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Objectives: This study aimed to determine the associations between income level and stroke incidence in hypertensive patients. We also tried to measure the mediating effect of poor antihypertensive medication adherence through causal mediation analysis. Methods: This study used the National Health Insurance Service National Sample Cohort Data from 2006 to 2015. The study population was newly diagnosed patients with hypertension aged 18 to 80. The associations between the independent-dependent variables, the mediator-dependent variables were confirmed with Cox proportional hazards regression models. In order to verify the mediating effect of poor hypertension medication adherence between income level and stroke occurrence, a weighting approach of causal mediation analysis method was used. Since age was the moderate variable, 18-49 years old and 50-80 years old were stratified. Results: Under 50 years of age, all the other income groups had a significantly higher risk of poor medication adherence than the highincome group. For the patients aged 50 and older, the low-income group and the Medical Aid beneficiaries had a higher risk of poor medication adherence compared to the high-income group. In the patient under 50 years of age, the risk for the stroke incidence of the low-income group and the Medical Aid beneficiaries were higher than those in the high-income group. In the patients aged 50 and older, all the other income groups had a significantly higher risk of incidence of stroke. Causal mediation analysis showed that the mediated effect of poor medication adherence in all groups was not significant. Conclusions: Low income significantly increased poor hypertension medication adherence and the incidence of stroke. The mediated effect of poor medication adherence was not significant.

Background Managing unilateral vertically displaced sacral fractures remains a challenge. A triangular osteosynthesis (TOS), which involves fixing the fractured sacrum using unilateral spinopelvic fixation and a supplemental ilio-sacral screw, continues to gain popularity as it facilitates early mobilization and improves the long-term outcome. However, it has limitations, such as destruction of the L5-S1 joint, the need for additional removal surgery, and an increased risk of infection due to the large incision. An S1 pediculoiliac construct was proposed to overcome this limitations. Its use also has complications, however, including a painful hardware prominence due to the traditional iliac screw, excessive soft tissue retraction, and limited reduction capability. Case Description A 20-year-old woman fell from a height of 6 meters and sustained a vertical shear type sacral fracture on the left side with substantial vertical displacement. We reduced and fixed the fracture using a TOS using an S1 pedicle screw and an S2 alar iliac screw (S2AIS). The patient was allowed immediate weight-bearing as tolerated. We achieved good reduction and union with a small vertical incision, without the destruction of L5-S1 joints, a symptomatic implant prominence, or wound complications. Conclusions For unilateral vertically unstable sacral fractures, TOS using S1 pedicle screws and S2AIS is safe and has the advantage such as maintaining mobility in the lumbar pelvic region, small size wounds, and reduced soft tissue damage, and it may have a potentially low infection rate. Further studies are needed to determine the specific indications and validate the effectiveness of this procedure.

This study investigated the characteristics of transmission routes of COVID-19 cluster infections (⩾10 linked cases within a short period) in Gangwon Province between 22 February 2020 and 31 May 2021. Transmission routes were divided into five major categories and 35 sub-categories according to the relationship between the infector and the infectee and the location of transmission. A total of 61 clusters occurred during the study period, including 1741 confirmed cases (55.7% of all confirmed cases (n = 3125)). The the five major routes of transmission were as follows: ‘using (staying in) the same facility (50.7%), ‘cohabiting family members’ (23.3%), ‘social gatherings with acquaintances’ (10.8%), ‘other transmission routes’ (7.0%), and ‘social gatherings with non-cohabiting family members/relatives’ (5.5%). For transmission caused by using (staying in) the same facility, the highest number of confirmed cases was associated with churches, followed by medical institutions (inpatient), sports facilities, military bases, offices, nightlife businesses, schools, restaurants, day-care centres and kindergarten, and service businesses. Our analysis highlights specific locations with frequent transmission of infections, and transmission routes that should be targeted in situations where adherence to disease control rules is difficult.

Study Design: Retrospective case series Objectives: Reduction of translational/angular slip is a favorable radiological result in spinal fusion for degenerative spondylolisthesis, although its clinical significance remains controversial. Few studies have investigated slip reduction and associated factors in oblique lumbar interbody fusion (OLIF) for degenerative spondylolisthesis. Methods: This study involved a retrospective analysis of 56 operated levels of 52 consecutive patients who underwent OLIF for degenerative spondylolisthesis and had more than 1-year of regular follow-up. Translational/angular slip, anterior/posterior disc height, and spinopelvic parameters were measured preoperatively, postoperatively at 6-weeks, and at the last follow-up. Demographic, radiological, and surgical parameters were analyzed to determine factors associated with the amount of slip reduction. Result: The mean follow-up duration was 30.4 ± 12.9 months (range, 12 to 61). The mean decrease in translational slip was 5.7 ± 2.1 mm (13.6 ± 5.5%) and the mean increase in angular slip was 7.9 ± 7.1° at the last follow-up (both P < 0.001). The amount of slip reduction was greater in female sex, age < 65 years, use of a 12° cage, cage position from the anterior disc margin of < 7 mm, and cases with posterior decompression (laminectomy with inferior facetectomy). Conclusions: OLIF showed satisfactory translational/angular slip reduction in degenerative spondylolisthesis. Surgical techniques for optimal reduction include the use of a large angle cage, anterior cage placement, and resection of the inferior facet.

In this work, the dynamic combustion characteristics in a scramjet engine were investigated using three diagnostic data analysis methods: DMD (Dynamic Mode Decomposition), STFT (Short-Time Fourier Transform), and CEMA (Chemical Explosive Mode Analysis). The data for the analyses were obtained through a 2D numerical experiment using a DDES (Delayed Detached Eddy Simulation) turbulence model, the UCSD (University of California at San Diego) hydrogen/oxygen chemical reaction mechanism, and high-resolution schemes. The STFT was able to detect that oscillations above 50 kHz identified as dominant in FFT results were not the dominant frequencies in a channel-type combustor. In the analysis using DMD, it was confirmed that the critical point that induced a complete change of mixing characteristics existed between an injection pressure of 0.75 MPa and 1.0 MPa. A combined diagnostic analysis that included a CEMA was performed to investigate the dynamic combustion characteristics. The differences in the reaction steps forming the flame structure under each combustor condition were identified, and, through this, it was confirmed that the pressure distribution upstream of the combustor dominated the dynamic combustion characteristics of this scramjet engine. From these processes, it was confirmed that the combined analysis method used in this paper is an effective approach to diagnose the combustion characteristics of a supersonic combustor.

Links between sagittal spinal alignment and acetabular orientation attract considerable research attention with the goal of understanding “hip-spine syndrome.” However, whether pelvic incidence (PI) is related to acetabular orientation remains debatable. The purpose of the present study was to determine 1. whether the correlation between PI and acetabular orientation is present in pelvises of young healthy adults, and 2. whether the correlation is present in subgroups of sex, or between the left and right pelvis. We analyzed 100 abdominopelvic computed tomography (CT) scans of skeletally healthy young adults. We measured PI and acetabular orientation with three-dimensional (3D) measurements. The orientation of 200 acetabula was measured using 3D reconstructed models of 100 pelvises in the coordinate system based on the anterior pelvic plane (APP). To quantify the acetabular orientation, the radiographic definitions of anteversion and inclination were used. To examine the correlation between acetabular orientation and PI, Pearson's correlation was used. The mean PI was 46.9° ± 10.2°, and the mean acetabular orientation 15.3° ± 5.7° anteverted and 37.5° ± 3.9° inclined. While no significant difference in the PI was observed, the average acetabular orientation of female pelvises (anteversion, 17.5° ± 5.6°; inclination, 36.7° ± 3.7°) was more anteverted and less inclined compared to that of male pelvises (anteversion, 13.2° ± 4.9°; inclination, 38.3° ± 3.9°, respectively; P values < .05). The correlation between PI and acetabular orientation was statistically not significant. After division of study group by sex, the linear correlation between PI and acetabular orientation was not statistically supported. The asymmetry of the acetabular orientation between the left and right sides was not significant. The linear relationship between anatomical acetabular orientation and PI was not evident in the normal population. Our finding thus proves the absence of a linear relationship between the upper and lower articular orientation of the pelvic segment and deepens the understanding of the characteristics of acetabular orientation and PI.

Objectives The purpose of this study was to estimate the mediating effect of subjective unmet healthcare needs on poor health. The mediating effect of unmet needs on health outcomes was estimated. Methods Cross-sectional research method was used to analyze Korea Health Panel data from 2011 to 2015, investigating the mediating effect for each annual dataset and lagged dependent variables. Results The magnitude of the effect of low income on poor health and the mediating effect of unmet needs were estimated using age, sex, education level, employment status, healthcare insurance status, disability, and chronic disease as control variables and selfrated health as the dependent variable. The mediating effect of unmet needs due to financial reasons was between 14.7% to 32.9% of the total marginal effect, and 7.2% to 18.7% in lagged model. Conclusions The fixed-effect logit model demonstrated that the existence of unmet needs raised the likelihood of poor self-rated health. However, only a small proportion of the effects of low income on health was mediated by unmet needs, and the results varied annually. Further studies are necessary to search for ways to explain the varying results in the Korea Health Panel data, as well as to consider a time series analysis of the mediating effect. The results of this study present the clear implication that even though it is crucial to address the unmet needs, but it is not enough to tackle the income related health inequalities.

Objective We hypothesized that major psychological stress can be a risk factor for cardiac arrest and that effects are modified by elapsed time from specific stressful events. Methods Case-control study was conducted using database for cardiac arrest and emergency department (ED) visiting. Cases included adult patients with cardiac arrest with presumed cardiac etiology. Controls were matched with sex and age and visiting day from unintentional injured patients in same ED. The occurrence of 9 major life events (MLEs) such as a divorce within 1 year was used as a proxy measure of major psychological stress. A multivariable conditional logistic regression conducted to estimate the effect of MLEs on the risk of cardiac arrest according to the elapsed time from the MLEs. Results A total of 95 patients with cardiac arrest and 95 controls were assessed. In the case group, a total of 58 MLEs occurred, while 33 MLEs occurred in the control group during the same period. Recent MLEs were associated with a higher risk of sudden cardiac arrest (AOR 2.26 [95% CI:1.01–5.03]). The AORs of cardiac arrest were 4.65 (95% CI, 1.38–15.67) and 7.02 (95% CI, 2.03–24.48) among participants experiencing MLEs within the last 0–3 months and those experiencing MLEs within the last 0–6 months, respectively. Cardiac arrest and MLEs in participants experiencing MLEs between 7 and 12 months prior showed no association (AOR 4.76 [95% CI, 0.97–18.36]). Conclusions MLEs were associated with cardiac arrest occurrence, and the effect was modified by the elapsed time from the MLEs.

Objectives To investigate concordance in the health behaviors of women and their partners according to age and to investigate whether there was a stronger correlation between the health behaviors of housewives and those of their partners than between the health behaviors of non-housewives and those of their partners. Methods We used data obtained from women participants in the 2015 Korea Community Health Survey who were living with their partners. The outcome variables were 4 health behaviors: smoking, drinking, eating salty food, and physical activity. The main independent variables were the partners’ corresponding health behaviors. We categorized age into 4 groups (19-29, 30-49, 50-64, and ≥ 65 years) and utilized multivariate logistic regression analysis, stratifying by age group. Another logistic regression analysis was stratified by whether the participant identified as a housewife. Results Data from 64 971 women older than 18 years of age were analyzed. Of the 4 health behaviors, the risk of smoking (adjusted odds ratio [aOR], 4.65; 95% confidence interval [CI], 3.93 to 5.49) was highest when the participant’s partner was also a smoker. Similar results were found for an inactive lifestyle (aOR, 2.56; 95% CI, 2.45 to 2.66), eating salty food (aOR, 2.48; 95% CI, 2.36 to 2.62); and excessive drinking (aOR, 1.89; 95% CI, 1.80 to 1.98). In comparison to non-housewives, housewives had higher odds of eating salty food. Conclusions The health behaviors of women were positively correlated with those of their partners. The magnitude of the concordance differed by age group.

Background This study was performed to evaluate the value of using ultrasound for stability assessment of isolated lateral malleolar fractures compared to simple X-ray, stress radiography, and arthroscopy. Methods This is a prospective cohort study with 25 consecutive patients who underwent an arthroscopic examination and subsequent surgery for isolated lateral malleolar ankle fractures. Before operation, simple and external rotation stress radiographs were obtained. Ultrasound was performed to assess the medial deltoid ligament prior to operation. Arthroscopic findings were used as reference standards. Sensitivity, specificity, and positive and negative predictability were calculated and compared using receiver operating characteristic (ROC) curve analysis for simple radiography, stress radiography, and ultrasound examination. Results The sensitivity and specificity of ultrasound for tears of the deep deltoid ligament were 94.74% and 66.67%, respectively. But, they were both 100% for complete tears of the ligament. ROC curve analysis showed that the ultrasound examination was significantly more accurate than simple and stress radiography. Conclusions Ultrasound could be used to assess the instability of isolated lateral malleolar fractures. Commonly used stress radiography appears to overrate the need for operative treatment.

Community-based health management policies are needed considering societal aging. We aimed to develop a transitional care model (TCM) program for patients with pneumonia, asthma, and chronic obstructive pulmonary disease. First, we conducted in-depth interviews with patients who were hospitalized, released, and readmitted for those three conditions to identify issues with the current hospitalization/discharge system and post-discharge processes. Next, we developed a new TCM program suited to the realities of the current medical environment. Interviews revealed problems including inadequate awareness of disease and health management; insufficient information exchange between patients, caregivers, and primary medical institutions; and absence/low usage of community-based care services. The investigation applying the new TCM program to patients and following up on readmission rates and life satisfaction after discharge is ongoing. Reviewing these results and conducting further studies in the future will allow improvements to the model., Graphical Abstract

We present a new algorithm for application to path synthesis of a four-bar linkage with continuous variables called the Hybrid Taguchi random coordinate search algorithm (HTRCA). The HTRCA combines two algorithms of the Taguchi method (TM) and the random coordinate search algorithm (RCA). The RCA adjusts one variable simultaneously with two directions and various step sizes in random order to escape a local minimum. Since the RCA modifies one variable at a time according to the random order, the result of the RCA is sensitive to an initial condition of variables. The TM was adopted to generate nearly optimal initial conditions. Using the TM, the approximate optimal value can be found in even multi-modal functions. Also, the TM is used with different setting values to escape a local minimum point by changing two or more variables in one step. By combining the two methods, a global optimal value can be found efficiently. Seven test functions were optimized and the robust and efficient performance was verified by comparison with other hybrid optimization algorithms. Finally, path synthesis of four-bar linkage is done by the developed optimization algorithm, and the result is compared to previous works on the same problem with evolutionary algorithm.

Recently, high-strength strands with greater yield and tensile strength than ordinary strands have been developed in several countries. However, the influences of the high-strength strands on flexural members and code provisions have not been fully identified to date. In this study, five large post-tensioned girders were tested to investigate the effect of high-strength strands on the flexural behavior based on the concrete compressive strength and the tensile strength of the strands. The test results indicated that the actual flexural behaviors showed good agreement with the predictions of the current code, regardless of the tensile strength of the strands. The specimens exhibited ductile behavior, and the crack patterns were similar in all the specimens. Certain specimens under service load exhibited crack widths and stress in the tensile reinforcements that slightly exceeded the limit in the current codes. Because the excess was not considerable, reasonable crack control can be achieved by the proper arrangement of deformed rebars. However, further study is required to create clear guidelines.

This paper presents a multi-component layout optimization method that incorporates a parametric and topology optimization method to determine the optimal configuration of a permanent magnet actuator (PMA). The optimal position and size of the rectangular-type PM are obtained by the design sensitivities of size parameters. The level set-based topology optimization method, which can guarantee a high degree of freedom in geometrical change, is employed to obtain the optimal distribution of the ferromagnetic material (FM) that can affect the path of the magnetic flux. The optimization problem is formulated to maximize the magnetic force of the PMA under the fixed volume fraction constraint of each material. The magnetic properties of the PM and FM, such as the magnetic relative reluctivity and the direction of the remanent magnetic flux, are calculated by the geometric parameters and the sign of the level set function. To confirm the effectiveness of the proposed method, a design example of a simple C-core actuator is provided.

This paper proposes a new level-set-based topology optimization method for magnetic actuator design using remeshing techniques that can generate meshes on the exact structural boundaries to improve the accuracy of finite-element analysis. Two remeshing techniques, such as the modified adaptive mesh method and the extended finite-element method (XFEM), are introduced for the optimization process. To control the computational time with meshing that is economical and analysis that is accurate, a new resolution parameter that can manage the level of mesh density around the level-set boundaries is employed in the modified adaptive mesh method. In the XFEM, the enrichment term in the element shape function is employed to track the exact outer boundary of the actuator. The optimization problem is formulated to maximize the magnetic force between the core and an armature under the volume constraint of the ferromagnetic material. To verify the effectiveness of the proposed method, it is applied to an electromagnetic problem for an optimal C-core actuator design that is very sensitive to structural boundaries.

We investigated whether income level has long-term effects on mortality rate in stroke patients and whether this varies with time after the first stroke event, using the National Health Insurance Service National Sample Cohort data from 2002 to 2015 in South Korea. The study population was new-onset stroke patients &ge, 18 years of age. Patients were categorized into Category (1) insured employees and Category (2) insured self-employed/Medical Aid beneficiaries. Each category was divided into three and four income level groups, retrospectively. The study population comprised of 11,668 patients. Among the Category 1 patients (n = 7720), the low-income group&rsquo, s post-stroke mortality was 1.15-fold higher than the high-income group. Among the Category 2 patients (n = 3948), the lower income groups had higher post-stroke mortality than the high-income group (middle-income, aOR (adjusted odds ratio) 1.29, low-income, aOR 1.70, Medical Aid beneficiaries, aOR 2.19). In this category, the lower income groups&rsquo, post-stroke mortality risks compared to the high-income group were highest at 13&ndash, 36 months after the first stroke event(middle-income, aOR 1.52, low-income, aOR 2.31, Medical Aid beneficiaries, aOR 2.53). Medical Aid beneficiaries had a significantly higher post-stroke mortality risk than the high-income group at all time points.

Background Adrenal insufficiency (AI) is associated with high morbidity and mortality. The aim of this systematic review was to enhance diagnostic approaches and summarize therapeutic strategies in the management of AI in patients with systematic lupus erythematosus (SLE) or antiphospholipid syndrome (APS). Methods A literature search of PubMed and Medline databases was performed and 91 publications containing 105 cases were included for the final analysis. Results The following frequency of clinical signs and symptoms was noted: abdominal pain (39.04%) was the leading symptom, followed by fever (33.33%), vomiting (23.81%), and nausea (19.05%). APS was present in 73%, SLE in 17% of the patients, while 2% had a diagnosis of both, SLE and APS. ACTH stimulation test (ACTHst) was performed in 18% of cases and 76.6% of them were unresponsive towards stimulation. Variable treatment approaches were used: hydrocortisone was most commonly used (38.09%), followed by fludrocortisone (26.67%), prednisolone (20.00%) and volume replacement treatment (11.43%), respectively. Conclusions This analysis highlights the importance of an early diagnosis and initiation of therapeutic management when AI is suspected. In line, signs and symptoms related to autoimmune diseases in patients with AI should be reviewed crtitically.

A wireless charging or inductive charging electric vehicle (EV) is a type of EVs with a battery that is charged from a charging infrastructure, using a wireless power transfer technology. Wireless charging EVs are classified as stationary or dynamic charging EVs. Stationary charging EVs charge wirelessly when they are parked, and dynamic charging EVs can charge while they are in motion. The online electric vehicle developed at the Korea Advanced Institute of Science and Technology is an example of a commercially available dynamic charging transportation system. Numerous studies have reported that one of the benefits of dynamic charging is that it allows smaller and lighter batteries to be used, due to frequent charging using the charging infrastructure embedded under roads. In this paper, we quantitatively analyze the benefits of dynamic charging with an economic model of battery size and charging infrastructure allocation, using a mathematical optimization model. Particularly, we analyze by how much battery size can be reduced and what the cost saving of reducing the battery size is with the model. We also show that the dynamic charging can be beneficial to battery life.

Background The purpose of this study was to identify the characteristics of injuries of school-aged children transported via emergency medical services (EMS) that occurred in schools by comparing with injuries that occurred outside of school. Methods Data from the 119 EMS from 2012 to 2014 were analyzed. School and non-school injuries were analyzed in children 6 to 17 years of age. The epidemiologic characteristics were assessed according to school-age groups; low-grade primary (6–8 years), high-grade primary (9–13 years), middle (13–15 years) and high (15–17 years) school. Gender-stratified multivariable logistic regression analysis was conducted to estimate the risks of school injury in each age group. Results During the study period, a total of 167,104 children with injury were transported via 119 ambulances. Of these injuries, 13.3% occurred at schools. Boys accounted for 76.9% of school injuries and middle school children accounted for a significantly greater proportion (39.6%) of school injuries (P < 0.001). The most frequent mechanisms of injury at school were falls (43.8%). The peak times for school injury occurrence were lunch time (13:00–13:59) in all age groups. Multivariate regression identified the risky age groups as high-grade primary (odds ratio [OR], 1.14; 95% confidence interval [CI], 1.09–1.20) and middle school-aged boys (OR, 1.82; 95% CI, 1.74–1.90) and middle school-aged girls (OR, 1.30; 95% CI, 1.21–1.40). Conclusion Notable epidemiologic differences exist between in- and out-of-school injuries. The age groups at risk for school injuries differ by gender., Graphical Abstract

OBJECTIVES This study examined differences in health behaviors between elderly people living alone and with others; it also investigated whether the effect of living with others differs according to housemate type, namely a spouse and/or younger generations. METHODS Gender-stratified data from the 2013 Korea Community Health Survey for individuals aged 60 to 74 living in Seoul were analyzed. Logistic regression modeling was conducted to obtain odds ratios (ORs) and 95% confidence intervals (CIs) of the outcome variables (smoking, drinking, eating salty foods, inactive lifestyle) for the variables of interest (living alone/with others, housemate type). Models were adjusted for confounding variables including history of medical conditions, employment type, and adjusted household income. RESULTS Analysis involved 1,814 men and 2,199 women. Risk of smoking was 1.80 times (95% CI, 1.21 to 2.67) higher for men living alone than living with others. Risk of eating salty foods was 0.78 times lower (95% CI, 0.62 to 0.98) for men living with a spouse than a spouse and younger generations. Risk of inactive lifestyle was 1.47 times higher (95% CI, 1.13 to 1.92) for women living alone. Risk of smoking was higher for women living alone (OR, 1.41; 95% CI, 1.03 to 1.92) or with younger generations (OR, 9.12; 95% CI, 2.04 to 40.80) than with a spouse and younger generations. CONCLUSIONS Living alone was associated with smoking in men and physical activity in women; housemate type was associated with dietary habits in men and smoking in women. These gender-specific findings can help identify groups of individuals vulnerable to risky health behaviors and to develop policies.

In this paper, we first present an in-depth survey of the research on Verification, Validation and Accreditation (VV&A) applied in various areas. Then we introduce the characteristics of the military and defense Modeling and Simulation (M&S) and propose the direction of method for VV&A with the identified characteristics. The M&S has been widely used in many different applications in the military and defense area including training, analysis, and acquisition. Methods and processes of VV&A have been proposed by researchers and M&S practitioners to guarantee the correctness of the M&S. The idea of applying the formal credibility assessment in VV&A is originated from the Software Engineering Reliability Test and Systems Engineering Development Process. However, the current VV&A techniques and processes proposed in the research community have not utilized the military-and-defense specific characteristics. We identify the characteristics and issues that can be found in the military and defense M&S. Then propose the direction of techniques and methods for VV&A considering the characteristics and issues. Also, possible research direction on the development of VV&A is proposed.

In this paper, we provide the numerical analysis of the charging states for the dynamic wireless charging (DWC) electric vehicles (EVs), or simply called DWC-EVs, which charge the their batteries from the power source embedded under the road while the vehicles are in motion. The previous studies suggested the optimal allocation of the wireless power source called power track and economic size of the battery. However, these studies used the assumption that the vehicles are driving with a predetermined speed. This study relaxes the nominal speed assumption and instead assumes that the uncertainty in the vehicle speed. The goal of this study is to understand the how the uncertainty in driving causes the performance of the charging and operation of the vehicles for the DWC-EV based public transportation system. In this study, we used the operation data collected from the KAIST On-line Electric Vehicle (OLEV) currently operating in a Gumi City in South Korea, which is one of the first commercialized DWC-EVs. With the data, energy states are generated from the Markov-based energy consumption simulation model. The simulation results indicate that there is significant risk of running out of battery if the power tracks are allocated and battery size is selected with the nominal speed assumption.

It is unclear whether the atmosphere temperature is associated with outcomes after out-of-hospital cardiac arrest (OHCA).This is a nationwide observational study using the national OHCA registry merged with a geographical and weather database. Adult patients with a cardiac etiology that occurred from 2006 to 2013 were included, excluding patients with unknown outcome or unknown weather information. The main exposure was the hourly measured temperature matched to the OHCA event time. The covariates were age, gender, metropolis, place, and weather factors (wind speed and humidity). The primary outcome was good cerebral performance scale (CPC) 1 or 2. Patients were classified with three temperature groups by quartile range: Cold (4°C), Intermediate (4-21°C), and Hot (≥22°C). We tested the associations between the atmosphere temperature (by 1°C and by temperature group) and outcomes using multivariable logistic regression analysis.Of 17,3051 OHCAs, a total of 115,578 cases were matched to weather database. A total of 78,717 OHCAs were analyzed. The proportion of good CPC 1 or 2 was 1.7% in the Cold group, 1.8% in the Intermediate group, and 2.3% in the Hot group. As the temperature at the event of OHCA increased by 1°C, AORs (95% CIs) were 1.006 (1.002-1.009) for good CPC. The AORs (95% CIs) for good CPC in Cold and Hot group comparing with Intermediate group for good CPC were 0.964 (0.845-1.100) and 1.246 (1.096-1.416), respectively.The temperature at the time of the OHCA event was associated with outcomes after OHCA in a nationwide observational study in Korea.

Objective The objective of this meta-analysis was to compare the benefits of prehospital advanced airway management (AAM) and basic airway management (BAM) for out-of-hospital cardiac arrest (OHCA) patients. Methods Two investigators performed a systematic review of PubMed, EMBASE, and the Cochrane Database to identify all peer-reviewed articles relevant to this meta-analysis. We included all articles describing emergency medical system–treated nontraumatic OHCAs; specifically, all articles that described intervention of the prehospital AAM type were considered. The primary outcome was survival to discharge, whereas the secondary outcome was neurologic recovery after an OHCA event. For subgroup analysis, we compared the clinical outcome of endotracheal intubation (ETI), a specific type of AAM, vs BAM. Results We reviewed 1452 studies, 10 of which satisfied all the inclusion criteria and involved 17 380 patients subjected to AAM and 67 525 subjected to BAM. Based on the full random effects model, patients who received AAM had lower odds of survival (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.29-0.90) compared with BAM. Subgroup analysis for ETI vs BAM showed no significant association with respect to survival (OR, 0.44; 95% CI, 0.16-1.23). There were no significant differences in the odds of neurologic recovery between AAM and BAM (OR, 0.64; 95% CI, 0.03-1.37). Conclusions Our results reveal decreased survival odds for OHCA patients treated with AAM by emergency medical service personnel compared with BAM. However, the role of prehospital AAM, especially ETI, on achieving neurologic recovery remains unclear.