Suicide risk of chronic diseases and comorbidities: A Korean case-control study.

OBJECTIVES: Chronic diseases including mental disorders have been associated with suicide. This study broadens the approach by incorporating a comprehensive list of chronic diseases and a context of comorbidities and explored their associations with suicide. METHODS: Data-linkage between death registry and Korean National Health Insurance data was conducted. Suicide cases (n = 64,099) between 2009 and 2013 were 1:4 matched for gender and age to an alive control (n = 256,396). A total of 92 individual diseases of 9 broad categories were identified from insurance claims data. Conditional logistic regression was applied to assess the associations, adjusting for mental and behavioral disorders and socioeconomic status. RESULTS: Suicide cases frequently experienced chronic diseases (90.0 %) and comorbidities (74.6 %). Chronic diseases greatly increased suicide risk and, among these, mental and behavioral disorders showed the highest suicide risk (OR = 7.53, 95 % CI = 7.32-7.74) followed by cardiovascular (OR = 3.36, 95 % CI = 3.26-3.47). For individual diseases, gastritis and duodenitis were most prevalent (68.1 %) among suicide cases but depressive disorder showed the highest risk (OR = 4.95, 95 % CI = 4.79-5.12). Suicide risk was strong in comorbid status sometimes comparable to odds for mental and behavioral disorder alone (e.g., OR for cardiovascular and eye vision-related diseases = 4.01, 95 % CI = 3.86-4.17). LIMITATIONS: Differentiation of comorbidity was limited to pairs between major disease categories, neglecting the heterogeneity within categories. CONCLUSION: Chronic diseases, in particular comorbidity, showed strong associations with suicide. This suggests that those with comorbidities feel that they are pushed to the extreme line, supporting comprehensive interventions for them to address wider reasons including psychological and social problems, besides medical problems.

Comparison of mortality and short-term outcomes between classic, intubation-surfactant-extubation, and less invasive surfactant administration methods of surfactant replacement therapy.

Background: Intubation-Surfactant-Extubation (InSurE) and less invasive surfactant administration (LISA) are alternative surfactant replacement therapy methods for reducing the complications associated with invasive mechanical ventilation. This study aimed to compare the Classic, InSurE, and LISA methods in Very-Low-Birth-Weight infants (VLBWIs) in South Korea. Methods: The Korean Neonatal Network (KNN) enrolled VLBWIs born between January 1, 2019 and December 31, 2020. They were analyzed retrospectively to compare the duration of respiratory support, length of hospitalization, mortality, and short-term outcomes of the three groups. Results: The duration of invasive ventilator support was shorter in the following order: InSurE (3.99 ± 11.93 days), LISA (8.78 ± 29.32 days), and the Classic group (22.36 ± 29.94 days) (p = 0.014, p < 0.01) and InSurE had the shortest hospitalization (64.91 ± 24.07 days, p < 0.05) although the results couldn't adjust for confounding factor because of irregular distribution. InSurE had the lower risk of intraventricular hemorrhage (IVH) grade II-IV [odds ratio (OR) 0.524 [95% confidence interval (CI): 0.287-0.956], p = 0.035] than in the Classic group. Mortality was lower in the InSurE [OR 0.377 (95% CI: 0.146-0.978), p = 0.045] and LISA [OR 0.296 (95% CI: 0.102-0.862), p = 0.026] groups than in the Classic group. There was a reduced risk of moderate to severe bronchopulmonary dysplasia (BPD) [OR 0.691 (95% CI: 0.479-0.998, p = 0.049), OR 0.544 (95% CI: 0.355-0.831, p = 0.005), respectively], pulmonary hypertension [OR 0.350 (95% CI: 0.150-0.817, p = 0.015), OR 0.276 (95% CI: 0.107-0.713, p = 0.008), respectively], periventricular leukomalacia (PVL) [OR 0.382 (95% CI: 0.187-0.780, p = 0.008), OR 0.246 (95% CI: 0.096-0.627, p = 0.003), respectively], and patent ductus arteriosus (PDA) with treatment [OR 0.628 (95% CI: 0.454-0.868, p = 0.005), OR 0.467 (95% CI: 0.313-0.696, p < 0.001) respectively] in the InSurE and LISA groups compared to the Classic group. Conclusion: InSurE showed the lowest duration of invasive ventilator support, length of hospitalization. InSurE and LISA exhibited reduced mortality and decreased risks of moderate to severe BPD, pulmonary hypertension, PVL, and PDA with treatment compared to the Classic group.

Increased suicide risk of psychiatric patients following the recent utilization of health care services: results from a nationwide cohort study in South Korea.

Purpose: This study aimed to examine whether and to what degree the suicide risk of psychiatric patients is associated with psychiatric and non-psychiatric health service utilization. Methods: We selected incident psychiatric patients, including schizophrenia, bipolar disorders, borderline personality disorder, depressive disorders, other affective disorders, and post-traumatic stress disorder patients, in 2007-2010 and followed them up until 2017 based on the data linkage between the Korean National Health Insurance and National Death Registry. We analyzed the time-dependent association between suicide and four types of health service (psychiatric vs. non-psychiatric and outpatient vs. inpatient) utilization using a time-dependent Cox regression. Results: The suicide risk of psychiatric patients was significantly increased with recent psychiatric and non-psychiatric admission and psychiatric outpatient visits. The adjusted suicide hazard ratios for recent outpatient visits were similar to or even higher than those for recent psychiatric admission. The adjusted suicide hazard ratios of schizophrenia patients for psychiatric admission, psychiatric outpatient visits, and non-psychiatric admission within the recent 6 months were 2.34 (95% confidence interval [CI]: 2.12-2.58, p < 0.001), 2.96 (95% CI: 2.65-3.30, p < 0.001), and 1.55 (95% CI: 1.39-1.74, p < 0.001), respectively. Suicide risk was not associated with recent non-psychiatric outpatient visits in patients, except for the depressive disorders group showing a negative association. Conclusion: Our results highlight the priority of suicide prevention for psychiatric patients in the clinical setting. Additionally, our results warrant the precaution against increased suicide risk of psychiatric patients after psychiatric and non-psychiatric discharge.

Characterization of Rotavirus Infection in Hospitalized Children under 5 with Acute Gastroenteritis 5 Years after Introducing the Rotavirus Vaccines in South Korea.

We herein characterized rotavirus infection in hospitalized children under 5 years of age with gastroenteritis after introducing rotavirus vaccines in South Korea from 20 February 2012, to 31 March 2013. Enzyme-linked fluorescent immunoassay was performed to detect rotavirus antigens. G and P genotyping was performed using nested multiplex PCR. For the failed PCR samples, sequencing was conducted. We performed a test-negative case-control study to estimate vaccine effectiveness. Vaccine effectiveness was measured using a multivariate logistic regression model. Rotavirus was detected in 16 (13.2%) of the 121 patients, with a seasonal peak in April 2012. The dominant genotypes detected were G3P[8] (33.3%) and G4P[6] (26.7%), and vaccine effectiveness against rotavirus hospitalization was 84.9% [95% CI: 23.2−97.0] in the complete vaccinated group. A higher prevalence of rotavirus infection was observed among children with siblings than those without siblings (p < 0.001). Also, the presence of siblings was significantly associated with a history of nonvaccination (p < 0.001). In conclusion, the prevalence of rotavirus followed a decreasing trend, and there was no evidence of emergences of nonvaccine-type strains. Vaccine effectiveness against rotavirus hospitalization was 84.9%. Although children with siblings were more susceptible to rotavirus infection, they were less likely to receive vaccination against rotavirus.

Preventive health behaviors among people with suicide ideation using nationwide cross-sectional data in South Korea.

This study aimed to investigate the association between suicide ideation and health-related behaviors and preventive health service use behaviors. We used data from the 2017 Korea National Health and Nutrition Examination Survey (KNHANES), a nationally representative survey. The final sample included 4486 participants aged 40 years or older. Preventive health behaviors were assessed for smoking, high-risk drinking, physical activities, regular meal intake, influenza vaccination, general health examination, and cancer screening. Logistic regression was used to examine the association between suicide ideation and preventive health behaviors with a series of adjustments for covariates. In general, suicide ideation was associated with unfavorable outcomes of preventive health behaviors, except for flu vaccination. For example, the adjusted prevalence of suicide ideation and non-suicide ideation groups were 54.3% vs. 43.7% for flu vaccination, 23.1% vs. 41.6% for physical activity, and 24.8% vs. 18.6% for high-risk alcohol drinking. After adjustment for covariates, the associations of suicide ideation with behaviors remained significant for physical activity (OR 0.52, 95% CI 0.34-0.81) and high-risk alcohol drinking (OR 2.22, 95% CI 1.34-3.69). Suicide ideation leads to the disruption of self-management of health behaviours, especially for physical activity and high-risk alcohol drinking, independently of depressive feelings.

Incidence, Clinical Characteristics, and Genotype Distribution of Rotavirus in a Neonatal Intensive Care Unit 5 Years After Introducing Rotavirus Vaccine.

BACKGROUND: Rotavirus (RV) is a common cause of viral gastroenteritis in children worldwide. We aimed to investigate the incidence, symptoms, and genotype of RV infection in a neonatal intensive care unit (NICU) in South Korea 5 years after the introduction of RV vaccination to evaluate its effect on newborn infants. METHODS: A total of 431 fecal specimens were collected from patients admitted to NICU between April 20, 2012 and September 10, 2013. Enzyme-linked immunoassays were used to detect RV antigen. Nested multiplex polymerase chain reaction was used for genotyping. RESULTS: The overall incidence of RV infection was 43.9% and was significantly higher in preterm infants, infants born in the study hospital, low birth weight infants, and cesarean births (P < 0.05). Symptoms of diarrhea, poor feeding, abdominal distension, and apnea were significantly higher in infants with RV infection than those without infection. RV infection gradually increased depending on infant care at home, postpartum clinic, or hospital (26.0, 45.1, and 60.2%, respectively; P = 0.000). The dominant RV genotype in the NICU was G4P[6] at 95.4%. CONCLUSION: Current RV vaccines did not affect the incidence of RV infection in newborn and preterm infants in the NICU. Most RV-positive patients in the NICU had symptoms, and the incidence of RV infection was relatively higher in hospitals and postpartum clinics with group life than home. The dominant RV genotype was G4P[6] across study groups.

Financial hardship and suicide ideation: Age and gender difference in a Korean panel study.

BACKGROUNDS: Socioeconomic factors influence suicide risk but a systematic understanding of the role of financial hardship is unclear. We examined whether financial hardship had cumulative or contemporaneous impacts on suicide ideation and any gender and age differences in a large Korean sample. METHODS: Data of 67,728 observations from 14,321 individuals were extracted from seven waves of Korean Welfare Panel Study. The association of financial hardship at baseline and its change over two years with suicide ideation was investigated using generalized estimation equation to account for repeated measurements within an individual, adjusting for other socioeconomic factors. RESULTS: Financial hardship was associated with suicide ideation but the magnitude of association varied across age and gender groups. Specifically, the impact of financial hardship was persistent over two years presenting a cumulative effect among men aged 50-64 years and ≥65 years; e.g., adjusted OR (adjusted odds ratio) = 3.87, 95 % CI = 2.71-5.54 for emergent hardship group vs adjusted OR = 4.22, 95 %CI = 3.00-5.93 for persistent group in those aged ≥65 years. Financial hardship increased the risk of suicide ideation incrementally with age, although the pattern was less clear among women. LIMITATIONS: Financial hardship was identified as having changing nature, though it was assumed to occur over two years. CONCLUSION: In general, financial hardship plays a role in amplifying suicide ideation in a contemporaneous way but also in a cumulative way, predominantly among late-middle-aged and elderly men. Monitoring and intervention for financial hardship would be a promising strategy for suicide prevention.

Small but protective social capital against suicide ideation in poor communities: A community-based cross-sectional study.

Coupled with the lowest level of social connectedness, South Korea has the highest suicide rate among the Organization for Economic Co-operation and Development countries. A possible link between community and suicide is social capital imprinted in social connectedness. This study explores whether social capital is protective against suicide ideation in relation to the poverty level of communities, and whether the associations are specific to certain elements of social capital.A total of 908 participants were included to assess cross-sectional association of social capital at individual level with suicide ideation by comparing between poor (government-leased apartments) and non-poor communities (nongovernment-leased apartments). Logistic regression analyses were performed to examine various social capital dimensions in relation to suicide ideation.Suicide ideation was far higher among those living in the poor communities (poor communities 12%; non poor communities 6.3%) and the level of social capital was lower in the poor communities. Nevertheless, the protective effect of social capital, in particular, the cognitive dimension against suicide ideation was demonstrated only in the poor communities (eg, odds ratio = 0.27, 95% confidence interval: 0.12-0.58 for trust in the poor communities). Low income was significantly associated with suicide ideation only in the poor communities, but depression and resilience were associated with suicide ideation both in the poor and non-poor communities.To increase the reliability of the results, established measures based on relevant literature were utilized, but measures on bridging social capital and social network might have relatively low reliability.As to protection against suicide ideation, the extent of reliance on social capital was higher in poor communities than in non-poor communities, in particular, the cognitive dimension was likely to activate in this regard.

Emphysema is associated with the aggressiveness of COPD-related adenocarcinomas.

OBJECTIVES: To compare the differences in radiologic and pathologic features of surgically resected chronic obstructive pulmonary disease (COPD)-related adenocarcinomas according to the presence of emphysema. METHODS: A total of 216 smokers with surgically resected lung adenocarcinoma were included in this retrospective study, and 102 patients were diagnosed with COPD. We classified COPD patients as emphysematous or non-emphysematous group based on the emphysema severity on computed tomography (CT) and evaluated the differences in the CT and pathologic features between the two groups. The relationship between emphysema and disease-free survival was assessed using a Kaplan-Meier curve. RESULTS: Lung adenocarcinomas in emphysema group presented a more aggressive pathologic grade and higher prevalence of solid lesions (vs subsolid lesions) on CT than those in non-emphysematous group (P = 0.006 and <0.001, respectively). After adjustment for age, sex, smoking pack-years and tumor size, emphysema group had a greater risk for higher histologic grade and higher prevalence of solid lesions than non-emphysema group (odds ratio, 3.445; 95% confidence interval, 1.124-10.564; P = 0.030, odds ratio, 6.192; 95% confidence interval, 1.804-21.254; P = 0.004, respectively). Kaplan-Meier survival curves showed that patients with emphysema had significantly impaired disease-free survival compared with those without emphysema (median disease-free survival = 37.0 vs 57.5 months, P = 0.038). CONCLUSION: Adenocarcinomas in emphysema-present COPD had more aggressive features of pathology and CT findings, and worse disease-free survival than those without emphysema. These findings might provide an insight into the different pathobiology and prognostic implications of lung adenocarcinomas according to the presence of emphysema in patients with COPD.

An Assessment of Magnitudes and Patterns of Socioeconomic Inequalities across Various Health Problems: A Large National Cross-Sectional Survey in Korea.

Magnitudes of health inequalities present consequences of socioeconomic impact on each health problem. To provide knowledge on the size of health problems in terms of socioeconomic burden, we examined the magnitudes and patterns of health inequalities across 12 health problems. A total of 17,292 participants older than 30 years were drawn from the Korea National Health and Nutrition Examination Survey (KNHANES, 2010⁻2012). The age-adjusted prevalence ratios were compared across socioeconomic positions (SEPs) based on income, education, and occupation. The magnitudes of socioeconomic inequalities varied across 12 health problems and, in general, the patterns of socioeconomic inequalities were similar among groups of health problems (i.e., non-communicable diseases (NCDs), mental health, and subjective health states). Significant health inequalities across NCDs, such as diabetes, hypertension, ischemic heart disease, and arthritis, were observed mainly in women. Socioeconomic inequalities in mental health problems, such as depression, suicidal ideation, and suicide attempts, were profound for both genders and across SEP measures. Significant socioeconomic inequalities were also observed for subjective health. No or weak associations were observed for injury and HBV infection. The patterns of socioeconomic inequalities were similar among groups of health problems. Mental illnesses appeared to require prioritization of socioeconomic approaches for improvement in terms of absolute prevalence and relative socioeconomic distribution.

Changing patterns of adult asthma incidence: results from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database in Korea.

This study was conducted to assess the changes in the annual incidence of adult asthma in Korea where the prevalence of asthma had increased steadily in recent decades. A population-based cohort study was conducted using the National Health Insurance Service-National Sample Cohort (NHIS-NSC), which consisted of 746,816 adults aged >20 years between 2004 and 2012. Asthma was defined by two or more physician claims on the basis of a primary diagnostic code for asthma and administration of asthma medications within 1 year. The incidence rates and annual percent change were calculated, and the influence of age and sex on the incidence rates was studied. The annual asthma incidence increased from 3.63 in 2004 to 6.07 per 1,000 person-years in 2008. Since 2008, the asthma incidence did not change significantly. The asthma incidence was higher in women than in men throughout the study periods (p < 0.001) and higher in older than younger age groups (p < 0.001). The asthma incidence did not change in all ages since 2008, except for the 20 s who showed a steady increase. The incidence of asthma in adults reached plateau in Korea, which is consistent with the results from studies in other countries.

The Epidemiological Influence of Climatic Factors on Shigellosis Incidence Rates in Korea.

Research has shown the effects of climatic factors on shigellosis; however, no previous study has evaluated climatic effects in regions with a winter seasonality of shigellosis incidence. We examined the effects of temperature and precipitation on shigellosis incidence in Korea from 2002⁻2010. The incidence of shigellosis was calculated based on data from the Korean Center for Disease Control and Prevention (KCDC, Cheongju, Korea), and a generalized additive model (GAM) was used to analyze the associations between the incidence and climatic factors. The annual incidence rate of shigellosis was 7.9 cases/million persons from 2002⁻2010. During 2007⁻2010, high incidence rates and winter seasonality were observed among those aged ≥65 years, but not among lower age groups. Based on the GAM model, the incidence of shigellosis is expected to increase by 13.6% and 2.9% with a temperature increase of 1 °C and a lag of two weeks and with a mean precipitation increase of 1 mm and a lag of five weeks after adjustment for seasonality, respectively. This study suggests that the incidence of shigellosis will increase with global climate change despite the winter seasonality of shigellosis in Korea. Public health action is needed to prevent the increase of shigellosis incidence associated with climate variations.

Age, Period, and Cohort Effects on Suicide Mortality in South Korea, 1992⁻2015.

Although the effects of age, period, and cohort (APC) on suicide are important, previous work in this area may have been invalid because of an identification problem. We analyzed these effects under three different scenarios to identify vulnerable groups and thus overcame the identification problem. We extracted the annual numbers of suicides from the National Death Register of Korea (1992⁻2015) and estimated the APC effects. The annual average suicide rates in 1992⁻2015 were 31.5 and 14.7 per 100,000 males and females, respectively. The APC effects on suicide were similar in both sexes. The age effect was clearly higher in older subjects, in contrast to the minimal changes apparent during earlier adulthood. The birth cohort effect showed an inverted U shape; a higher cohort effect was evident in females born in the early 1980s when period drift was larger than 3.7%/year. Period effect increased sharply during the early 1990s and 2000s. We found that elderly and young females may be at a particularly high risk of suicide in Korea.

Risk factors for feelings of sadness and suicide attempts among cancer survivors in South Korea: findings from nationwide cross-sectional study (KNHANES IV-VI).

INTRODUCTION: As the number of cancer survivors is rapidly increasing with the increased incidence of the disease and improved survival of patients, the prevalence of, and risk factors for, mental health problems and suicidality among cancer survivors should be examined. METHODS AND ANALYSIS: Using data obtained from the Korean National Health and Nutrition Examination Survey (2007-2013), we examined 1285 and 33 772 participants who had been and never been diagnosed with cancer, respectively. We investigated the risks of feelings of sadness and suicide attempts among cancer survivors and general population and examined differences in the risks of cancer survivors among subgroups according to cancer-related characteristics. RESULTS: The median age of survivors at the time of the survey and at diagnosis was 63 and 54 years, respectively. After adjusting for sex, level of education, household income, occupation, marital status, cancer type, current status of treatment, age at diagnosis and years since diagnosis, the risk of suicide attempts was significantly higher in participants diagnosed with cancer before 45 years of age compared with those diagnosed at 45-64 years (adjusted OR=3.81, 95% CI 1.07 to 13.60, P=0.039), and the higher risk of suicide attempts with borderline significance was found in those for whom more than 10 years had passed since diagnosis compared with those for whom the diagnosis was made only 2-10 years ago (adjusted OR=3.38, 95% CI 0.98 to 11.70, P=0.055). However, feelings of sadness were not significantly associated with any cancer-related characteristic. CONCLUSION: Our results reveal an increased risk of suicide attempts among cancer survivors diagnosed early in life and in those for whom more than 10 years has passed since the diagnosis, suggesting the need for intensive monitoring and support for mental health problems and suicidal risks in this population.

Socioeconomic inequalities in health in the context of multimorbidity: A Korean panel study.

Socioeconomic inequalities in health are commonly known to decrease at late age. Yet, it remains unclear whether socioeconomic inequalities in health at late age appear in relation to multimorbidity, particularly in Korea where social support remains unsatisfactory for older people. Using three waves of Korea Health Panel, data of 19,942 observations with repeated measure were constructed to ensure a temporal sequence between three socioeconomic measures (i.e., poverty, employment status, and education) and multimorbidity with a t to t+1 year transition. A multilevel multinomial model was applied to quantify the socioeconomic impact across different age, diseases and disease groups, both separately and in combination. There were associations between socioeconomic position (SEP) and multimorbidity, and increasing trends of socioeconomic inequalities not only with greater number of morbidity but also with age. The latter result was only observed with employment status through mid-to-early old age; i.e., between the 40s (odds ratio (OR) = 2.45, 95% confidence interval (CI):1.08-5.57) and 70s (OR = 3.48, 95%CI: 1.24-9.74). The patterns of socioeconomic inequalities in multimorbidity varied for particular pairs of diseases and were stronger in the disease pairs co-occurring with mental and cardiovascular diseases but weaker in the disease pairs co-occurring with cancer. Accumulation of adversity tended to intensify with increase in number of diseases and older age, though this finding was not consistently supported. The labour market should be encouraged to actively participate in actions to promote healthy aging needs to be complemented by the provision of more generous and universal income support to the elderly in Korea.

Differentiation of direct and indirect socioeconomic effects on suicide attempts in South Korea.

Despite the wide recognition of the inverse association between socioeconomic position (SEP) and suicidal behaviors, its underlying process and potential mediators are little known. This study investigated the pathway from SEP to suicide attempts with attention to potential mediators.From the Korean Health and Nutrition Examination Survey 2007-2013, which is a nationwide cross-sectional survey of the health and nutritional status, a total of 34,565 participants (≥30 years) were included in the analysis. To unfold the pathways linking SEP to suicide attempts, the direct and indirect effects of 3 SEP measures (educational attainment, household income, and occupational group) and 3 mediators (physical illness, mental health problems, and problematic drinking) were differentiated using structured equation model (SEM).Most of direct and indirect effects of educational attainment, household income, and occupational group on suicide attempts were significant; Nonemployment status had the largest total (ß = 0.291, P < .01) and direct effects (ß = 0.212, P < .01), while educational attainment had the largest indirect effect (ß = -0.124, P < .01). Educational attainment was mainly mediated by physical illness and problem drinking, whereas household income and occupational group were mainly mediated by anxious or depressed mood and problem drinking. Physical illness played a major role in explaining suicide attempts, compared to mental health problem and problem drinking.Overall, experience of socioeconomic disadvantage increased suicide attempts independently of mental and physical problems. An extension of suicide prevention program is required for comprehensively targeting people with general problems such as physical illness and low SEP, complemented to narrowly targeting high risk group with, such as mental health problem.

Seropositivity among Korean Young Adults Approximately 2 Years after a Single-Dose Vaccination against Hepatitis A Virus.

We previously observed 80.7% seropositivity and a significant interaction between gender and hepatitis A virus (HAV) vaccine type (Havrix vs. Epaxal) on the seropositivity approximately 11 months after single-dose HAV vaccinations in Korean young adults. Our objective was to evaluate seropositivity approximately 2 years after a single-dose HAV vaccination and the influence of demographic characteristics on seropositivity, including the interaction between gender and vaccine type. Seronegative medical school students were randomly vaccinated with Havrix or Epaxal. Based on a total serum anti-HAV antibody titer cutoff of 20 IU/mL, 338 participants (76.0%) of the 445 vaccinees were seropositive 20-25 months after a single-dose HAV vaccination. The seropositive rates were similar after vaccination with Havrix (77.0%) and Epaxal (74.9%). Univariate analysis indicated that female (p = 0.052) and less obese (p < 0.001) participants had a higher seropositive rate, whereas other characteristics such as age, alcohol use, smoking history, vaccine type, and follow-up duration were not associated with seropositivity. Multivariate analysis indicated that women (p = 0.026) and participants with moderate alcohol use (p < 0.001) showed significantly higher seropositive rates than men and participants with no or low alcohol use, respectively. The seropositive rates after vaccination with Havrix and Epaxal were 70.9% and 67.5% in men and 87.7% and 91.3% in women, respectively (p for interaction = 0.304). Compared with the seropositive rate approximately 11 months after vaccination, the seropositive rate decreased substantially only in men in the Havrix group (11.0% points), and consequently, the interaction between gender and vaccine type disappeared while seropositivity remained high (87.7% and 91.3% in Havrix and Epaxal groups, respectively) among women approximately 2 years after vaccination. Further studies are needed to assess whether the seropositive rate would be maintained in all groups more than 2 years after a single-dose HAV vaccination.

Relationship Between Emphysema Severity and the Location of Lung Cancer in Patients With Chronic Obstructive Lung Disease.

OBJECTIVE: New phenotypes of chronic obstructive pulmonary disease (COPD) based on emphysema severity have been recognized recently. The purpose of this study was to determine the relationship between emphysema severity (phenotype) and lung cancer location in patients with COPD. MATERIALS AND METHODS: Four hundred patients with 405 primary lung cancers confirmed pathologically between January 2010 and March 2014 were included in the study. Of these, 193 patients received a diagnosis of COPD according to the Global Initiative for Chronic Obstructive Lung Disease guidelines. We scored emphysema severity (0-4) on thin-section CT and assigned the anatomic tumor location of lung cancer as peripheral or central. RESULTS: Patients with COPD had a higher proportion of centrally located lung cancer compared with those without COPD (36.4% vs 17.4%; p < 0.001). In patients with COPD, lower emphysema grades (odds ratio [OR], 0.69; 95% CI, 0.51-0.93; p = 0.016) and reduced ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) (OR, 0.94; 95% CI, 0.89-0.99; p = 0.024) were associated with central location. After adjusting for age, smoking, and spirometry results, the proportion of central location was approximately four times higher in patients with lower emphysema grades (0-2, < 25%) than in those with severe grades (grade 4, > 51%). CONCLUSION: Lower emphysema grades and reduced FEV1/FVC seemed to be independent predictors of central location of lung cancer in COPD. Therefore, in patients with COPD with lower grade emphysema and airway-predominant disease, additional screening tools may have to be considered for central lung cancer detection along with thin-section CT.

The immunogenicity of a single dose of hepatitis A virus vaccines (Havrix® and Epaxal®) in Korean young adults.

PURPOSE: Assessing the immunogenicity of a single dose of hepatitis A virus (HAV) vaccines is important because some people receive only a single dose. However, previous studies have shown variable results and have not examined the effects of demographic characteristics other than gender. This study was performed to examine the immunogenicity of a single dose of HAV vaccine according to the vaccine type and demographic characteristics in young adults. MATERIALS AND METHODS: Seronegative medical school students were randomly allocated to receive either Havrix or Epaxal. RESULTS: After approximately 11 months, the seroconversion rate in 451 participants was 80.7%. In men, the Havrix group showed a significantly higher seroconversion rate (81.9%) than the Epaxal group (69.2%), whereas both vaccine groups showed similarly high immunogenicity in women (Havrix: 90.1%, Epaxal: 92.9%; P for interaction=0.062). According to the results of a multivariate analysis, Epaxal showed significantly lower immunogenicity than Havrix only in men. Age, obesity, drinking, smoking, and follow-up time did not significantly affect seroconversion in either gender. CONCLUSION: The seroconversion rate of single-dose HAV vaccines was low in men, particularly in those who received Epaxal. Our results suggest that gender effects should be considered when comparing the immunogenicity of different HAV vaccines.