The associations of previous influenza/upper respiratory infection with COVID-19 susceptibility/morbidity/mortality: a nationwide cohort study in South Korea.

We aimed to investigate the associations of previous influenza/URI with the susceptibility of COVID-19 patients compared to that of non-COVID-19 participants. A nationwide COVID-19 cohort database was collected by the Korea National Health Insurance Corporation. A total of 8,070 COVID-19 patients (1 January 2020 through 4 June 2020) were matched with 32,280 control participants. Severe COVID-19 morbidity was defined based on the treatment histories of the intensive care unit, invasive ventilation, and extracorporeal membrane oxygenation and death. The susceptibility/morbidity/mortality associated with prior histories of 1-14, 1-30, 1-90, 15-45, 15-90, and 31-90 days before COVID-19 onset were analyzed using conditional/unconditional logistic regression. Prior influenza infection was related to increased susceptibility to COVID-19 (adjusted odds ratio [95% confidence interval] = 3.07 [1.61-5.85] for 1-14 days and 1.91 [1.54-2.37] for 1-90 days). Prior URI was also associated with increased susceptibility to COVID-19 (6.95 [6.38-7.58] for 1-14 days, 4.99 [4.64-5.37] for 1-30 days, and 2.70 [2.55-2.86] for 1-90 days). COVID-19 morbidity was positively associated with influenza (3.64 [1.55-9.21] and 3.59 [1.42-9.05]) and URI (1.40 [1.11-1.78] and 1.28 [1.02-1.61]) at 1-14 days and 1-30 days, respectively. Overall, previous influenza/URI did not show an association with COVID-19 mortality. Previous influenza/URI histories were associated with increased COVID-19 susceptibility and morbidity. Our findings indicate why controlling influenza/URI is important during the COVID-19 pandemic.

Mortality and Cause of Death in Hearing Loss Participants: A Longitudinal Follow-up Study Using a National Sample Cohort.

OBJECTIVE: The purpose of the present study was to estimate the risk of mortality in hearing loss subjects in accordance with the cause of death. STUDY DESIGN: A longitudinal follow up study. SETTING: Data from the Korean National Health Insurance Service-National Sample Cohort were collected from a period between 2002 and 2013. PATIENTS AND INTERVENTION: The 4,606 severe and 1,007 profound hearing loss participants with 40 or more years old were 1:4 matched with control participants, respectively, for age, sex, income, and region of residence. The causes of death were grouped into 12 classifications. MAIN OUTCOME MEASURES: The ratio of mortality was compared between the hearing loss and control group using a χ test or Fisher's exact test. In a Cox-proportional hazard model, age, sex, income, region of residence, and past medical histories were considered confounders. RESULTS: The severe and profound hearing loss groups showed 4.07 (95% CI = 3.71-4.46, p < 0.001) and 4.22 times (95% CI = 3.52-5.05, p < 0.001) higher mortality ratios in the adjusted models, respectively. Both the severe and profound hearing loss groups showed higher mortality by infection, neoplasm, trauma, and metabolic, mental, circulatory, respiratory, and digestive diseases than control groups (p < 0.05). Among various causes of death, death by trauma revealed the highest odds ratios in both the severe and profound hearing loss groups. CONCLUSION: Hearing loss was associated with a significant increase in mortality.

Mortality and Cause of Death in Patients With Vertebral Fractures: A Longitudinal Follow-Up Study Using a National Sample Cohort.

STUDY DESIGN: A retrospective study using the Korean Health Insurance Review and Assessment Service-National Sample Cohort was performed. OBJECTIVE: To determine the rate and causes of mortality in vertebral fracture patients. SUMMARY OF BACKGROUND DATA: Vertebral fractures are associated with increased mortality in prior studies. METHODS: Of 1,125,691 patients, we collected data of 23,026 patients of all ages who experienced thoracic or lumber vertebral fractures between 2002 and 2013. The vertebral fracture participants were matched 1:4 with control participants, accounting for age, group, sex, income, and region of residence. Finally, 21,759 vertebral fracture participants and 87,036 control participants were analyzed. The index date was the date of diagnosis of vertebral fracture; participants from the control group were followed from the same index date as their matched counterparts. The follow-up duration was the index date to the death date or the last date of study (December 31, 2013). Patients were followed until death or censoring of the data. Death was ascertained in the same period, and causes of death were grouped into 12 classifications according to the Korean Standard Classification of Disease. A stratified Cox proportional hazards model was used. RESULTS: The adjusted hazard ratio (HR) for mortality of vertebral fracture was 1.28 (P < 0.001) with the higher adjusted HR in younger patients. Mortalities caused by neoplasms; neurologic, circulatory, respiratory, digestive, and muscular diseases; and trauma were higher in the vertebral fracture group (P < 0.05), with muscular disease showing the highest odds ratio for mortality. CONCLUSION: Vertebral fractures were associated with increased mortality in Korean. Disease in muscuoskeletal system and connective tissue that possibly be associated with the fractures was most responsible for elevated death rates following vertebral fracture. Our findings may help caregivers provide more effective care, ultimately decreasing the mortality rate of vertebral fracture patients. LEVEL OF EVIDENCE: 3.

Mortality and cause of death in South Korean patients with Parkinson's disease: a longitudinal follow-up study using a national sample cohort.

OBJECTIVE: The incidence rate of Parkinson's disease (PD) is growing rapidly owing to the ageing population. We investigated the mortality rates and causes of death in South Korean patients with PD. DESIGN: We investigated a national cohort using the nationwide insurance database. SETTING: Korean Health Insurance Review and Assessment Service-National Sample Cohort database. PARTICIPANTS: We included 3510 participants ≥60 years of age who were diagnosed with PD between 2002 and 2013, as well as 14 040 matched controls. INTERVENTIONS: None PRIMARY AND SECONDARY OUTCOME MEASURES: A stratified Cox proportional hazards model was used to evaluate patients with PD who were matched 1:4 with non-PD control subjects adjusted for age, sex, income and region of residence. The causes of death were grouped into 12 classifications. RESULTS: The adjusted HR for mortality in the PD group was 2.09 (95% CI 1.94 to 2.24, p<0.001). Subgroup analysis according to age (<70 years, 70-79 years, and ≥80 years) and sex revealed that patients with PD showed higher adjusted HRs for mortality across all subgroups. Mortalities caused by metabolic, mental, neurologic, circulatory, respiratory, and genitourinary diseases, as well as trauma, were more common in the PD group than in the control group, with the highest OR observed in patients with neurologic disease. CONCLUSIONS: We demonstrated that PD in South Korean patients ≥60 years of age was associated with increased mortality in both sexes regardless of age.

Association between Herpes Zoster and Osteoporosis: A Nested Case-Control Study Using a National Sample Cohort.

OBJECTIVES: Chronic inflammatory disease might affect osteoporosis; however, few studies have reported the association between herpes zoster and osteoporosis. The goal of this study was to estimate the association between herpes zoster and osteoporosis in Korean residents. METHODS: The Korean National Health Insurance Service-National Sample Cohort, which includes individuals aged ≥ 50 years, was assessed from 2002 to 2013. In total, 68,492 osteoporosis participants were matched with 68,492 control participants at a ratio of 1:1 by age, sex, income, and region of residence. We assayed the prior histories of herpes zoster in the osteoporosis and control groups. The diagnoses of herpes zoster and osteoporosis were based on ICD-10 codes and claim codes. Crude and adjusted models of odds ratios (ORs) were explored using conditional logistic regression analyses, and the 95% confidence intervals (CIs) were computed. The participants were stratified according to age, sex, income, and region of residence. Subgroup analyses were performed to investigate the role of age and sex. RESULTS: The rate of herpes zoster in the osteoporosis group (5.1% [3,487/68,492]) was higher than that in the control group (4.0% [2,738/68,492]). The adjusted OR of herpes zoster in the osteoporosis group was 1.17 (95% CI = 1.11-1.24). In the subgroup analyses, the adjusted OR was 1.34 (95% CI = 1.01-1.78) among males aged < 65 years, 1.20 (95% CI = 1.12-1.29) among females aged < 65 years, and 1.19 (95% CI = 1.04-1.36) among males aged ≥ 65 years. CONCLUSION: The ORs of herpes zoster were increased among the osteoporosis patients. This correlation was reliable in all subgroups by age and sex except group of women ≥ 65 years old.

Increased risk of Bell palsy in patient with migraine: A longitudinal follow-up study.

Migraine is thought to be associated with Bell palsy. This study aimed to investigate the risk of Bell palsy in migraine patients.The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. A total of 45,164 migraine patients were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia and compared with 180,656 controls. The migraine group included participants diagnosed with migraine [International Classification of Disease (ICD)-10: G43] who underwent treatment more than once. Participants with Bell palsy were included on the basis of the ICD-10 (G510) and treatment with steroids. A history of hypertension, diabetes, and dyslipidemia was determined using ICD-10 codes. Crude (simple) and adjusted hazard ratios (HRs) of Bell palsy in migraine patients were analyzed using the Cox proportional hazards model. Subgroup analyses were conducted based on age and sex.Bell palsy occurred in 0.6% (262/44,902) of the migraine group and 0.5% (903/179,753) of the control group. The adjusted HR of Bell palsy was 1.16 in the migraine group compared with the control group [95% confidence interval (95% CI) = 1.01-1.33, P = .34]. Among age-related subgroups, participants ≥30 and <60 years old in the migraine subgroup demonstrated a 1.28-times higher risk of Bell palsy than the control group (95% CI = 1.05-1.57, P = .014).Migraine increased the risk of Bell palsy in the total population. Among age subgroups, migraine patients ≥30 and <60 years old had an increased risk of Bell palsy.

Increased risk of migraine in patients with psoriasis: A longitudinal follow up study using a national sample cohort.

Both psoriasis and migraine are associated with inflammatory diseases. However, few studies have been conducted the increased risk of migraine in psoriasis patients. The aim of this study was to identify whether the psoriasis increases the risk of migraine. This study used the national cohort study data collected by the Korean Health Insurance Review and Assessment from 2002 to 2013. Patients with psoriasis (n = 11,071) and control participants (n = 44,284) were selected and matched 1:4 by age, sex, income, region of residence, and past medical history of hypertension, diabetes, and dyslipidemia. This study used Cox-proportional hazard model for calculating hazard ratio (HR) with crude and adjusted model. Stratification by age and sex was analyzed. Migraines occurred significantly more frequently in psoriasis patients than in control participants (adjusted HR = 1.16, 95% confidence interval (CI) = 1.04-1.31, P <.05). In the stratification analysis, migraines occurred significantly more frequently in psoriasis patients than in control participants only in the group of middle-aged males (adjusted HR = 1.62 95% CI = 1.22-2.13, P = .001). In conclusion, psoriasis might increase the risk of migraine.

Sudden Sensorineural Hearing Loss Predicts Ischemic Stroke: a Longitudinal Follow-Up Study.

OBJECTIVES: To investigate the risk of stroke in SSNHL patients. STUDY DESIGN: A longitudinal follow-up cohort study. SETTING: The Korean National Health Insurance Service-National Sample Cohort from 2002 to 2013. PATIENTS: The 4,944 SSNHL participants were matched with 19,776 controls for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia. The SSNHL subjects were diagnosed (International Classification of Disease [ICD]-10: H91.2), underwent an audiometry examination, and were treated with steroids. The history of hemorrhagic stroke, ischemic stroke, hypertension, diabetes, dyslipidemia, ischemic heart disease, and depression was investigated based on the ICD-10. MAIN OUTCOME MEASURES: The hazard ratios (HRs) for hemorrhagic and ischemic stroke were analyzed using a Cox proportional hazard model. Subgroup analyses were conducted according to age (< 50 vs. ≥ 50 yr old) and sex. RESULTS: Participants diagnosed with ischemic stroke included 4.2% of SSNHL subjects and 3.5% of control subjects (p = 0.013). The adjusted HR of SSNHL for ischemic stroke was 1.22 (95% confidence interval [95% CI] = 1.05 - 1.43, p = 0.012). The ≥ 50-year-old male SSNHL subgroup showed 1.40 adjusted HRs for ischemic stroke (95% CI = 1.10 - 1.78, p = 0.006). The rate of hemorrhagic stroke was 0.7% for SSNHL and 0.6% for control subjects. SSNHL did not elevate the risk of hemorrhagic stroke (p = 0.310). CONCLUSION: SSNHL elevated the risk of ischemic stroke in the general population. Older males with SSNHL demonstrated a high risk for ischemic stroke; however, SSNHL did not increase the risk of hemorrhagic stroke.

The association between sleep duration, sleep quality, and food consumption in adolescents: A cross-sectional study using the Korea Youth Risk Behavior Web-based Survey.

OBJECTIVE: This study examined the relationship between sleep duration, sleep quality and food consumption among adolescents. DESIGN: Cross-sectional study. SETTING: Data from the 2014 and 2015 Korea Youth Risk Behavior Web-based Survey were used. PARTICIPANTS: Participants aged 12-18 years (n=118 462 (59 431 males and 59 031 females)) were selected. PRIMARY AND SECONDARY OUTCOME MEASURES: Sleep duration, sleep quality and the frequencies of fruits, soda, soft drinks, fast food, instant noodle, confectionaries, vegetables and milk consumption. RESULTS: Short sleep durations (<6 hours) were associated with higher soft drinks and confectionaries intake than longer sleep durations (9+ hours) (adjusted ORs (AORs) (95% CIs) for ≥5 times a week for soft drinks: 1.73 (1.57 to 1.91) and confectionaries: 1.32 (1.20 to 1.46); p<0.001). Poor sleep quality, with 7-8 hours of sleep, was associated with a lower intake of fruits, vegetables and milk (AORs (95% CIs) for ≥5 times a week for fruits: 0.71 (0.65 to 0.77); vegetables: 0.66 (0.58 to 0.75); and milk: 0.80 (0.74 to 0.86); each p<0.001), and higher intake of soda, soft drinks, fast food, instant noodle and confectionaries (AORs (95% CIs) for ≥5 times a week for soda: 1.55 (1.40 to 1.70); soft drinks: 1.58 (1.43 to 1.73); fast food: 1.97 (1.65 to 2.35); instant noodle: 1.55 (1.37 to 1.76); and confectionaries: 1.30 (1.18 to 1.43); each p<0.001) than good sleep quality of the same duration. CONCLUSION: Short sleep durations and poor sleep quality might be associated with higher consumption of unhealthier foods, such as sugar-sweetened beverages, fast food, instant noodle and confectionaries, and associated with lower consumption of fruits, vegetables and milk.

Active and passive smoking impacts on asthma with quantitative and temporal relations: A Korean Community Health Survey.

This study aimed to evaluate the relations of smoking with asthma and asthma-related symptoms, considering quantitative and temporal influences. The 820,710 Korean adults in the Korean Community Health Survey in 2009, 2010, 2011, and 2013 were included and classified as non-smoker, past smoker or current smoker. Total smoking years, total pack-years, and age at smoking onset were assessed. Information on wheezing, exercise wheezing, and aggravation of asthma in the past 12 months and asthma diagnosis history and current treatment was collected. Multiple logistic regression analysis with complex sampling was used. Current and former smokers showed significant positive relations with wheezing, exercise wheezing, asthma ever, current asthma, and asthma aggravation. Current smokers demonstrated higher adjusted odd ratios (AORs) for wheezing, exercise wheezing, and asthma aggravation than former smokers. Former smokers showed higher AORs than current smokers for current asthma treatment. Longer passive smoking was related to wheezing and exercise wheezing. Greater age at smoking onset and duration since cessation were negatively related to wheezing, exercise wheezing, and current asthma; total pack-years demonstrated proportional associations with these symptoms. Former, current, and passive smoking was positively correlated with wheezing and exercise wheezing. Total pack-years and early initiation were increasingly related to asthma.

Lack of evidence that nephrolithiasis increases the risk of sialolithiasis: A longitudinal follow-up study using a national sample cohort.

OBJECTIVE: The objective of this study was to evaluate the risk of sialolithiasis in nephrolithiasis patients. METHODS: Using data from the national cohort study from the Korean Health Insurance Review and Assessment Service, we selected 24,038 patients with nephrolithiasis. The control group consisted of 96,152 participants without nephrolithiasis who were matched 1:4 by age, sex, income, region of residence, diabetes, hypertension, and dyslipidemia. The incidence of sialolithiasis in the two groups was compared, with a follow-up period of up to 12 years. The crude and adjusted hazard ratio (HR) of nephrolithiasis to sialolithiasis was analyzed with a Cox-proportional hazard regression model. RESULTS: The rates of sialolithiasis in the nephrolithiasis group and the control group were not significantly different (0.08% vs. 0.1%, P = 0.447). The crude and adjusted hazard ratios of nephrolithiasis to sialolithiasis were not statistically significant (crude HR = 0.82, 95% confidence interval [CI] = 0.50-1.35, P = 0.448; adjusted HR = 0.81, 95% CI = 0.49-1.33, P = 0.399). Subgroup analyses according to age and sex also failed to reveal statistical significance. CONCLUSION: There is no evidence of an increased risk of sialolithiasis associated with nephrolithiasis. We suggest that routine evaluation for sialolithiasis in all patients with nephrolithiasis is not necessary.

Hearing impairment increases the risk of distal radius, hip, and spine fractures: A longitudinal follow-up study using a national sample cohort.

OBJECTIVE: Hearing impairment has been suggested to increase the risk of falls. However, most previous studies were conducted in an older population without classification of the fracture regions. This study aimed to delineate the risk of each fracture type in all age populations. METHODS: The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. A total of 4,854 severe hearing-impaired and 1,354 profound hearing-impaired participants were matched for age, group, sex, income group, and region of residence with 19,416 and 5,416 control participants, respectively. The fracture diagnosis was based on the International Classification of Disease (ICD-10) codes as follows: distal radius fracture (S525), hip fracture (S720, S721, S722), and spine fracture (S220, S32). Crude (simple) and adjusted hazard ratios (HRs) for each fracture associated with severe or profound hearing impairment were analyzed using the Cox proportional hazard model. RESULTS: The severe hearing-impaired group had an increased risk of distal radius fracture, hip fracture, and spine fracture compared with the control group (adjusted HR = 1.67, 95% CI = 1.38-2.03, P < 0.001 for hip fracture). The profound hearing-impaired group had an increased risk of hip and spine fracture (adjusted HR = 2.21, 95% CI = 1.44-3.39, P < 0.001 for hip fracture). CONCLUSION: The risk of distal radius fracture, hip fracture, and spine fracture was increased in the severe hearing-impaired group compared with the control group.

Sudden sensory neural hearing loss is not predictive of myocardial infarction: A longitudinal follow-up study using a national sample cohort.

The aim of this study was to evaluate the risk of myocardial infarction (MI) in SSNHL subjects with differently matched control groups. The Korean Health Insurance Review and Assessment Service - National Sample Cohort recruited subjects from 2002 to 2013. We used two study designs. In study I, we matched 4,467 SSNHL participants with a control group (17,868 subjects with no history of SSNHL) based on demographic factors (age, sex, income, and region of residence) and medical history (diabetes, dyslipidemia, and hypertension). In study II, we matched 4,467 SSNHL participants with a control group based on only demographic factors. The crude (simple) and adjusted hazard ratios (HRs) of SSNHL with MI were analyzed using the Cox-proportional hazard model. In study I, SSNHL was not associated with increased risk of MI. However, in study II, SSNHL was associated with increased risk of MI (adjusted HR = 1.39 95% CI = 1.00-1.93, P = 0.048). The SSNHL group did not exhibit increased risk of MI when compared to the control group matched by both demographic factors and medical history. However, compared to the control group not matched by medical history, the relative risk of MI was increased in the SSNHL group.

Active, passive, and electronic cigarette smoking is associated with asthma in adolescents.

The present study investigated the associations of active, passive, and electronic cigarette (E-cigarette) smoking with asthma in Korean adolescents. We used the cross-sectional study of Korea Youth Risk Behavior Web-based Survey conducted in 2011, 2012 and 2013. Active smoking was classified into 4 groups (0 days, 1-5 days, 6-19 days, and ≥20 days a month). Passive smoking was also categorized into 4 groups (0 days, 1-2 days, 3-4 days, and ≥5 days a week). E-cigarette was defined as yes or no in the last 30 days. Age, sex, obesity, region of residence, economic level, and parental educational level were adjusted for as confounders. Smoking variables were adjusted for one another. Adjusted odd ratios (AORs) and 95% confidence intervals (CIs) were calculated using multiple logistic regression analysis with complex sampling. In total, 2.3% (4,890/216,056) of participants reported asthma in the past 12 months. Active smoking was significantly associated with asthma (AOR [95% CI] of smoking ≥20 days/month = 1.57 [1.38-1.77], P < 0.001). Passive smoking was also related with asthma (AOR [95% CI] of smoking ≥5 days/week = 1.40 [1.28-1.53], P < 0.001). E-cigarette showed positive relation with asthma, although the effects of past smoking history could not be excluded (AOR [95% CI] = 1.12 [1.01-1.26], P = 0.027).

Atopic dermatitis is associated with active and passive cigarette smoking in adolescents.

OBJECTIVE: The relationship between passive smoking and atopic dermatitis has previously been reported, but few studies have simultaneously evaluated the association of atopic dermatitis with active and passive smoking. METHODS: The relationships between atopic dermatitis and active and passive smoking were evaluated in Korean adolescents. We used a large, representative, population-based survey (The Korea Youth Risk Behavior Web-based Survey) conducted in 2011 and 2012. Active smoking was classified into 3 groups (0 days, 1-19 days, and ≥ 20 days/month). Passive smoking was categorized into 3 groups (0 days, 1-4 days, and ≥ 5 days/week). Atopic dermatitis diagnosed by a medical doctor either during the past 1 month or during the participant's lifetime was surveyed. Age, sex, obesity status, region of residence, economic level, and parental educational level of the participants were adjusted as confounders. Adjusted odds ratios (AORs) and 95% confidence intervals (CI) were calculated using multiple logistic regression analysis with complex sampling. RESULTS: A total of 6.8% (10,020/135,682) of the participants reported atopic dermatitis during the last 12 months. Active smoking was significantly associated with atopic dermatitis (previous 12 months) (AOR [95% CI] of smoking ≥ 20 days/month = 1.18 [1.07-1.29]; 1-19 days/month = 1.11 [0.99-1.23], P = 0.002). Passive smoking was also related to atopic dermatitis (previous 12 months) (AOR [95% CI] of smoking ≥ 5 days/week = 1.12 [1.05-1.20]; 1-4 days/week = 1.08 [1.03-1.13], P < 0.001). CONCLUSION: Atopic dermatitis was significantly associated with active and passive smoking in Korean adolescents.

High stress, lack of sleep, low school performance, and suicide attempts are associated with high energy drink intake in adolescents.

OBJECTIVE: Although an association between energy drinks and suicide has been suggested, few prior studies have considered the role of emotional factors including stress, sleep, and school performance in adolescents. This study aimed to evaluate the association of energy drinks with suicide, independent of possible confounders including stress, sleep, and school performance. METHODS: In total, 121,106 adolescents with 13-18 years olds from the 2014 and 2015 Korea Youth Risk Behavior Web-based Survey were surveyed for age, sex, region of residence, economic level, paternal and maternal education level, sleep time, stress level, school performance, frequency of energy drink intake, and suicide attempts. Subjective stress levels were classified into severe, moderate, mild, a little, and no stress. Sleep time was divided into 6 groups: < 6 h; 6 ≤ h < 7; 7 ≤ h < 8; 8 ≤ h < 9; and ≥ 9 h. School performance was classified into 5 levels: A (highest), B (middle, high), C (middle), D (middle, low), and E (lowest). Frequency of energy drink consumption was divided into 3 groups: ≥ 3, 1-2, and 0 times a week. The associations of sleep time, stress level, and school performance with suicide attempts and the frequency of energy drink intake were analyzed using multiple and ordinal logistic regression analysis, respectively, with complex sampling. The relationship between frequency of energy drink intake and suicide attempts was analyzed using multiple logistic regression analysis with complex sampling. RESULTS: Higher stress levels, lack of sleep, and low school performance were significantly associated with suicide attempts (each P < 0.001). These variables of high stress level, abnormal sleep time, and low school performance were also proportionally related with higher energy drink intake (P < 0.001). Frequent energy drink intake was significantly associated with suicide attempts in multiple logistic regression analyses (AOR for frequency of energy intake ≥ 3 times a week = 3.03, 95% CI = 2.64-3.49, P < 0.001). CONCLUSION: Severe stress, inadequate sleep, and low school performance were related with more energy drink intake and suicide attempts in Korean adolescents. Frequent energy drink intake was positively related with suicide attempts, even after adjusting for stress, sleep time, and school performance.

High Incidence of Bell's Palsy After Mastoidectomy: A Longitudinal Follow-up Study.

OBJECTIVE: The objective of this study was to compare the prevalence of Bell's palsy in participants who underwent mastoidectomy (to treat chronic otitis media) and nonmastoidectomy participants (control). METHODS: Using the national cohort study from the Korean Health Insurance Review and Assessment Service, mastoidectomy patients (2,045) and control participants (8,180) were matched 1:4 for age, sex, income, and region of residence. The prevalence of Bell's palsy in both the groups was measured from 0 to 10 years postoperation. RESULTS: In a sample of 1,025,340 Korean individuals, 7,070 were diagnosed or treated with Bell's palsy between 2002 and 2013; the annual incidence of Bell's palsy was 0.057%. The overall prevalence of Bell's palsy was three times higher in the mastoidectomy group (1.27%) than control group (0.49%) (p < 0.001). The prevalence of Bell's palsy was different between the two groups in postoperative 0 year: 0.78% for the mastoidectomy group versus 0.01% for the control group (p < 0.001). CONCLUSION: Although we could not verify the laterality, the prevalence of Bell's palsy was increased in chronic otitis media patients treated with mastoidectomy patients compared with controls, especially within a year after surgery.

Physical Activity, Sedentary Habits, Sleep, and Obesity are Associated with Asthma, Allergic Rhinitis, and Atopic Dermatitis in Korean Adolescents.

PURPOSE: Since pathophysiologic evidence has been raised to suggest that obesity could facilitate an allergic reaction, obesity has been known as an independent risk factor for allergic disease such as asthma. However, the relationship between sedentary behavior and lifestyle which could lead to obesity, and those allergic diseases remains unclear. MATERIALS AND METHODS: We analyzed the relations between physical activity, including sitting time for study, sitting time for leisure and sleep time, and obesity, asthma, allergic rhinitis, and atopic dermatitis using the Korea Youth Risk Behavior Web-based Survey, which was conducted in 2013. Total 53769 adolescent participants (12 through 18 years old) were analyzed using simple and multiple logistic regression analyses with complex sampling. RESULTS: Longer sitting time for study and short sitting time for leisure were associated with allergic rhinitis. High physical activity and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis. Underweight was negatively associated with atopic dermatitis, whereas overweight was positively correlated with allergic rhinitis and atopic dermatitis. CONCLUSION: High physical activity, and short sleep time were associated with asthma, allergic rhinitis, and atopic dermatitis.

Severe hearing impairment and risk of depression: A national cohort study.

OBJECTIVE: Hearing impairment is suggested to be associated with depression in the elderly. The present study evaluated the risk of depression after hearing impairment in all age groups matched by age, sex, income, and region of residence. METHODS: The Korean Health Insurance Review and Assessment Service-National Patient Samples were collected for a period from 2002 to 2013. Hearing impairment was defined as a hearing threshold ≥ 60 dB in both ears or as ≥ 80 dB in one ear and ≥ 40 dB in one ear. Hearing-impaired participants performed a pure tone audiometry test 3 times and an auditory brainstem response threshold test once. The 6,136 hearing-impaired participants were matched 1:4 with 24,544 controls with no reported hearing impairment for age, sex, income, and region of residence. Depression was investigated based on the International Classification of Disease-10 codes F31 (bipolar affective disorder) through F39 (unspecified mood disorder) by a psychiatrist from 2002 through 2013. The crude (simple) and adjusted (age, sex, income, region of residence, dementia, hypertension, diabetes, and dyslipidemia) hazard ratio (HR) of hearing impairment on depression were analyzed using Cox-proportional hazard model. RESULTS: The rate of depression was significantly higher in the severe hearing-impaired group than in the control group (7.9% vs. 5.7%, P < 0.001). Severe hearing impairment increased the risk of depression (adjusted HR = 1.37, 95% confidence interval [CI] = 1.24-1.52, P < 0.001). In a subgroup analysis, young (0-29 years old), middle-aged (30-59 years old), and old (≥ 60 years old) severe hearing-impaired groups showed significantly increased risk of depression compared to controls with no reported hearing impairment. In accordance with income level, severe hearing impairment elevated depression in the low and high income groups, but not in the middle income group. CONCLUSION: Severe hearing impairment increased the risk of depression independently of age, sex, region, past medical histories, and income (in low and high income persons but not in middle income persons).