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With the increased prevalence of obesity worldwide, the incidence of obstructive sleep apnoea (OSA) has risen substantially. OSA is now also more commonly recognized within the pregnant population. The diagnosis of OSA during pregnancy is logistically difficult for many reasons. The symptoms of an uncomplicated pregnancy are traditionally believed to include sleep disruption and daytime sleepiness, without many specific data differentiating 'normal' from 'pathological', thus complicating the screening process for a true sleep disorder based on symptoms alone. Untreated OSA during pregnancy is associated with a variety of gestational health disorders, along with increased complications during delivery. Although screening protocols and increased healthcare provider awareness have led to earlier diagnosis and treatment of OSA in the general population, their implementation in the pregnant population is lacking. Studies on the use of continuous positive airway pressure in pregnancy have demonstrated its safety, but further research is needed to determine its benefits in this cohort. [ABSTRACT FROM AUTHOR]

Background: Pre-marketing clinical studies of tegaserod suggested an increased risk of abdominal surgery, particularly cholecystectomy. We sought to quantify the association between tegaserod use and the occurrence of abdominal or pelvic surgery, including cholecystectomy. Methods: This cohort study was conducted within an insured population. Tegaserod initiators and similar persons who did not initiate tegaserod were followed for up to six months for the occurrence of abdominal or pelvic surgery. Surgical procedures were identified from health insurance claims validated by review of medical records. The incidence of confirmed outcomes was compared using both as-matched and as-treated analyses. Results: Among 2,762 tegaserod initiators, there were 94 abdominal or pelvic surgeries (36 gallbladder): among 2,762 comparators there were 134 abdominal or pelvic surgeries (37 gallbladder) (hazard ratio HR] = 0.70, 95% confidence interval [C.I.] = 0.54-0.91 overall, HR = 0.98, 95% C.I. = 0.62-1.55 for gallbladder). Current tegaserod exposure compared to nonexposure was associated with a rate ratio [RR] of 0.68 (95% C.I. = 0.48-0.95) overall, while the RR was 0.99 (95% C.I. = 0.56-1.77) for gallbladder surgery. Conclusions: In this study, tegaserod use was not found to increase the risk of abdominal or pelvic surgery nor the specific subset of gallbladder surgery. [ABSTRACT FROM AUTHOR]

Purpose: To estimate the rate of new-onset afebrile provoked and unprovoked seizure in a general pediatric population and subgroups of patients with and without psychiatric diagnoses other than attention deficit hyperactivity disorder (ADHD). Methods: A retrospective cohort study of 133,440 pediatric patients, between the ages of 6 and 17 years, and without history of seizure or prior use of anticonvulsant medications, with follow-up during 2003. The data source for this study was Ingenix's research database containing pharmacy and medical claims for members of a large US-based managed care organization. The main outcome measure was new-onset nonfebrile seizure. Incidence rates of seizure and 95% confidence intervals (CI) were calculated and expressed as rates per 100,000 person-years. Results: There were 132 new-onset provoked and unprovoked seizures in 78,423 person-years of follow-up among the general pediatric population sample. The incidence rate of seizure among the general pediatric population was 168 per 100,000 p-y (95% CI 141–200). The incidence rate of seizure among patients without psychiatric diagnoses was 149 per 100,000 p-y (95% CI 122–180). The incidence rate of seizure among patients with psychiatric diagnoses other than ADHD was 513 per 100,000 p-y (95% CI 273–878). There were increases in the incidence rates of seizure in all of the seizure risk factor groups, but this was more pronounced among males ages 6–12 with psychiatric diagnoses. Conclusions: The results of this study are consistent with previous reports showing that pediatric patients with psychiatric disorders have a higher incidence rate of seizure than the general pediatric population. [ABSTRACT FROM AUTHOR]

BACKGROUND: To identify predictors of colon ischemia, we examined demographic and clinical characteristics of patients, as well as their prior health care utilization.METHODS: Using insurance data, we identified 700 persons at least 20-yr old with presumed colon ischemia between 1995 and 1999, and 6,440 controls. Case identification was based on diagnosis and procedure codes in insurance claims for which we used a previously reported, validated algorithm. We ascertained preceding medical diagnoses and the use of drugs and health services from the insurance claims files.RESULTS: Patients with colon ischemia were nearly three times as likely to have IBS than controls. A history of nonspecific colitis, lower gastrointestinal tract hemorrhage, systemic rheumatologic disorders, and ischemic heart disease in the preceding 6 months, and abdominal surgery in the past month were also much more common in colon ischemia cases than controls. Use of a drug to treat diarrhea was strongly associated with risk. The most prevalent risk factor for colon ischemia was the use of drugs with a side effect of constipation, found in one-third of cases and one in nine controls. Cases had seen physicians, particularly gastroenterologists, much more commonly in the preceding 6 months than had controls.CONCLUSIONS: Clinically evident colon ischemia arises preferentially in persons with prior abdominal complaints, many of whom carry a diagnosis of IBS. Drugs that reduce bowel motility may constitute a widespread and potentially avoidable risk factor. The frequency of preceding doctor visits, without a specific diagnosis, suggests that colon ischemia may have a prolonged subacute presentation. [ABSTRACT FROM AUTHOR]

Abstract: The areas of overlap of confidence intervals from several studies can be used to create summary confidence regions. These summary regions lend themselves to graphical display, have readily derivable statistical properties, and can carry information about the influence both of available studies and of hypothetical future investigations. The case of a region covered by at least N-1 out of N confidence intervals is presented in some detail. (Am J Public Health 1988; 78:961-966.) [ABSTRACT FROM AUTHOR]

We have explored the use of data from the Commission on Professional and Hospital Activities-Professional Activity Study (CPHA-PAS) for ascertaining information on cancer incidence, with regional breakdowns. Extirpative surgical procedures were linked with discharge diagnoses to provide estimates of numbers of incident cases. We calculated incidence rates for four cancers: breast, colon, ovary, and testis. CPHA-PAS inferred rates corresponded closely to those of other reporting systems for breast cancer in most age groups, and for colonic and testicular cancer in some age groups. Ovarian cancer rates were consistently underestimated. We conclude that a cancer incidence reporting scheme based on hospital discharge data can work for certain cancers, and be very inexpensive and efficient. It must, however, be used with care. [ABSTRACT FROM AUTHOR]

The authors developed and cross-validated prediction models for newty diagnosed cases of liver disorders by using logistic regression and neural networks. Computerized files of health care encounters from the Fallon Community Health Plan were used to identify 1,674 subjects who had had liver-related health services between July 1,1992, and June 30, 1993. A total of 219 subjects were confirmed by review of medical records as incident cases. The 1, 674 subjects were randomly and evenly divided into training and test sets. The training set was used to derive prediction algorithms based solely on the automated data; the test set was used for cross-validation. The area under the Receiver Operating Characteristic curve for a neural network model was significantly larger than that for logistic regression in the training set (p = 0.04). However, the performance was statistically equivalent in the test set (p = 0.45). Despite its superior performance in the training set, the generalizability of the neural network model is limited. Logistic regression may therefore be preferred over neural network on the basis of its established advantages. More generalizable modeling techniques for neural networks may be necessary before they are practical for medical research. Am J Epidemiol 1998; 147: 407–13. [ABSTRACT FROM AUTHOR]

The article points out ways in which clarity in reporting the results of epidemiological studies may be achieved. Clarity may be attained through attention to the methods of research and to the underlying substantive issues in the execution and reporting of a study. Ideas presented in the article are a collation of what the author believes to be successes in presentation that he has observed in other people's work and occasionally in his own. Important considerations are the context of the study, study subjects and the source of population, data collection and implications.

Background: Complications of influenza are a major cause of morbidity and mortality during the influenza season. Clinical trials of zanamivir have reported a reduced incidence of influenza complications among high-risk patients.Objectives: This retrospective study sought to determine whether the use of zanamivir lowers the risk of acute influenza complications in a broader population, based on an analysis of claims data from a large managed care organization.Methods: Medical and pharmacy health insurance claims data from October 1, 1999, through April 30, 2000, were compiled for UnitedHealthcare members in 19 states. All patients with a diagnosis of influenza (International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic code 487.xx) associated with a physician visit were identified. From these, all patients were selected who had received zanamivir on the same day as the diagnosis of influenza. The propensity score matching technique was used to identify a comparison group with similar health service utilization and comorbidities who received a diagnosis of influenza but no antiviral therapy. Follow-up started the day after the influenza diagnosis and continued for 21 days.Results: From the 43,741 patients originally identified, 2341 were selected who received a simultaneous diagnosis of influenza and a prescription for zanamivir. The untreated comparator group numbered 2337. Fewer zanamivir patients than untreated patients were hospitalized for complications, and the absolute risks were low (0.6% and 1.0%, respectively; risk ratio [RR], 0.58; 95% CI, 0.30–1.12). Zanamivir-treated patients had an excess of outpatient visits (16.9% vs 14.5%; RR, 1.16; 95% CI, 1.02–1.33) and antibiotic use (16.3% vs 14.8%; RR, 1.10; 95% CI, 0.97–1.26), although the RRs were modest.Conclusions: In the setting of a large managed care plan, patterns of influenza complications were similar in zanamivir-treated and untreated patients with a diagnosis of influenza. The results of this study are in contrast to those of published clinical trials reporting a reduction in the risk of influenza complications in zanamivir-treated patients. [Copyright &y& Elsevier]

Background: Inhaled zanamivir is indicated for treatment of uncomplicated acute illness due to influenza A and B viruses in patients aged ≥12 years who have been symptomatic for no more than 2 days.Objective: The primary objective of this study was to estimate the incidence of adverse respiratory events among zanamivir-treated patients under conditions of usual care.Methods: The Ingenix research database includes insurance claims for all dispensations, inpatient and outpatient services, and procedures including the associated diagnoses and costs for a subset of all enrolled UnitedHealthcare members. We identified all persons with a dispensation of zanamivir recorded between October 1, 1999, and April 30, 2000. We captured medical and pharmaceutical claims data for the 6 months before the dispensation to obtain information about comorbidities, overall health status, and respiratory events. Medical and hospital record abstraction and clinical review served to confirm inpatient/emergency department (ED) events. We also examined the records of an ∼ 10% random sample of patients treated for a potential respiratory event in an outpatient/physician office visit during the 10-day follow-up period. Respiratory events not sufficiently severe to result in medical care were not captured in this study.Results: A total of 5498 eligible zanamivir dispensations contributed by 5450 patients (2911 females, 2539 males; mean age, 38.8 years), with 40 confirmed inpatient/ED respiratory events, were included in the study. Of these 40 events, 31 were pneumonia, bronchitis, or exacerbations of existing chronic respiratory disease; none required intubation or ventilation. No events occurred on the dispensation date. The overall risk for an inpatient/ED respiratory event was 0.7 per 100 episodes (95% CI, 0.5–1.0). Seven events of wheezing or shortness of breath were not an obvious extension of the original influenza-like illness or of a complicating bronchitis (risk = 0.13 per 100 episodes; 95% CI, 0.06–0.26).Conclusions: No immediate or severe bronchoconstrictive responses occurred among 5498 zanamivir dispensations. The overall risk for any respiratory event was low, and none was sufficiently severe to suggest respiratory failure. [Copyright &y& Elsevier]

Purpose: The present study describes the patterns and predictors of treatment persistence and adherence among patients who are diagnosed with glaucoma or as glaucoma suspects (based on claims codes). Design: A retrospective cohort study using health insurance claims data. Methods: Newly treated individuals with diagnosed glaucoma (n = 3623) and suspect glaucoma (n = 1677) were obtained from healthcare claims data in the Ingenix Research Database. For each of these two diagnostic groups, we calculated the duration of continuous treatment with the initially prescribed medication (persistence) and the prevalence of use of the initial medication at various time points (adherence). Four drug classes were included: β-blockers, α-agonists, carbonic anhydrase inhibitors, and prostaglandin analogs. Results: Nearly one half of the individuals who had filled a glaucoma prescription discontinued all topical ocular hypotensive therapy within six months, and just 37% of these individuals recently had refilled their initial medication at three years after the first dispensing. Prostaglandins were associated with better persistence than any other drug class, which was indicated by hazard ratios for discontinuation of prostaglandins compared with β-blockers of 0.40 (95% confidence interval, 0.35–0.44) for diagnosed patients and 0.44 (95% confidence interval, 0.37–0.52) for patients with suspect glaucoma. Prostaglandins showed a similar advantage in adherence. Furthermore, patients with diagnosed glaucoma were more likely to adhere to therapy than patients with suspect glaucoma (relative risk = 1.11; 95% confidence interval, 1.05–1.18). Conclusion: Persistence and adherence were substantially better with prostaglandins than with other drug classes, and patients with diagnosed open-angle glaucoma were more likely to adhere to treatment than suspected glaucoma. [Copyright &y& Elsevier]