. All children recovered. Conclusions: This multicentric study on profiling childhood infectious mononucleosis, possibly first of its kind from Eastern India, has documented clinical and laboratory features associated with this condition. These data can serve as a reference for future studies.

Context: Caregivers of sick children have to be careful with medicine dosing and giving medicines to a reluctant child can be challenging. Aim: To assess the knowledge, attitude, and practices of caregivers regarding pediatric medicine administration and health literacy allied to this task. Settings and Design: This cross-sectional study was carried out on outpatient and inpatient basis in the pediatrics department of a teaching hospital over 6 months. Subjects and Methods: Data regarding sociodemographic profile of patient and caregiver, idea regarding pediatric dosage forms, dosing of medicines, and medication errors during administration were recorded from 377 caregivers. Reconstitution of dry powder and measurement of 5 mL liquid medicine using measuring cup of the medicine phial was demonstrated by the caregivers. Statistical Analysis: Association assessed by point biserial correlation and Spearman's rank correlation. Results: Majority of the primary caregivers surveyed were young, educated, homemaker mothers. Liquid medicines were used maximally (88.9%). Majority (87.3%) of the caregivers used standardized dosing instruments to measure liquids and reconstitution (85.9%), and teaspoon measurement task (91%) was performed satisfactorily by most. Some potentially wrong practices (e.g., adding medicine to milk, redilution of reconstituted medicine, and storing beyond the recommended period) were recorded. Medication errors were reported by 44.5% caregivers, significantly more in the outpatient setting. Although the statistical correlation was weak, the chance of medication error was less, and the precision of measurement was better with increasing education of the caregiver. Conclusions: Physicians need to be aware of the limitations of knowledge and the possibility of wrong administration practices among caregivers of children. Remedial measures in this regard can reduce the risk of medication errors.

Hypothesis testing (or statistical inference) is one of the major applications of biostatistics. Much of medical research begins with a research question that can be framed as a hypothesis. Inferential statistics begins with a null hypothesis that reflects the conservative position of no change or no difference in comparison to baseline or between groups. Usually, the researcher has reason to believe that there is some effect or some difference which is the alternative hypothesis. The researcher therefore proceeds to study samples and measure outcomes in the hope of generating evidence strong enough for the statistician to be able to reject the null hypothesis. The concept of the P value is almost universally used in hypothesis testing. It denotes the probability of obtaining by chance a result at least as extreme as that observed, even when the null hypothesis is true and no real difference exists. Usually, if P is < 0.05 the null hypothesis is rejected and sample results are deemed statistically significant. With the increasing availability of computers and access to specialized statistical software, the drudgery involved in statistical calculations is now a thing of the past, once the learning curve of the software has been traversed. The life sciences researcher is therefore free to devote oneself to optimally designing the study, carefully selecting the hypothesis tests to be applied, and taking care in conducting the study well. Unfortunately, selecting the right test seems difficult initially. Thinking of the research hypothesis as addressing one of five generic research questions helps in selection of the right hypothesis test. In addition, it is important to be clear about the nature of the variables (e.g., numerical vs. categorical; parametric vs. nonparametric) and the number of groups or data sets being compared (e.g., two or more than two) at a time. The same research question may be explored by more than one type of hypothesis test. While this may be of utility in highlighting different aspects of the problem, merely reapplying different tests to the same issue in the hope of finding a P < 0.05 is a wrong use of statistics. Finally, it is becoming the norm that an estimate of the size of any effect, expressed with its 95% confidence interval, is required for meaningful interpretation of results. A large study is likely to have a small (and therefore “statistically significant”) P value, but a “real” estimate of the effect would be provided by the 95% confidence interval. If the intervals overlap between two interventions, then the difference between them is not so clear-cut even if P < 0.05. The two approaches are now considered complementary to one another.

Categorical variables are commonly represented as counts or frequencies. For analysis, such data are conveniently arranged in contingency tables. Conventionally, such tables are designated as r × c tables, with r denoting number of rows and c denoting number of columns. The Chi-square (χ2 ) probability distribution is particularly useful in analyzing categorical variables. A number of tests yield test statistics that fit, at least approximately, a χ2 distribution and hence are referred to as χ2 tests. Examples include Pearson′s χ2 test (or simply the χ2 test), McNemar′s χ2 test, Mantel-Haenszel χ2 test and others. The Pearson′s χ2 test is the most commonly used test for assessing difference in distribution of a categorical variable between two or more independent groups. If the groups are ordered in some manner, the χ2 test for trend should be used. The Fisher′s exact probability test is a test of the independence between two dichotomous categorical variables. It provides a better alternative to the χ2 statistic to assess the difference between two independent proportions when numbers are small, but cannot be applied to a contingency table larger than a two-dimensional one. The McNemar′s χ2 test assesses the difference between paired proportions. It is used when the frequencies in a 2 × 2 table represent paired samples or observations. The Cochran′s Q test is a generalization of the McNemar′s test that compares more than two related proportions. The P value from the χ2 test or its counterparts does not indicate the strength of the difference or association between the categorical variables involved. This information can be obtained from the relative risk or the odds ratio statistic which is measures of dichotomous association obtained from 2 × 2 tables.

Background: The rising incidence of stroke in India indicates the importance of evaluating the existing knowledge, attitude, and practice (KAP) in the community, which is essential for stroke control. Objective: To explore and compare stroke-related KAP among participants from stroke-affected families (SAFs) and nonstroke-affected families (NSFs). Design: Using stratified random sampling, a three-phase house-to-house survey was conducted in Kolkata, West Bengal, India. First, field investigators screened subjects of stroke; second, the neurologist confirmed positive cases; and third, under supervision of the neuropsychologist, a validated questionnaire on KAP was administered to participants from SAFs and age-matched NSAFs from the same neighborhood. Results: The KAP questionnaire was administered to 282 participants each from both groups. Knowledge about stroke prevailed in 97% participants and was significantly higher in the SAF group. Both SAF and NSAF groups had better knowledge about prominent symptoms of stroke (loss of consciousness and paralysis) and admitted it as emergency situation requiring hospitalization and that it was potentially preventable. Those persons belonging to the SAF group, however, had lesser knowledge of the risk factors such as diabetes (P < 0.001), smoking (P < 0.014), alcoholism (P < .0.0001), family history (P < .0.0001) and mild stroke symptoms such as headache, (P < 0.001), vomiting (P < 0.001), and fits (P 0.003) as compared to the NSAF group. Conclusions: Persons from both SAF and non-SAF groups are aware about stroke but possess lesser knowledge about the many symptoms of stroke and risk factors, indicating the necessity of enhancement of existence knowledge on symptoms for better diagnosis and of risk factors for better prevention.

Context: It is well established that breast cancer subtypes differ in their outcome and treatment response. Aim: To observe tumor characteristics of different molecular subgroup and patients with postoperative (PO) raised cancer antigen 15.3 (CA 15.3) group and variation of tumor nature between pre- and post-menopausal breast cancer patients. Materials and Methods: Blood samples and tumor blocks were collected from 95 nonmetastatic female breast cancer patients. Immunohistochemical stains for estrogen receptors (ER), progesterone receptor (PR), and HER2/Neu were used to classify molecular subtypes. CA 15.3 level was detected by ELISA. Significance levels were ascertained by Pearson Chi-square test. Results: Prevalence of luminal A tumor with grade 3 was high. Triple negative and ER positive (ER+) types showed tumors with high grade and high lymph node (LN) metastasis. More nodal involvement was noticed in patients with PO raised CA 15.3. In addition, premenopausal patients with triple-negative and ER+ subtypes exhibited more aggressive tumors which were characterized by high grade and large numbers of LN metastasis. Conclusion: Clinicopathological characteristics of certain molecular subtypes and influence of menopausal status on it can predict disease recurrence or overall survival of breast cancer patients.

Although application of statistical methods to biomedical research began only some 150 years ago, statistics is now an integral part of medical research. A knowledge of statistics is also becoming mandatory to understand most medical literature. Data constitute the raw material for statistical work. They are records of measurement or observations or simply counts. A variable refers to a particular character on which a set of data are recorded. Data are thus the values of a variable. It is important to understand the different types of data and their mutual interconversion. Biostatistics begins with descriptive statistics that implies summarizing a collection of data from a sample or population. Categorical data are described in terms of percentages or proportions. With numerical data, individual observations within a sample or population tend to cluster about a central location, with more extreme observations being less frequent. The extent to which observations cluster is summarized by measures of central tendency while the spread can be described by measures of dispersion. The confidence interval (CI) is an increasingly important measure of precision. When we observe samples, there is no way of assessing true population parameters. We can, however, obtain a standard error and use it to define a range in which the true population value is likely to lie with a certain acceptable level of uncertainty. This range is the CI while its two terminal values are the confidence limits. Conventionally, the 95% CI is used. Patterns in data sets or data distributions are important, albeit not so obvious, component of descriptive statistics. The most common distribution is the normal distribution which is depicted as the well-known symmetrical bell-shaped Gaussian curve. Familiarity with other distributions such as the binomial and Poisson distributions is also helpful. Various graphs and plots have been devised to summarize data and trends visually. Some plots, such as the box-and-whiskers plot and the stem-and-leaf plot are used less often but provide useful summaries in select situations.

Determining the appropriate sample size for a study, whatever be its type, is a fundamental aspect of biomedical research. An adequate sample ensures that the study will yield reliable information, regardless of whether the data ultimately suggests a clinically important difference between the interventions or elements being studied. The probability of Type 1 and Type 2 errors, the expected variance in the sample and the effect size are the essential determinants of sample size in interventional studies. Any method for deriving a conclusion from experimental data carries with it some risk of drawing a false conclusion. Two types of false conclusion may occur, called Type 1 and Type 2 errors, whose probabilities are denoted by the symbols σ and β. A Type 1 error occurs when one concludes that a difference exists between the groups being compared when, in reality, it does not. This is akin to a false positive result. A Type 2 error occurs when one concludes that difference does not exist when, in reality, a difference does exist, and it is equal to or larger than the effect size defined by the alternative to the null hypothesis. This may be viewed as a false negative result. When considering the risk of Type 2 error, it is more intuitive to think in terms of power of the study or (1 − β). Power denotes the probability of detecting a difference when a difference does exist between the groups being compared. Smaller α or larger power will increase sample size. Conventional acceptable values for power and α are 80% or above and 5% or below, respectively, when calculating sample size. Increasing variance in the sample tends to increase the sample size required to achieve a given power level. The effect size is the smallest clinically important difference that is sought to be detected and, rather than statistical convention, is a matter of past experience and clinical judgment. Larger samples are required if smaller differences are to be detected. Although the principles are long known, historically, sample size determination has been difficult, because of relatively complex mathematical considerations and numerous different formulas. However, of late, there has been remarkable improvement in the availability, capability, and user-friendliness of power and sample size determination software. Many can execute routines for determination of sample size and power for a wide variety of research designs and statistical tests. With the drudgery of mathematical calculation gone, researchers must now concentrate on determining appropriate sample size and achieving these targets, so that study conclusions can be accepted as meaningful.

Numerical data that are normally distributed can be analyzed with parametric tests, that is, tests which are based on the parameters that define a normal distribution curve. If the distribution is uncertain, the data can be plotted as a normal probability plot and visually inspected, or tested for normality using one of a number of goodness of fit tests, such as the Kolmogorov–Smirnov test. The widely used Student's t-test has three variants. The one-sample t-test is used to assess if a sample mean (as an estimate of the population mean) differs significantly from a given population mean. The means of two independent samples may be compared for a statistically significant difference by the unpaired or independent samples t-test. If the data sets are related in some way, their means may be compared by the paired or dependent samples t-test. The t-test should not be used to compare the means of more than two groups. Although it is possible to compare groups in pairs, when there are more than two groups, this will increase the probability of a Type I error. The one-way analysis of variance (ANOVA) is employed to compare the means of three or more independent data sets that are normally distributed. Multiple measurements from the same set of subjects cannot be treated as separate, unrelated data sets. Comparison of means in such a situation requires repeated measures ANOVA. It is to be noted that while a multiple group comparison test such as ANOVA can point to a significant difference, it does not identify exactly between which two groups the difference lies. To do this, multiple group comparison needs to be followed up by an appropriate post hoc test. An example is the Tukey's honestly significant difference test following ANOVA. If the assumptions for parametric tests are not met, there are nonparametric alternatives for comparing data sets. These include Mann–Whitney U-test as the nonparametric counterpart of the unpaired Student's t-test, Wilcoxon signed-rank test as the counterpart of the paired Student's t-test, Kruskal–Wallis test as the nonparametric equivalent of ANOVA and the Friedman's test as the counterpart of repeated measures ANOVA.

Correlation and linear regression are the most commonly used techniques for quantifying the association between two numeric variables. Correlation quantifies the strength of the linear relationship between paired variables, expressing this as a correlation coefficient. If both variables x and y are normally distributed, we calculate Pearson′s correlation coefficient (r). If normality assumption is not met for one or both variables in a correlation analysis, a rank correlation coefficient, such as Spearman′s rho (ρ) may be calculated. A hypothesis test of correlation tests whether the linear relationship between the two variables holds in the underlying population, in which case it returns a P < 0.05. A 95% confidence interval of the correlation coefficient can also be calculated for an idea of the correlation in the population. The value r2 denotes the proportion of the variability of the dependent variable y that can be attributed to its linear relation with the independent variable x and is called the coefficient of determination. Linear regression is a technique that attempts to link two correlated variables x and y in the form of a mathematical equation (y = a + bx), such that given the value of one variable the other may be predicted. In general, the method of least squares is applied to obtain the equation of the regression line. Correlation and linear regression analysis are based on certain assumptions pertaining to the data sets. If these assumptions are not met, misleading conclusions may be drawn. The first assumption is that of linear relationship between the two variables. A scatter plot is essential before embarking on any correlation-regression analysis to show that this is indeed the case. Outliers or clustering within data sets can distort the correlation coefficient value. Finally, it is vital to remember that though strong correlation can be a pointer toward causation, the two are not synonymous.

Background and Aims: We aimed to evaluate and compare the block characteristics and duration of analgesia of intrathecal isobaric ropivacaine-fentanyl and bupivacaine-fentanyl combination in adult patients undergoing lower limb orthopedic surgery. Material and Methods: Seventy-four American Society of Anesthesiologists′ I and II adult patients undergoing lower limb orthopedic surgery under subarachnoid block were randomized to receive either 3 ml 0.5% isobaric ropivacaine and 25 mcg fentanyl (Group R) or 3 ml 0.5% isobaric bupivacaine and 25 mcg fentanyl (Group B). The hemodynamic profiles, maximum upper level of sensory block height, time to reach peak block height, two dermatome regression time, and duration of motor block were recorded. Results: There was no statistically significant difference regarding the hemodynamic parameters between the groups. The median (range) peak sensory block height was T7 (T4-T9) in Group R and T7 (T4-T10) in Group B. Time to reach peak block height (13.2 ± 2.3 min in Group R vs. 13.7 ± 2.2 min in Group B; P = 0.385) was similar between the groups. Two dermatome regression time in sensory block (median 120 min vs. 85 min; P < 0.001) and duration of motor block (median 245 min vs. 150 min; P < 0.001) was significantly higher in Group B. The duration of analgesia (median 360 min vs. 245 min; P < 0.001) was significantly higher in the bupivacaine group. Conclusion: Intrathecal isobaric bupivacaine-fentanyl combination produces a significantly longer duration of analgesia, sensory block and motor block than isobaric ropivacaine-fentanyl combination. As ropivacaine has a shorter duration of sensory and motor block, it may be preferred in day care surgery.

Objectives: Low birth weight (LBW;

CONTEXT: There is limited evidence on the influence of social media among medical students. AIMS: To assess the pattern of social media usage among medical students in eastern part of India and analyze self-perceived impact on academic performance and interpersonal relations. Methods: This cross-sectional study was based on an online survey, taken by 650 medical students at a tertiary medical center in Kolkata. The survey was created using an online tool, Google Forms. It assessed social media usage patterns and students' perspective on how it affects their academic performance and interpersonal relations. STATISTICAL ANALYSIS USED: Pearson's correlation coefficient was used to quantify the association between self-rated academic performance and social and physical well-being, with different variables, assuming linear relationships. P

Background and Objective: A proficient pathogen should be virulent, resistant to antibiotics, and epidemic. However, the interplay between resistance and virulence is poorly understood. Perhaps, the most commonly accepted view is that resistance to quinolones is linked to a loss of virulence factors. However, the low virulent phylogenetic groups may be more prone to acquire resistance to quinolones. The aim of this study was to identify and characterise the Nalidixic Acid (NA) and ciprofloxacin (CIP) resistant uropathogenic Escherichia coli (UPEC) isolates with respect to virulence and phylogenetic background, from hospital settings in Kolkata, an eastern region in India. Research based on these bacterial populations will help in understanding the molecular mechanisms underlying the association between resistance and virulence, that in turn, may help in managing the future disseminations of UTIs in their entirety. Material and Methods: One hundred and ten E. coli isolates were screened against NA and CIP using Kirby-Bauer disk diffusion technique, following CLSI guidelines. Prevalence of virulent factor genes and distribution of phylogenetic groups amongst the isolates was determined by PCR, using gene specific primers against the different virulent factors and DNA markers (chuA, yjaA and DNA fragment, TSPE4.C2) respectively. Statistical analysis of the data was performed using SPSS software. Results: Resistance to both NA and CIP was reported in 75.5 % of the isolates which were analysed. The virulent determinants, papC, pap GII, papEF, afa, cnf1, hlyA and iroN were significantly predominant in the drug susceptible than the resistant isolates. A significant reduction of phylogroup B2 in NA (85.7% versus 64.6%, χ2 P

To assess the success of dorsal onlay buccal mucosal graft (BMG) urethroplasty in long segment anterior urethral stricture extending from external meatus to bulbar urethra). We studied 40 patients with long segment anterior urethral stricture, who underwent substitution urethroplasty using dorsal onlay BMG from January 2002 to December 2007. The p atients were in the age range of 15-65 years (mean 35 years) in the LS group and 16-63 years (mean 34 years) in the non-lichen sclerosus (NLS) group. The cause of stricture was LS in 20 and NLS (inflammatory and idiopathic) in the other 20 patients. The mean stricture length was 14.5 cm (range 12-17 cm) in the LS group while it was 14.0 cm (range 12-16 cm) in the NLS group. The patients were evaluated with antegrade, retrograde urethrograms and sono-urethrograms and they were followed- up with uroflometery at three months for one year, then six- monthly for two years and then annually. The contrast studies were repeated at six-monthly intervals for one year and then annually for one year. Success was defined as normal voiding pattern without any intervention post-operatively. Median follow-up was 48 months (18-72 months) in the LS group, while it was 42 months (12-72 months) in the NLS group. Among the NLS group patients, three patients developed restricture on follow-up, while seven patients among the LS group developed restricture. We conclude that the high percentage of recurrence of strictures (35%) among the LS group renders BMG urethroplasty in long segment anterior urethral stricture an unacceptable solution, and it needs further study.