Predicted Cervical Cancer Prevention: Impact of National HPV Vaccination Program on Young Women in South Korea

PURPOSE

This study aimed to evaluate the effectiveness of the national human papillomavirus (HPV) vaccination program of South Korea among its entire female population, particularly among younger age groups.

MATERIALS AND METHODS

We first predicted the incidence of cervical cancer over the next 20 years (2021-2040) using the Nordpred package based on Møller's age-period-cohort model under several scenarios for the national HPV vaccination program. We calculated the potential impact fractions and proportional differences under the current national vaccination programs, and alternative scenarios using the no-vaccination assumption as a reference.

RESULTS

We estimated that the current national vaccination program would prevent 4.13% of cervical cancer cases and reduce the age-standardized incidence rate (ASR) by 8.79% in the overall population by 2036-2040. Under the alternative scenario of implementing the nine-valent vaccine, 5.13% of cervical cancer cases could be prevented and the ASR reduced by 10.93% during the same period. In another scenario, expanding the vaccination age to 9-17 years could prevent 10.19% of cervical cancer cases, with the ASR reduced by 18.57% during the same period. When restricted to ages < 40 years, the prevention effect was remarkably greater. We predict that the current national HPV program will reduce its incidence by more than 30% between 2036 and 2040 in women aged < 40 years.

CONCLUSION

The effectiveness of the vaccination program in reducing the incidence of cervical cancer was confirmed, with a considerable impact anticipated in younger age groups.

Role of invasive mediastinal nodal staging in survival outcomes of patients with non-small cell lung cancer and without radiologic lymph node metastasis: a retrospective cohort study

Background

Lung cancer diagnostic guidelines advocate for invasive mediastinal nodal staging (IMNS), but the survival benefits of this approach in patients with non-small cell lung cancer (NSCLC) without radiologic evidence of lymph node metastasis (rN0) remain uncertain. We aimed to investigate the impact of IMNS in patients with rN0 NSCLC by comparing the long-term survival between patients who underwent IMNS and those who did not (non-IMNS).

Methods

In this retrospective cohort study, we included patients with NSCLC but without radiologic evidence of lymph node metastasis from the Registry for Thoracic Cancer Surgery and the clinical data warehouse at the Samsung Medical Centre, Republic of Korea between January 2, 2008 and December 31, 2016. We compared the 5-year overall survival (OS) rate as the primary outcome after propensity score matching between the IMNS and non-IMNS groups. The age, sex, performance statue, tumor size, centrality, solidity, lung function, FDG uptake in PET-CT, and histological examination of the tumor before surgery were matched.

Findings

A total of 4545 patients (887 in the IMNS group and 3658 in the non-IMNS group) who received curative treatment for NSCLC were included in this study. By the mediastinal node dissection, the overall incidence of unforeseen mediastinal node metastasis (N2) was 7.2% (317/4378 patients). Despite the IMNS, 67% of pathological N2 was missed (61/91 patients with unforeseen N2). Based on propensity score matching, 866 patients each for the IMNS and non-IMNS groups were assigned. There was no significant difference in 5-year OS and recurrence-free survival (RFS) between two groups: 5-year OS was 73.9% (95% confidence interval, CI: 71%-77%) for IMNS and 71.7% (95% CI: 68.6%-74.9%; p = 0.23), for non-IMNS (hazard ratio, HR 0.90, 95% CI: 0.77-1.07), while 5-year RFS was 64.7% (95% CI: 61.5%-68.2%) and 67.5% (95% CI: 64.3%-70.9%; p = 0.35 (HR 1.08, 95% CI: 0.92-1.27), respectively. Moreover, the timing and locations of recurrence were similar in both groups.

Interpretation

IMNS might not be required before surgery for patients with NSCLC without LN suspicious of metastasis. Further randomised trials are required to validate the findings of the present study.

Funding

None.

Utilization of the Unlinked Case Proportion to Control COVID-19: A Focus on the Non-pharmaceutical Interventional Policies of the Korea and Japan

OBJECTIVES

Korea and Japan have managed the spread of coronavirus disease 2019 (COVID-19) using markedly different policies, referred to as the "3T" and "3C" strategies, respectively. This study examined these differences to assess the roles of active testing and contact tracing as non-pharmaceutical interventions (NPIs). We compared the proportion of unlinked cases (UCs) and test positivity rate (TPR) as indicators of tracing and testing capacities.

METHODS

We outlined the evolution of NPI policies and investigated temporal trends in their correlations with UCs, confirmed cases, and TPR prior to the Omicron peak. Spearman correlation coefficients were reported between the proportion of UCs, confirmed cases, and TPR. The Fisher r-to-z transformation was employed to examine the significance of differences between correlation coefficients.

RESULTS

The proportion of UCs was significantly correlated with confirmed cases (r=0.995, p<0.001) and TPR (r=0.659, p<0.001) in Korea and with confirmed cases (r=0.437, p<0.001) and TPR (r=0.429, p<0.001) in Japan. The Fisher r-to-z test revealed significant differences in correlation coefficients between the proportion of UCs and confirmed cases (z=16.07, p<0.001) and between the proportion of UCs and TPR (z=2.12, p=0.034) in Korea and Japan.

CONCLUSIONS

Higher UCs were associated with increases in confirmed cases and TPR, indicating the importance of combining testing and contact tracing in controlling COVID-19. The implementation of stricter policies led to stronger correlations between these indicators. The proportion of UCs and TPR effectively indicated the effectiveness of NPIs. If the proportion of UCs shows an upward trend, more testing and contact tracing may be required.

Annual Endovascular Thrombectomy Case Volume and Thrombectomy-capable Hospitals of Korea in Acute Stroke Care

Objectives: Although it is difficult to define the quality of stroke care, acute ischemic stroke (AIS) patients with moderate-to-severe neurological deficits may benefit from thrombectomy-capable hospitals (TCHs) that have a stroke unit, stroke specialists, and a substantial endovascular thrombectomy (EVT) case volume.Methods: From national audit data collected between 2013 and 2016, potential EVT candidates arriving within 24 hours with a baseline National Institutes of Health Stroke Scale score ≥6 were identified. Hospitals were classified as TCHs (≥15 EVT case/y, stroke unit, and stroke specialists), primary stroke hospitals (PSHs) without EVT (PSHs-without-EVT, 0 case/y), and PSHs-with-EVT. Thirty-day and 1-year case-fatality rates (CFRs) were analyzed using random intercept multilevel logistic regression.Results: Out of 35 004 AIS patients, 7954 (22.7%) EVT candidates were included in this study. The average 30-day CFR was 16.3% in PSHs-without-EVT, 14.8% in PSHs-with-EVT, and 11.0% in TCHs. The average 1-year CFR was 37.5% in PSHs-without-EVT, 31.3% in PSHs-with-EVT, and 26.2% in TCHs. In TCHs, a significant reduction was not found in the 30-day CFR (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.76 to 1.12), but was found in the 1-year CFR (OR, 0.84; 95% CI, 0.73 to 0.96).Conclusions: The 1-year CFR was significantly reduced when EVT candidates were treated at TCHs. TCHs are not defined based solely on the number of EVTs, but also based on the presence of a stroke unit and stroke specialists. This supports the need for TCH certification in Korea and suggests that annual EVT case volume could be used to qualify TCHs.

Racial and Ethnic Differences in the Association of Low-Carbohydrate Diet With Mortality in the Multi-Ethnic Study of Atherosclerosis

IMPORTANCE

Evidence linking low-carbohydrate diets (LCDs) to mortality is limited among multiethnic populations.

OBJECTIVE

To evaluate the association between LCDs and mortality by race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

The Multi-Ethnic Study of Atherosclerosis is a large, population-based prospective cohort study of adults aged 45 to 84 years recruited from 6 US communities. A total of 6109 participants without baseline cardiovascular disease were included in this analysis. Baseline data were collected from July 2000 to August 2002, with follow-up completed by December 2017. The data were analyzed between May 2021 and April 2022.

EXPOSURES

Food frequency questionnaires were used to assess dietary intake. From these data, overall LCD scores were calculated from the percentages of energy intake from carbohydrates, fats, and proteins. Animal-based (emphasizing saturated fat and animal protein) and vegetable-based (emphasizing monounsaturated fat and vegetable protein) LCD scores were also calculated.

MAIN OUTCOMES AND MEASURES

All-cause and cause-specific mortality over a median follow-up of 15.9 years (IQR, 14.3-16.6 years).

RESULTS

Among the 6109 participants (mean [SD] age, 62.3 [10.3] years; 3190 women [52.2%]; 1623 African American [26.6%], 701 Chinese American [11.5%], 1350 Hispanic [22.1%], and 2435 non-Hispanic White [39.8%]), there were 1391 deaths. Overall, LCD scores were not associated with mortality, but when analyses were stratified by race and ethnicity, a lower risk of all-cause and non-CV mortality was observed among Hispanic participants with moderate carbohydrate intake. Specifically, the hazard ratios for total mortality for overall LCD scores were 0.58 (95% CI, 0.40-0.84) for quintile 2, 0.67 (95% CI, 0.45-0.98) for quintile 3, 0.60 (95% CI, 0.41-0.87) for quintile 4, and 0.83 (95% CI, 0.57-1.21) for quintile 5, with quintile 1 as the reference group. A similar association was observed for animal-based (but not vegetable-based) LCD scores. In contrast, no significant associations were found between LCD scores and mortality risk in the other racial and ethnic groups.

CONCLUSIONS AND RELEVANCE

In this cohort study of multiethnic US adults, LCD score was not associated with mortality in the whole population. However, moderate carbohydrate intake was associated with a lower risk of mortality among Hispanic participants. These findings suggest that the association between carbohydrate intake and mortality may differ according to race and ethnicity. Dietary guidelines considering these differences may be necessary.

The Impact of Household Economic Deterioration Caused by the COVID-19 Pandemic and Socioeconomic Status on Suicidal Behaviors in Adolescents: A Cross-sectional Study Using 2020 Korea Youth Risk Behavior Web-based Survey Data

OBJECTIVES

Economic hardship has a serious impact on adolescents' mental health. The financial impact of the coronavirus disease 2019 (COVID-19) pandemic was more severe for low-income families, and this also impacted adolescents. This study aimed to examine the associations of economic deterioration (ED) caused by the COVID-19 pandemic and low socioeconomic status (SES) with adolescents' suicidal behaviors.

METHODS

This study analyzed data from the 2020 Korea Youth Risk Behavior Web-based Survey, which included 54 948 middle and high school students. Odds ratios (ORs) of suicidal ideation, suicidal planning, and suicide attempts related to ED and SES were calculated using multivariable logistic regression. We calculated relative excess risks due to interaction to assess additive interactions.

RESULTS

The ORs for suicidal ideation, suicidal planning, and suicide attempts related to combined severe ED and low SES were 3.64 (95% confidence interval [CI], 3.13 to 4.23), 3.88 (95% CI, 3.09 to 4.88), and 4.27 (95% CI, 3.21 to 5.69), respectively.

CONCLUSIONS

ED and low SES were significantly associated with suicidal behaviors in adolescents. Although no significant additive interaction was found, the ORs related to suicidal ideation, suicidal planning, and suicide attempts were highest among adolescents from low-income families with severe ED. Special attention is needed for this group, considering the increased impact of economic inequality due to the COVID-19 pandemic.

Resting-State Brain Variability in Youth With Attention-Deficit/Hyperactivity Disorder

In this study, we sought to determine the nature of the abnormality in resting-state default mode network (DMN) activation and explore its correlation with functional connectivity in attention-deficit/hyperactivity disorder (ADHD). We obtained resting-state functional magnetic resonance images of youth with ADHD and typically developing counterparts from the publicly available ADHD-200 database. We used data from Peking University (232 scans) and New York University (172 scans); the scan repetition time was 2 s for both data collection sites. We applied generalized estimating equations to estimate the variability of the averaged blood-oxygen-level-dependent (BOLD) time series extracted from the DMN at rest. We performed network-based statistics to determine the association between the observed differences in BOLD signal variability and altered functional connectivity. We analyzed data from 105 youth with ADHD (age: mean 12.17, standard deviation 2.31, median 12.25; 15.2% female, 84.8% male) and 140 typically developing youth (age: mean 11.99, standard deviation 2.28, median 11.85; 47.1% female, 52.9% male), who aged 7-17 years. The imaging data were cross-sectionally collected for each participant at one time point. We observed a greater number of significant BOLD signal changes and higher-order polynomial significant associations in youth with ADHD. Moreover, there were significant between-group differences in BOLD signal change after the first 140 s, which coincided with decreased resting-state functional connectivity within the DMN in youth with ADHD. Increased variability of neural signaling was intermittently observed in the brains of youth with ADHD at rest, thereby indicating their default mode state was more unstable than that of typically developing youth.

Epidemiological and spatio-temporal characteristics of COVID-19 in Rwanda

BACKGROUND

The coronavirus disease 2019 (COVID-19) has taken millions of lives and disrupted living standards at individual, societal, and worldwide levels, causing serious consequences globally. Understanding its epidemic curve and spatio-temporal dynamics is crucial for the development of effective public health plans and responses and the allocation of resources. Thus, we conducted this study to assess the epidemiological dynamics and spatio-temporal patterns of the COVID-19 pandemic in Rwanda.

METHODS

Using the surveillance package in R software version 4.0.2, we implemented endemic-epidemic multivariate time series models for infectious diseases to analyze COVID-19 data reported by Rwanda Biomedical Center under the Ministry of Health from March 15, 2020 to January 15, 2021.

RESULTS

The COVID-19 pandemic occurred in two waves in Rwanda and showed a heterogenous spatial distribution across districts. The Rwandan government responded effectively and efficiently through the implementation of various health measures and intervention policies to drastically reduce the transmission of the disease. Analysis of the three components of the model showed that the most affected districts displayed epidemic components within the area, whereas the effect of epidemic components from spatial neighbors were experienced by the districts that surround the most affected districts. The infection followed the disease endemic trend in other districts.

CONCLUSION

The epidemiological and spatio-temporal dynamics of COVID-19 in Rwanda show that the implementation of measures and interventions contributed significantly to the decrease in COVID-19 transmission within and between districts. This accentuates the critical call for continued intra- and inter- organization and community engagement nationwide to ensure effective and efficient response to the pandemic.

The Association between Community Water Fluoridation and Bone Diseases: A Natural Experiment in Cheongju, Korea

The present study aimed to investigate the association between bone diseases and community water fluoridation (CWF). An ecological study with a natural experiment design was conducted in Cheongju, South Korea, from 1 January 2004 to 31 December 2013. The community water fluoridation program was implemented in Cheongju and divided into CWF and non-CWF areas. To observe adverse health effects related to bone diseases, we conducted a spatio-temporal analysis of the prevalence of hip fracture, osteoporosis, and bone cancer in residents who have lived in CWF and non-CWF areas using National Health Insurance Service data. First, we used standardized incidence ratios to estimate the disease risk. Second, the hierarchical Bayesian Poisson spatio-temporal regression model was used to investigate the association between the selected bone diseases and CWF considering space and time interaction. The method for Bayesian estimation was based on the R-integrated nested Laplace approximation (INLA). Comparing the CWF area with the non-CWF area, there was no clear evidence that exposure to CWF increased health risks at the town level in Cheongju since CWF was terminated after 2004. The posterior relative risks (RR) of hip fracture was 0.95 (95% confidence intervals 0.87, 1.05) and osteoporosis was 0.94 (0.87, 1.02). The RR in bone cancer was a little high because the sample size very small compared to the other bone diseases (RR = 1.20 (0.89, 1.61)). The relative risk of selected bone diseases (hip fractures, osteoporosis, and bone cancer) increased over time but did not increase in the CWF area compared to non-CWF areas. CWF has been used to reduce dental caries in all population groups and is known for its cost-effectiveness. These findings suggest that CWF is not associated with adverse health risks related to bone diseases. This study provides scientific evidence based on a natural experiment design. It is necessary to continue research on the well-designed epidemiological studies and develop public health prevention programs to help in make suitable polices.

Melt processing of polypropylene-grafted-maleic anhydride/Chitosan polymer blend functionalized with montmorillonite for the removal of lead ions from aqueous solutions

Heavy metals such as lead ions Pb (II) are a primary concern in the aquatic environment. These is because Pb (II) is poisonous at a threshold limit above 0.01 mg/L, when consumed over a long period of time. Pb (II) poisoning is very harmful to various organs viz. heart, intestine and kidneys. Besides, it affects bones, tissues, nervous and reproductive systems. Hence, it is important to remove Pb (II) from aquatic environment. Polypropylene (PP) and polypropylene grafted-maleic-anhydride (PP-g-MA) based nanocomposites reinforced with Chitosan (CS) and modified montmorillonite clay nanofiller (CL120DT) were successfully fabricated using twin screw melt extrusion for adsorption of Pb (II). The resulting nanocomposites were characterized by XRD to analyze the dispersion properties of the material, TEM and SEM for surface morphology, FTIR analysis for the functional groups and TGA for thermal stability. Pure PP showed two sharp peaks, but there was decreased in the intensity upon adding of CS and CL120DT. Among series of nanocomposites 2.0 phr and 4.0 phr loaded samples shows better storage module than that of pure PP. The uptake of Pb (II) from lead nitrate aqueous solution by PP + PP-g-MA/CL120DT-CS 2.0 phr nanocomposites followed the Langmuir isotherm model, with a remediation of 90.9% at pH 8 and was verified by pseudo-second order kinetic model. These results indicate that PP + PP-g-MA//CL120DT-CS 2.0 phr nanocomposites performed as a superabsorbent for the Pb (II) ion removal from aqueous solution.

Real-world treatment patterns of renal anemia in hemodialysis patients: A multicenter cohort study performed using DialysisNet (RRAHD study)

A multicenter cohort study.The DialysisNet was previously developed for the management of hemodialysis (HD) patients based on the American Society for Testing and Materials Continuity of Care Records by metadata transformation. DialysisNet is a dialysis patient management program created by using the personal health record care platform to overcome the problems of registry studies, in real-time.Here, we aimed to investigate the pattern of treatment for renal anemia in HD patients using DialysisNet.We performed a multicenter cohort study among HD patients who were treated at one of the three Korean university-affiliated hospitals from January 2016 to December 2016. Subjects were divided into 4 hemoglobin variability groups by quartiles. The variable anemia treatment pattern was reviewed. To determine renal anemia treatment patterns, we automatically collected information on the practice of anemia treatment patterns such as erythropoietin stimulating agent (ESA) doses and administration frequencies, and targeted hemoglobin maintenance rate. Individual hemoglobin variabilities were expressed as (standard deviations)/(√(n/[n-1]).The records of 159 patients were analyzed (Hospital A: 35, Hospital B: 21, Hospital C: 103). Mean patients' age was 65.6 ± 12.8 years, and 61.6% were men. Overall, hemoglobin level was 10.5[7.43;13.93] g/dL. 158 (99.3%) patients were using ESA; and overall, the epoetin alfa dose was 33,000[4000;136,800] U per week. Hemoglobin levels (P = .206) and epoetin alfa doses were similar (P = .924) for patients with different hemoglobin variabilities. The hemoglobin target maintenance rate was lower in the highest hemoglobin variability group than in the lowest variability group (P = .045).In this study, detailed information on the actual anemia treatment patterns were obtained using the DialysisNet. We expect that DialysisNet will simplify and improve the renal anemia management for both dialysis patients and health care providers.

Effect of National Implementation of Telephone CPR Program to Improve Outcomes from Out-of-Hospital Cardiac Arrest: an Interrupted Time-Series Analysis

BACKGROUND

In cardiac arrest, the survival rate increases with the provision of bystander cardiopulmonary resuscitation (CPR), of which the initial response and treatment are critical. Telephone CPR is among the effective methods that might increase the provision of bystander CPR. This study aimed to describe and examine the improvement of neurological outcomes in individuals with out-of-hospital acute cardiac arrest by implementing the nationwide, standardized telephone CPR program.

METHODS

Data from the emergency medical service-based cardiac arrest registry that were collected between 2009 and 2014 were used. The effectiveness of the intervention in the interrupted time-series study was determined via a segmented regression analysis, which showed the risk ratio and risk difference in good neurological outcomes before and after the intervention.

RESULTS

Of 164,221 patients, 148,403 were analyzed. However, patients with unknown sex and limited data on treatment outcomes were excluded. Approximately 64.3% patients were men, with an average age of 63.7 years. The number of bystander CPR increased by 3.3 times (95% confidence interval [CI], 3.1-3.5) after the intervention, whereas the rate of good neurological outcomes increased by 2.6 times (95% CI, 2.3-2.9 [1.6%]; 1.4-1.7). The excess number was identified based on the differences between the observed and predicted trends. In total, 2,127 cases of out-of-hospital cardiac arrest (OHCA) after the intervention period received additional bystander CPR, and 339 cases of OHCA had good neurological outcomes.

CONCLUSION

The nationwide implementation of the standardized telephone CPR program increased the number of bystander CPR and improved good neurological outcomes.

Do police officers and firefighters have a higher risk of disease than other public officers? A 13-year nationwide cohort study in South Korea

OBJECTIVES

The work of public officers involves repeated and long-term exposure to heavy workloads, high job strain and workplace violence, all of which negatively impact physical and mental health. This study aimed to evaluate and compare the incidences of diseases among different categories of public officers in Korea, in order to further understand the health risks associated with these occupations.

DESIGN

A cohort study using the National Health Insurance data.

PARTICIPANTS

We collated claims data between 2002 and 2014 for 860 221 public officers.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-standardised rates were calculated using the direct standardisation method, and HRs were calculated using the Cox proportional hazard regression models.

RESULTS

Overall, we found that police officers and firefighters had a higher incidence of a range of diseases when compared with national and regional government officers (NRG). The most prominent HRs were observed among police officers for angina pectoris (HR: 1.52, 95% CI 1.49 to 1.54), acute myocardial infarction (HR: 1.84, 95% CI 1.77 to 1.92) and cerebrovascular disease (HR: 1.36, 95% CI 1.31 to 1.40). Firefighters were more susceptible to physical ailments and were at a significantly higher risk for traumatic stress disorders (HR: 1.40, 95% CI 1.26 to 1.56) than NRGs.

CONCLUSION

Compared withNRGs, police officers had higher HRs for all measured diseases, except for traumatic stress disorders. While firefighters had higher HRs for almost all diseases examined, public education officers had a higher HR for traumatic stress disorders, when compared with NRGs.

Estimated future incidence of malignant mesothelioma in South Korea: Projection from 2014 to 2033

Malignant mesothelioma is a malignant tumor on the pleura or the peritoneum caused mostly by asbestos. Although asbestos is not currently used in South Korea, the incidence of mesothelioma is increasing due to its long latent period. This study predicted the incidence of malignant mesothelioma in South Korea over the next 20 years using an age-period-cohort (APC) model. Data regarding mesothelioma incidence from 1994–2013 were acquired from the Korea Central Cancer Registry (KCCR). Demographic data, including prospective resident data, were acquired from the Korean Statistical Information Service (KOSIS) for 1994–2033. An APC model with Møller’s power-link function was utilized to predict the incidence of mesothelioma. It was predicted that 2,380 and 1,199 new cases of mesothelioma in men and women, respectively, would occur over the next 20 years. For both sexes, the mesothelioma incidence rate was predicted to be greater in 2029–2033 compared to that in 2009–2013 (men, 0.282 vs 0.563; women, 0.155 vs 0.217). For men, the age-standardized incidence rate was predicted to be slightly greater in 2029–2033 relative to the rate in 2009–2013 (0.228 vs 0.235), while the age-standardized incidence rate in women decreased within the same timeframe (0.113 vs 0.109). The changes in mesothelioma incidence were mostly caused by changes in the population structure due to aging and not by changes in the mesothelioma risk ratio. The results of this study project a continuous increase in mesothelioma incidence in South Korea over the next 20 years. Although the projected increase in mesothelioma incidence was not related to an increase in the mesothelioma risk ratio, continuous preventive efforts are necessary to reduce the exposure to asbestos and prevent the trend from worsening.

Supine sleep positioning in preterm and term infants after hospital discharge from 2000 to 2011

OBJECTIVE

Supine sleep positioning (SSP) has been shown to reduce the risk of sudden infant death syndrome (SIDS) and preterm infants are at higher risk for SIDS. Population-based estimates of SSP are lacking for the preterm population. The objectives of this study are: (1) compare the prevalence of SSP after hospital discharge for preterm and term infants in the United States; and (2) assess racial/ethnic disparities in SSP for preterm and term infants.

STUDY DESIGN

We analyzed the 2000 to 2011 data from the Pregnancy Risk Assessment Monitoring System of Centers for Disease Control and Prevention from 35 states. We measured prevalence of SSP by preterm and term gestational age (GA) categories. We calculated adjusted prevalence ratios (APR) to evaluate the likelihood of SSP for each GA category compared with term infants and the likelihood of SSP for non-Hispanic black (NHB) and Hispanic infants compared with non-Hispanic white (NHW) infants.

RESULTS

Prevalence of SSP varied by GA: ⩽27, 59.7%; 28 0/7 to 33 6/7, 63.7%; 34 0/7 to 36 6/7 (late preterm), 63.6%; and 37 0/7 to 42 6/7 (term) weeks, 66.8% (P<0.001). In the adjusted analyses, late preterm infants were slightly less likely to be placed in SSP compared with term infants (APR: 0.96, confidence interval: 0.95 to 0.98). There were racial/ethnic disparities in SSP for all GA categories when NHB and Hispanic infants were compared with NHW infants.

CONCLUSIONS

All infants had suboptimal adherence to SSP indicating a continued need to better engage families about SSP. Parents of late preterm infants and families of NHB and Hispanic infants will also require greater attention given their decreased likelihood of SSP.

Diastolic Dysfunction and Outcome in Acute Ischemic Stroke

Background: Left ventricular diastolic dysfunction (DD) is associated with an increased mortality in general population and patients with myocardial infarct. In the present study, we investigated whether DD is associated with outcomes after ischemic stroke. Methods: Five hundred and three acute ischemic stroke patients with normal left ventricular ejection fraction (≥50%) were retrospectively included. Echocardiography and tissue Doppler imaging were used to evaluate and grade diastolic function. Ordinal logistic and Cox regression analyses were used to examine relations between DD and modified Rankin Scale (mRS) score at 3 months and mortality after stroke, respectively. Results: Mean age was 67.2 ± 11.8 years and 63% were men. Among parameters of diastolic function, early mitral inflow velocity/early diastolic mitral annulus velocity (E/e') was independently related with higher mRS score at 3 months and mortality after ischemic stroke. The highest quartile of E/e' (>14) was independently associated with higher mRS score (adjusted OR 3.86, 95% CI 2.27-6.54) as well as with mortality (hazards ratio [HR] 2.87, 95% CI 1.17-7.04) as compared to the lowest quartile of E/e' (<8.8). In addition, moderate-to-severe DD grade was related to higher mRS score (adjusted OR 2.41, 95% CI 1.15-5.06) and mortality (HR 6.63, 95% CI 1.80-24.43) compared to the normal diastolic function. Conclusion: In patients with ischemic stroke, DD is associated with functional outcome at 3 months and mortality. Our data suggest that more attention should be given to DD in patients with ischemic stroke.

Retinal Artery Occlusion and the Risk of Stroke Development: Twelve-Year Nationwide Cohort Study

BACKGROUND AND PURPOSE

Our aim was to evaluate the risk of subsequent stroke development after retinal artery occlusion (RAO).

METHODS

National registry data were collected from the Korean National Health Insurance Service, comprised 1 025 340 random subjects. Patients diagnosed with RAO in 2002 and 2003 were excluded. The RAO group was composed of patients with an initial diagnosis of either central or other RAO between January 2004 and December 2013 (n=401). The comparison group was composed of randomly selected patients (5 per RAO patient; n=2003) who were matched to the RAO group according to sociodemographic factors and year of RAO diagnosis. Each sampled patient was tracked until 2013. Cox proportional hazard regression was used.

RESULTS

Stroke occurred in 15.0% of the RAO group and in 8.0% of the comparison group (P < 0.001). RAO was associated with an increased risk of stroke occurrence (hazard ratio, 1.78; 95% confidence interval, 1.32-2.41). The magnitude of the RAO effect for stroke was larger among younger adults aged <65 years (hazard ratio, 3.11) than older adults aged ≥65 years (hazard ratio, 1.26). However, the risk of subsequent stroke was significantly increased in older adults aged ≥65 years at the 4-year follow-up (hazard ratio, 1.58; 95% confidence interval, 1.01-2.48).

CONCLUSIONS

RAO was significantly associated with subsequent stroke after adjusting for comorbidities and sociodemographic factors. These findings are limited by uncontrolled confounding factors and need to be replicated by other observational studies.

Implementation of safe sleep practices in the neonatal intensive care unit

OBJECTIVE

To increase the percentage of eligible infants engaging in safe sleep practices (SSP) in two level III neonatal intensive care units (NICUs) in the Boston, Massachusetts area.

STUDY DESIGN

On the basis of eligibility criteria (⩾34 weeks or ⩾1800 g without acute medical conditions), all infants were eligible for two sleep practices: SSP or NICU therapeutic positioning (NTP) depending on their gestational age, weight, clinical illness and need for therapeutic interventions. Compliance with SSP was defined as: (1) supine positioning, (2) in a flat crib with no incline, (3) without positioning devices and (4) without toys, comforters or fluffy blankets. NTP comprised usual NICU care. Nursing education was comprised of a web-based learning module and in-person teaching sessions with a study team member. Double-sided crib cards (SSP one side and NTP on the other) were attached to the bedside of every infant. Pre- and postintervention audits of all infants were carried out at both study sites. We compared compliance across all time points using generalized estimating equations to account for correlated data (SAS v9.3, Cary, NC, USA).

RESULT

Of 755 cases, 395 (52.3%) were assessed to be eligible for SSP. From the pre- to post-intervention period, there was a significant improvement in overall compliance with SSP (25.9 to 79.7%; P-value<0.001). Adherence to each component of SSP also improved significantly following the intervention.

CONCLUSION

Safe infant sleep practices can be integrated into the routine care of preterm infants in the NICU. Modeling SSP to families far in advance of hospital discharge may improve adherence to SSP at home and reduce the risk of sleep-related morbidity and mortality in this vulnerable population of infants.

Presumed Regional Incidence Rate of Out-of-Hospital Cardiac Arrest in Korea

The regional incidence rates of out-of-hospital cardiac arrest (OHCA) were traditionally calculated with the residential population as the denominator. The aim of this study was to estimate the true incidence rate of OHCA and to investigate characteristics of regions with overestimated and underestimated OHCA incidence rates. We used the national OHCA database from 2006 to 2010. The nighttime residential and daytime transient populations were investigated from the 2010 Census. The daytime population was calculated by adding the daytime influx of population to, and subtracting the daytime outflow from, the nighttime residential population. Conventional age-standardized incidence rates (CASRs) and daytime corrected age-standardized incidence rates (DASRs) for OHCA per 100,000 person-years were calculated in each county. A total of 97,291 OHCAs were eligible. The age-standardized incidence rates of OHCAs per 100,000 person-years were 34.6 (95% CI: 34.3-35.0) in the daytime and 24.8 (95% CI: 24.5-25.1) in the nighttime among males, and 14.9 (95% CI: 14.7-15.1) in the daytime, and 10.4 (95% CI: 10.2-10.6) in the nighttime among females. The difference between the CASR and DASR ranged from 35.4 to -11.6 in males and from 6.1 to -1.0 in females. Through the Bland-Altman plot analysis, we found the difference between the CASR and DASR increased as the average CASR and DASR increased as well as with the larger daytime transient population. The conventional incidence rate was overestimated in counties with many OHCA cases and in metropolitan cities with large daytime population influx and nighttime outflow, while it was underestimated in residential counties around metropolitan cities.

The Effect of Asthma Clinical Guideline for Adults on Inhaled Corticosteroids PrescriptionTrend: A Quasi-Experimental Study

In order to increase inhaled corticosteroid (ICS) use and to reduce hospitalization, emergency department visits and ultimately the economic burden of asthma, "Korean Asthma Management Guideline for Adults 2007" was developed. To assess the guideline effects on physician's ICS prescription for asthma, we conducted segmented regression and multilevel logistic regression using National Health Insurance claims database of outpatient visits from 2003 to 2010. We set each quarter of a year as a time unit and compared ICS prescription between before and after guideline dissemination. A total of 624,309 quarterly visits for asthma was observed. The ICS prescription rate before and after guideline dissemination was 13.3% and 16.4% respectively (P < 0.001). In the segmented regression, there was no significant guideline effect on overall ICS prescription rate. In multilevel logistic regression analyses, the effect of guideline on overall ICS prescription was not significant (odds ratio, 1.03; 95% CI, 1.00-1.06). In subgroup analysis, ICS prescription increased in secondary care hospitals (odds ratio, 1.15; 95% CI, 1.02-1.30) and in general hospitals (odds ratio, 1.10; 95% CI, 1.04-1.16). However, in primary clinics, which covered 81.7% of asthma cases, there was no significant change (odds ratio, 0.98; 95% CI, 0.94-1.02). From the in-depth interview, we could identify that the reimbursement criteria of the Health Insurance Review and Assessment Service and patient's preference for oral drug were barriers for the ICS prescription. The domestic asthma clinical guideline have no significant effect on ICS prescription, especially in primary clinics.