Fracture Risk Among Stroke Survivors According to Poststroke Disability Status and Stroke Type.

BACKGROUND: Stroke survivors face physical and cognitive challenges, leading to an increased dependency and a higher fall risk. We aimed to investigate the impact of poststroke disability and stroke type on fracture risk at various sites compared with matched controls. METHODS: This retrospective cohort study used data from the Korean National Health Insurance System database (2010-2018), including patients with stroke and 1:1 matched controls. Stroke survivors were grouped based on the presence and severity of their poststroke disability and stroke type. The primary outcome was a newly diagnosed fracture, analyzed by Cox proportional hazard regression analyses adjusting for potential confounders. RESULTS: Among 223 358 stroke survivors (mean age, 64.8±10.9 years; 61.2% men), 16 344 fractures occurred during a mean follow-up of 3.7±2.5 years. In matched controls (n=322 161; mean age, 65.4±11.2 years; 61.3% men), 20 398 fractures were identified. Stroke survivors had increased overall fracture risk compared with matched controls (adjusted hazard ratio [aHR], 1.40 [95% CI, 1.37-1.43]). Specifically, hip fracture risk was even greater in stroke survivors (incidence rate per 1000 person-years, 4.7 [95% CI, 4.5-4.8]; aHR, 2.42 [95% CI, 2.30-2.55]) than controls (incidence rate, 2.2 [95% CI, 2.1-2.3]). The risk of vertebral fractures (aHR, 1.29 [95% CI, 1.25-1.34]) and other fractures (aHR, 1.19 [95% CI, 1.15-1.23]) was also higher than that of the control group. Hip fracture risk was the highest among stroke survivors with severe poststroke disability (aHR, 4.82 [95% CI, 4.28-5.42]), although vertebral or other fracture risk was the highest among those with mild poststroke disability. No significant difference in fracture risk was found between hemorrhagic and ischemic stroke survivors when stratified by disability status. CONCLUSIONS: Our findings showed increased subsequent fracture risk among stroke survivors, particularly those with poststroke disability and for hip fracture. Bone health assessment and treatment should be emphasized as an essential part of stroke management.

Association between dental diseases and oral hygiene care and the risk of vertebral fracture: a nationwide cohort study.

Periodontal disease and increased missing teeth were associated with incident vertebral fractures. In contrast, professional dental cleaning and frequent tooth brushing, was associated with a lower risk of vertebral fracture. Better oral hygiene care attenuated the risk associated with dental diseases. PURPOSE: To investigate the association between oral health and the risk of vertebral fractures. METHODS: We included 2,532,253 individuals aged ≥40 years who underwent the Korean National Health Insurance Service health examinations in 2008 and followed up until December 31, 2017. We performed multivariable Cox proportional hazard regression analyses to evaluate the association between dental diseases and oral hygiene care and the risk of vertebral fractures. RESULTS: Over the 9.3-year median follow-up, 1.46% (n = 36,857) experienced vertebral fractures. Individuals with dental diseases had a higher risk of vertebral fracture than those without (hazard ratio [HR] 1.04, 95% confidence interval [CI]: 1.02-1.07 for periodontal diseases; 1.02, 1.00-1.05 for dental caries; 1.12, 1.05-1.20 for ≥15 missing teeth). Good oral hygiene care was associated with a lower vertebral fracture risk (HR 0.89, 95% CI: 0.86-0.91 for ≥1 time/year [vs. <1 time/year] of professional dental cleaning; 0.90, 0.87-0.93 for ≥2 times/day [vs. 0-1 time/day] of toothbrushing). The combined dental diseases was significantly associated with an increased vertebral fracture risk, whereas combined oral hygiene care was associated with further risk reduction. Better oral hygiene care reduced vertebral fracture risk associated with dental diseases (all P <0.001). CONCLUSION: Periodontal disease, dental caries, and an increased number of missing teeth were independently associated with higher risks for vertebral fractures. Conversely, improved oral hygiene care, such as personal dental cleaning and frequent tooth brushing, may modify vertebral fracture risks associated with dental disease.

Tuberculosis and the Risk of Ischemic Heart Disease: A Nationwide Cohort Study.

BACKGROUND: Little is known about the risk of ischemic heart disease (IHD) in tuberculosis (TB) survivors. METHODS: We performed a population-based retrospective cohort study using the Korean National Health Insurance Service database. TB survivors (n = 60 602) and their 1:1 age- and sex-matched controls (n = 60 602) were enrolled. Eligible participants were followed up from 1 year after their TB diagnosis to the date of an IHD event, date of death, or the end of the study period (31 December 2018), whichever came first. The risk of IHD was estimated using a Cox proportional hazards regression, and stratified analyses were performed for related factors. Among IHD events, we additionally analyzed for myocardial infarction (MI). RESULTS: During a median of 3.9 years of follow-up, 2.7% of TB survivors (1633/60 602) and 2.0% of the matched controls (1228/60 602) developed IHD, and 0.6% of TB patients (341/60 602) and 0.4% of the matched controls (223/60 602) developed MI. The overall risk of developing IHD and MI was higher in TB patients (adjusted hazard ratio [aHR] 1.21, 95% confidence interval [CI]: 1.12-1.32 for IHD and aHR 1.48, 95% CI: 1.23-1.78 for MI) than in the matched controls. Stratified analyses showed that TB survivors have an increased risk of IHD and MI regardless of income, place of residence, smoking status, alcohol consumption, physical activity, body mass index, and Charlson comorbidity index. CONCLUSIONS: TB survivors have a higher risk of IHD than matched controls. Strategies are needed to reduce the burden of IHD in TB survivors.

Associations of reproductive factors with incidence of myocardial infarction and ischemic stroke in postmenopausal women: a cohort study.

BACKGROUND: To assess the association between the reproductive factors of age at menarche, age at menopause, and reproductive span and the incidence of myocardial infarction (MI) and ischemic stroke (IS). METHODS: We used a population-based retrospective cohort study from the National Health Insurance Service database of Korea including a total of 1,224,547 postmenopausal women. Associations between age at menarche (≤ 12, 13-14 [reference], 15, 16, and ≥ 17 years), age at menopause (< 40, 40-45, 46-50, 51-54 [reference], and ≥ 55 years), and reproductive span (< 30, 30-33, 34-36, 37-40 [reference], and ≥ 41 years) and the incidence of MI and IS were assessed by Cox proportional hazard models with adjustment for traditional cardiovascular risk factors and various reproductive factors. RESULTS: During a median follow-up of 8.4 years, 25,181 MI and 38,996 IS cases were identified. Late menarche (≥ 16 years), early menopause (≤ 50 years), and short reproductive span (≤ 36 years) were linearly associated with a 6%, 12-40%, and 12-32% higher risk of MI, respectively. Meanwhile, a U-shaped association between age at menarche and risk of IS was found, with a 16% higher risk in early menarche (≤ 12 years) and a 7-9% higher risk in late menarche (≥ 16 years). Short reproductive span was linearly associated with an increased risk of MI, whereas both shorter and longer reproductive spans were associated with an increased risk of IS. CONCLUSIONS: This study demonstrated different patterns of association between age at menarche and incidence of MI and IS: a linear association for MI versus a U-shaped association for IS. Female reproductive factors in addition to traditional cardiovascular risk factors should be considered when assessing overall cardiovascular risk in postmenopausal women.

Smoking behavior change and risk of cardiovascular disease incidence and mortality in patients with type 2 diabetes mellitus.

BACKGROUND: We aimed to examine the association between smoking behavior change and risk of cardiovascular disease (CVD) incidence and mortality in patients with type 2 diabetes mellitus (T2DM). METHODS: This study used nationwide data from the Korean National Health Insurance System and included 349,137 T2DM patients who smoked. Smoking behavior changes were defined with five groups: quitters, reducers I (≥ 50% reduction), reducers II (20-50% reduction), sustainers (± 20%), and increasers (≥ 20% increase) from the number of cigarettes/day at the baseline. RESULTS: During a median follow-up of 5.1 years, 6,514 cases of myocardial infarction (MI) (1.9%), 7,837 cases of ischemic stroke (IS) (2.2%), and 14,932 deaths (4.3%) were identified. Quitters had a significantly decreased risk of MI (adjusted hazard ratio [aHR] 0.80, 95% CI 0.75-0.86) and IS (aHR 0.80, 95% CI 0.75-0.85) compared to sustainers, whereas reducers did not have a significant association with the risk of MI (aHR 1.03, 95% CI 0.94-1.13) and IS (aHR 1.00, 95% CI 0.92-1.08) in reducer I. Quitters also had a lower all-cause and CVD mortality than sustainers. CONCLUSIONS: Smoking cessation was associated with decreased CVD incidence, and all-cause and CVD mortality among T2DM patients. However, smoking reduction was not associated with decreased risks for these.

Fracture risk in Parkinson's disease according to its severity and duration.

Fracture risk was elevated in Parkinson's disease (PD) patients compared with controls in this nationwide study. Among PD patients, the risk of fracture increased linearly with PD severity, whereas no difference in fracture risk was observed according to PD duration. INTRODUCTION: Parkinson's disease (PD) is reported to be associated with a high risk of fractures. Several studies found an association between severity and duration of PD and falls or bone mineral density, but those factors have not been considered in most previous research. The aim of this study was to determine the fracture risk in PD patients according to their disease severity and duration. METHODS: This population-based, retrospective cohort study used data from the Korean National Health Insurance Service database. The study population included 10,333 patients with prevalent PD and 6,501,464 comparison cohort. Fracture risks according to the prevalence, severity, and duration of PD were evaluated using Cox proportional hazard methods. RESULTS: Fracture risk was elevated in PD patients at all sites compared with controls (adjusted hazard ratio [aHR] 1.49, 95% confidence interval [CI] 1.44-1.56 for any fracture). When comparing fracture sites, hip fractures showed the largest risk increase in PD patients (aHR 2.16, 95% CI 1.95-2.38). Among PD patients, the risk of any fracture increased linearly with PD severity and was highest in patients with severe disease (aHR 1.65, 95% CI 1.53-1.79 compared with controls). Meanwhile, no significant association was observed between PD duration and fracture risk. CONCLUSIONS: The prevalence of PD was related to an increased risk of fractures in this nationwide study, and PD severity was linearly associated with fracture risk. PD prevalence and severity should be considered when evaluating the risk factors of fracture in clinical practice.

Tuberculosis and Risk of Ischemic Stroke: A Nationwide Cohort Study.

BACKGROUND: Conflicting results exist regarding the risk of ischemic stroke in tuberculosis survivors. We aimed to estimate the risk of ischemic stroke using a nationwide population-based retrospective cohort. METHODS: We gathered data from the Korean National Health Insurance Service on tuberculosis survivors and 1:1 age- and sex-matched non-tuberculosis cases. Eligible participants were followed up from 1 year after tuberculosis diagnosis to the date of ischemic stroke event, date of death, or until the end of the study period (December 31, 2018), whichever came first. Cox proportional hazard regression and stratified analyses were performed to identify any related factors. RESULTS: During follow-up periods of 3.8 years for patients with tuberculosis and matched non-tuberculosis cases, 1.3% of patients with tuberculosis (941/72 863) and 1.0% of matched non-tuberculosis cases (707/72 863) developed ischemic stroke. The overall risk of ischemic stroke was higher in tuberculosis patients (adjusted hazard ratio: 1.22 [95% CI, 1.10-1.36]) compared with the matched non-tuberculosis cases. A stratified analysis showed that patients with tuberculosis had increased risk of ischemic stroke regardless of age, sex, smoking status, alcohol consumption, physical activity, body mass index, and Charlson Comorbidity Index score. CONCLUSIONS: Tuberculosis survivors had a higher risk of ischemic stroke than their matched non-tuberculosis cases. The results of this study suggest that tuberculosis is a crucial infectious factor associated with increased incidence of ischemic stroke.

Association of Change in Alcohol Consumption With Risk of Ischemic Stroke.

BACKGROUND: The effect of serial change in alcohol consumption on stroke risk has been limitedly evaluated. We investigated the association of change in alcohol consumption with risk of stroke. METHODS: This study is a population-based retrospective cohort study from National Health Insurance Service database of all Koreans. Four lakh five hundred thirteen thousand seven hundred forty-six participants aged ≥40 years who underwent 2 subsequent national health examinations in both 2009 and 2011. Alcohol consumption was assessed by average alcohol intake (g/day) based on self-questionnaires and categorized into non-, mild, moderate, and heavy drinking. Change in alcohol consumption was defined by shift of category from baseline. Cox proportional hazards model was used with adjustment for age, sex, smoking status, regular exercise, socioeconomic information, and comorbidities, Charlson Comorbidity Index, systolic blood pressure, and laboratory results. Subgroup analysis among those with the third examination was conducted to reflect further change in alcohol consumption. RESULTS: During 28 424 497 person-years of follow-up, 74 923 ischemic stroke events were identified. Sustained mild drinking was associated with a decreased risk of ischemic stroke (adjusted hazard ratio, 0.88 [95% CI, 0.86-0.90]) compared with sustained nondrinking, whereas sustained heavy drinking was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.06 [95% CI, 1.02-1.10]). Increasing alcohol consumption was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.11 [95% CI, 1.06-1.17] from mild to moderate; adjusted hazard ratio, 1.28 [95% CI, 1.19-1.38] from mild to heavy) compared with sustained mild drinkers. Reduction of alcohol consumption from heavy to mild level was associated with 17% decreased risk of ischemic stroke through 3× of examinations. CONCLUSIONS: Light-to-moderate alcohol consumption is associated with a decreased risk of ischemic stroke, although it might be not causal and could be impacted by sick people abstaining from drinking. Reduction of alcohol consumption from heavy drinking is associated with a decreased risk of ischemic stroke.

Effect of smoking reduction, cessation, and resumption on cancer risk: A nationwide cohort study.

BACKGROUND: The objective of this study was to investigate the effects of reduction, cessation, and resumption of smoking on cancer development. METHODS: The authors identified 893,582 participants who currently smoked, had undergone a health screening in 2009, and had a follow-up screening in 2011. Among them, 682,996 participated in a third screening in 2013. Participants were categorized as quitters, reducers I (≥50% reduction), reducers II (<50% reduction), sustainers (referent), or increasers (≥20% increase). Outcome data were obtained through December 31, 2018. RESULTS: Reducers I exhibited a decreased risk of all cancers (adjusted hazard ratio [aHR], 0.96; 95% confidence interval [CI], 0.93-0.99), smoking-related cancers (aHR, 0.95; 95% CI, 0.92-0.99), and lung cancer (aHR, 0.83; 95% CI, 0.77-0.88). Quitters had the lowest risk of all cancers (aHR, 0.94; 95% CI, 0.92-0.96), smoking-related cancers (aHR, 0.91; 95% CI, 0.89-0.93), and lung cancer (aHR, 0.79; 95% CI, 0.76-0.83). In further analysis with 3 consecutive screenings, additional smoking reduction (from reducers II to reducers I) lowered the risk of lung cancer (aHR, 0.74; 95% CI, 0.58-0.94) in comparison with sustainers. Quitting among reducers I further decreased the risk of all cancers (aHR, 0.90; 95% CI, 0.80-1.00), smoking-related cancers (aHR, 0.81; 95% CI, 0.81-0.92), and lung cancer (aHR, 0.66; 95% CI, 0.52-0.84) in comparison with sustainers. Smoking resumption after quitting, even at a lower level, increased the risk of smoking-related cancers (aHR, 1.19; 95% CI, 1.06-1.33) and lung cancer (aHR, 1.48; 95% CI, 1.21-1.80) in comparison with sustained quitting. CONCLUSIONS: Smoking cessation and, to a lesser extent, smoking reduction decreased the risks of cancer. Smoking resumption increased cancer risks in comparison with sustained quitting. LAY SUMMARY: Worldwide, tobacco use is the single leading preventable risk factor for cancer and cancer death. This study examined the effects of reduction, cessation, and resumption of smoking on cancer development by measuring smoking behavior repetitively. Although smoking reduction has a substantial cancer prevention benefit for those who cannot quit, cessation should be encouraged whenever possible. Quitters should be monitored to ensure that they do not resume smoking.

Conditional Survival of Patients Who Underwent Curative Resection for Esophageal Squamous Cell Carcinoma.

OBJECTIVE: To analyze conditional survival estimates of patients with esophageal cancer who underwent curative resection. SUMMARY BACKGROUND DATA: Conditional survival reflects dynamic prognosis updated to the current status and is a more relevant indicator for current healthcare and life decisions. METHODS: This study included 1883 patients who underwent complete resection for esophageal squamous cell carcinoma at a tertiary cancer center from 1994 to 2016. We calculated 5-year (5Y) conditional overall survival (COS), conditional recurrence-free survival (CRFS), and conditional relative survival (CRS) estimates from diagnosis to 5 years of survival. RESULTS: The 5Y COS, CRFS, and CRS increased from 63.7%, 65.2%, and 70.2% at diagnosis to 75.8%, 91.9%, and 86.4 at 5 years after diagnosis, respectively. While there were large differences with different stages (stage I, II, III) at diagnosis (81.2%, 64.9%, and 37.3% for COS; 85.1, 65.1%, and 67.9% for CRFS; 89.2%, 72.1%, and 41.1% for CRS), the gap decreased with time; rates were similar after 5 years (77.1%, 75.7%, and 72.6% for COS; 91.7%, 90.6%, and 94.5% for CRFS, and 89.3%, 85.4%, and 78.3% in CRS, respectively). The 5Y COS, CRFS, and CRS were persistently lower in older patients even after 5 years. CONCLUSIONS: Conditional survival estimates generally increase over time, and the largest improvements were observed for patients with advanced stage. Availability of updated prognosis at various time points allows clinicians to better guide their patients. Our results also imply substantial residual risk of recurrence and sustained excess mortality compared to the general population even after 5 years.

Conditional relative survival and competing mortality in patients who underwent surgery for lung cancer: A nationwide cohort study.

We aimed to investigate the conditional relative survival (CRS) and competing mortality in patients who underwent surgery for newly diagnosed lung cancer. Using a nationwide population-based database, we calculated 5-year CRS on 1 to 5 years survival after surgery. These rates were reported according to age, sex, socioeconomic status, comorbidities and treatment received. We also estimated cause-specific mortality with the consideration of competing risk. We identified 34 349 patients newly diagnosed with primary lung cancer from 2007 to 2013. The 5-year CRS after surgery was 71.7% at baseline improving steadily to 85.4% by 5 years, suggesting evidence of persistent excess mortality risk. Throughout the period, lung cancer was the most common cause of death, contributing to 83.6% mortality 1 year after surgery and 66.3% 5 years after surgery. Other causes of death included cardiovascular disease and respiratory disease, which increased continuously with time after surgery. CRS rates for patients with lung cancer improved over time but did not reach the level of the general population even 5 years after surgery. Although the main cause of death continues to be lung cancer, death from noncancer causes increased with time after surgery. Evidence-based decisions could be made on the dynamic risk profiles of the patients.

Obesity and breast cancer risk for pre- and postmenopausal women among over 6 million Korean women.

PURPOSE: To examine the association between obesity measured by body mass index (BMI) and waist circumference (WC) according to menopausal status in Korean women. METHODS: We identified 6,467,388 women, using the Korean National Health Insurance System Cohort. Cox-proportional hazard models were used to generate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for breast cancer risk in relation to BMI and WC. RESULTS: In postmenopausal women, the risk of breast cancer increased with BMI. Compared to women with a BMI of 18.5-23 kg/m two, the risk of invasive breast cancer was lower in patients with BMI < 18.5 (aHR 0.82, 95% CI 0.75-0.89), while it increased linearly in those with BMI 23-25 (1.11, 1.08-1.14), BMI 25-30 (1.28, 1.25-1.32), and BMI ≥ 30 (1.54,1.47-1.62). In contrast, the risk of breast cancer decreased with BMI in premenopausal women. Compared to women with a BMI of 18.5-23, the risk of IBC was similar in those with a BMI < 18.5 (1.02, 0.94-1.11) and BMI 23-25 (1.01, 0.97-1.05), but was significantly lower in those with a BMI 25-30 (0.95, 0.91-0.98) and BMI ≥ 30 (0.90, 0.82-0.98). A relative increase with BMI was less profound for carcinoma in situ in postmenopausal women, and a relative decrease was more profound in premenopausal women. An analysis using WC showed almost identical results. CONCLUSIONS: There was a positive relationship between obesity and breast cancer in postmenopausal women, and an inverse association in premenopausal women.

Association between obesity and the risk of gastric cancer in premenopausal and postmenopausal women: A nationwide cohort study.

BACKGROUND AND AIM: Obesity was suggested to increase the incidence of gastric cancer (GC) in women, but results from previous studies were inconsistent. We investigated the relationship between obesity and the risk of GC according to menopausal status. METHODS: We enrolled 1 418 180 premenopausal and 4 854 187 postmenopausal women aged ≥ 40 years using the Korean National Health Insurance System Cohort (2009-2014). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for GC incidence according to body mass index (BMI) and waist circumference (WC) using the Cox proportional hazards models. RESULTS: During the mean follow-up period of 7.2 years, 42 441 women were newly diagnosed with GC. Compared with the group with BMI 18.5-22.9 kg/m2 , the adjusted HRs (95% CIs) for GC in the groups with BMI < 18.5, 23-24.9, 25-29.9, and ≥ 30 kg/m2 were 1.12 (0.95-1.33), 0.96 (0.89-1.04), 1.02 (0.94-1.11), and 0.99 (0.83-1.18), respectively, for premenopausal women and 1.07 (1.00-1.14), 1.01 (0.99-1.04), 1.03 (1.00-1.05), and 1.11 (1.10-1.16), respectively, for postmenopausal women. Compared with the group with WC 65-74.9 cm, the adjusted HRs (95% CIs) for GC for the groups with WC < 65, 75-84.9, 85-94.9, and ≥ 90 cm were 1.00 (0.88-1.15), 1.03 (0.96-1.11), 1.10 (0.99-1.22), and 1.02 (0.81-1.27), respectively, for premenopausal women and 1.01 (0.94-1.09), 1.01 (0.99-1.04), 1.09 (1.06-1.13), and 1.14 (1.09-1.19), respectively, for postmenopausal women. CONCLUSIONS: We found a positive association between the highest BMI and WC category and risk of GC in postmenopausal women; however, such an association was not evident in premenopausal women.

FEMALE REPRODUCTIVE FACTORS AND THE RISK OF EXUDATIVE AGE-RELATED MACULAR DEGENERATION: A Nationwide Cohort Study.

PURPOSE: To evaluate the association between female reproductive factors and the incidence of exudative age-related macular degeneration (AMD). METHODS: A total of 1,297,388 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2009 were identified using the Korea National Health Insurance System database. Data on female reproductive factors were collected using a self-administered questionnaire. Patients were followed up until 2018, and the incident cases of exudative AMD were identified. The hazard ratios and 95% confidence intervals for exudative AMD were estimated using the multivariable-adjusted Cox proportional hazard model. RESULTS: During a mean follow-up of 7.27 years, 4,086 patients were newly diagnosed with exudative AMD. The hazard ratio (95% confidence intervals) for exudative AMD was 1.14 (1.01-1.31) for a reproductive period ≥40 years compared with a reproductive period <30 years, 1.72 (1.48-2.00) for patients with ≥5 years of hormone replacement therapy, and 1.29 (1.09-1.52) for those with 2 to 5 years of hormone replacement therapy compared with those who never underwent hormone replacement therapy. CONCLUSION: Female reproductive factors were associated with the risk of exudative AMD. Greater lifetime exposure to endogenous and exogenous estrogen was associated with a higher incidence of exudative AMD.

Association between physical performance and incidence of end-stage renal disease in older adults: a national wide cohort study.

BACKGROUND: Physical frailty has previously been associated with adverse clinical outcomes in patients with end-stage renal disease (ESRD). This study aimed to determine whether impaired physical performance at baseline is associated with the incidence of ESRD, using a nationwide database. METHODS: The timed up-and-go (TUG) test was used to assess physical frailty in 1,552,781 66-year-old individuals, using health examination database records from the Korean National Health Insurance Service. As a primary endpoint, incident ESRD was defined operationally using healthcare claims data from the Korean Health Insurance Review and Assessment Service. RESULTS: Our results showed that baseline kidney function was significantly worse in individuals with TUG results of > 10 s compared to individuals with an intact TUG performance (≤10 s). Kaplan-Meier analysis showed a stepwise dose-response relationship between baseline physical performance and the incidence rate of ESRD (log-rank test P-value of < 0.001). An increasing ESRD incidence rate trend with poor physical performance remained significant after adjusting for characteristics such as baseline glomerular filtration rate and proteinuria. CONCLUSION: Poor baseline physical performance was associated with an increased risk of ESRD, suggesting possible interactions between systemic frailty and vascular aging processes.

Breast cancer screening disparities between women with and without disabilities: A national database study in South Korea.

BACKGROUND: Health disparities among individuals with disabilities remain underrecognized. The objective of the current study was to investigate: 1) whether disparities exist in breast cancer screening rates among women with disabilities compared with women without disabilities; 2) whether breast cancer screening rates vary according to the type and severity of disabilities; and 3) trends in breast cancer screening disparities according to disability status over time. METHODS: Using national administrative databases concerning disability status and national cancer screening programs in Korea, age-standardized participation rates were calculated according to the type and severity of disabilities. RESULTS: The age-standardized rate for breast cancer screening in individuals with disabilities increased from 30.2% in 2006 to 53.7% in 2015 (change of +23.5%), whereas that among those without a disability increased from 29.3% to 60.1% (change of +30.8%). In general, disability was associated with slightly lower breast cancer screening rates (adjusted odds ratio [aOR], 0.824; 95% CI, 0.820-0.828). However, screening rates were especially low in women with severe disabilities (aOR, 0.465; 95% CI, 0.461-0.469) and among women with autism (aOR, 0.235; 95% CI, 0.143-0.388), renal failure (aOR, 0.342; 95% CI, 0.337-0.348), brain injury (aOR, 0.349; 95% CI, 0.346-0.352), intellectual disabilities (aOR, 0.403; 95% CI, 0.397-0.410), mental disorders (aOR, 0.494; 95% CI, 0.488-0.501), or ostomies (aOR, 0.529; 95% CI, 0.512-0.546). CONCLUSIONS: Even without a cost barrier, significant disparities were found in breast cancer screening participation, especially in women with severe disabilities and brain-related and/or mental disabilities. Policy efforts, such as ensuring the accessibility of information and equipment, transportation support, and access to a usual source of care, should be made to decrease this disparity.

Female reproductive factors and the risk of lung cancer in postmenopausal women: a nationwide cohort study.

BACKGROUND: Reproductive factors and hormone use in postmenopausal women have been hypothesised to affect the risk of developing lung cancer, but the epidemiological evidence is inconsistent. METHODS: Using the Korean National Health Insurance System database, we identified 4,775,398 postmenopausal women older than 40 years who had undergone both cardiovascular health- and cancer screening between 1 January 2009 and 31 December 2014. Information about reproductive factors was obtained from a self-administered questionnaire. The risk of lung cancer was estimated using Cox proportional hazard regression models. RESULTS: During a median follow-up of 4.4 years, 16,556 women (15,223 non-smokers) were diagnosed with lung cancer. The risk of lung cancer was not significantly influenced by early menarche age (adjusted hazard ratio [aHR] 1.03 for menarche ≥18 vs. ≤14; 95% confidence interval [CI], 0.98-1.09) or late age at menopause (aHR 1.02 for menopause ≥55 vs. <40; 95% CI, 0.91-1.14). Furthermore, the number of children, duration of breastfeeding and use of hormone replacement therapy were not associated with the risk of lung cancer. CONCLUSIONS: No statistically significant association was found between reproductive factors and the risk of lung cancer in postmenopausal Korean women.

Health behaviors of caregivers of childhood cancer survivors: a cross-sectional study.

BACKGROUND: Caregiving for childhood cancer survivors may be burdensome for caregivers and affect their physical health and health behaviors. However, studies examining health behaviors in caregivers of childhood cancer survivors are scarce. This study aimed to examine health behaviors of caregivers of childhood cancer survivors by comparing them with those of the general population, and analyze associated factors. METHODS: This study included 326 caregivers of childhood cancer survivors recruited from 3 major hospitals in South Korea and 1304 controls from the Korean National Health and Nutritional Examination Survey matched for age, sex, and education level. We compared health behaviors between the two groups by using conditional logistic regression analyses, and investigated factors associated with unhealthy behaviors in caregivers by using multiple logistic regression analyses. RESULTS: Caregivers were less likely to be physically inactive (aOR: 0.69, 95% CI: 0.51, 0.92) compared to controls, and this was more evident in women (aOR: 0.65, 95% CI: 0.45, 0.94). However, caregivers were more likely to be binge drinkers (aOR: 2.26, 95% CI: 1.73, 2.97), especially if they were men (aOR: 13.59, 95% CI: 8.09, 22.82). Factors associated with unhealthy behaviors in caregivers differed by the type of behavior. Current smoking risk was lower in female caregivers and in those with more comorbidities. Increasing age, female sex, higher education level, and lower household income were associated with lower risk of binge drinking. Higher household income and anxiety were associated with lower risk of physical inactivity, while depression was associated with higher risk of physical inactivity. CONCLUSIONS: Caregivers of childhood cancer survivors were more likely to engage in binge drinking, but less likely to be physically inactive. Strategies to promote adherence to desirable health behaviors in caregivers are needed with consideration of their socioeconomic and clinical factors, such as number of comorbidities.

Timed Up and Go Test and the Risk of Parkinson's Disease: A Nation-wide Retrospective Cohort Study.

BACKGROUND: If mild parkinsonian signs can be a marker for Parkinson's disease (PD) development, an impaired Timed Up and Go test (TUG) should also be a marker for prodromal PD. OBJECTIVES: To investigate whether the Timed Up and Go test is associated with PD. METHODS: We included 1,196,614 participants at 66 years of age who underwent the National Screening Program for Transitional Ages for Koreans between 2009 and 2014. Timed Up and Go test times were classified into <10 and ≥10 seconds. Incidence of PD was defined using claims data. RESULTS: During the median follow-up period of 3.5 years, participants with slow Timed Up and Go test time had significantly increased risk of developing PD compared with those with normal Timed Up and Go test time (adjusted hazard ratio: 1.28; 95% confidence interval: 1.20-1.37). Furthermore, participants with an abnormal Timed Up and Go test result, defined as ≥20 seconds, had a significantly increased risk of PD compared with those with a normal Timed Up and Go test result (adjusted hazard ratio: 2.18; 95% confidence interval: 1.63-2.92). CONCLUSION: An indicator of subtle motor deficits, the Timed Up and Go test could be a prodromal marker for the risk of PD development. © 2020 International Parkinson and Movement Disorder Society.

Female reproductive factors and the risk of Parkinson's disease: a nationwide cohort study.

There are conflicting finds in the literature regarding the association of female estrogen status and the incidence of Parkinson's disease (PD). We aimed to investigate whether female reproductive factors are associated with PD. Using the Korean National Health Insurance System database, 4,729,546 postmenopausal women without PD were identified. The new incidence of PD was defined as subjects with an ICD-10 code for PD (G20) and with a rare intractable disease registration code for PD (V124). The Cox proportional hazard models were used to evaluate the associations of various reproductive factors with incidence of PD. During the median follow-up of 5.84 years, 20,816 individuals were diagnosed with PD. An increased risk of PD was observed in subjects with a later age at menarche (≥ 17 years) compared with reference subjects (13 years ≤ age at menarche ≤ 14 years) (adjusted hazard ratio, aHR 1.10, 95% confidence interval, CI 1.05-1.16). As age at menopause increased, risk of PD decreased (P for trend 0.019). Consistently, decreased risk of PD was observed (aHR 0.91, 95% CI 0.85-0.96) in subjects with longer duration of fertility (≥ 40 years of age) compared with shorter duration of fertility (< 30 years of age). Hormone replacement therapy and oral contraceptives independently increased the risk of PD by 17% and 7%, respectively. Female reproductive factors are independent risk factors for PD, with higher risk associated with shorter lifetime exposure to endogenous estrogen.