Background: This study aimed to develop an instrument for assessing physical functioning among adults aged 50 years or older living in the community. Methods: Based on a review of various national health surveys and cohort studies, a 144-item bank was constructed for assessing physical functioning. Focus group interviews were conducted among adults aged 50 years or older to investigate their level of understanding of 60 selected items, followed by a pretest of the items on a nationally representative sample (n=508). The final 25-item questionnaire was tested on an independent sample (n=259) for validity and reliability based on classical test and item response theories. Predictive validity at the 6-month follow-up was tested in a separate sample (n=263). Results: The newly developed Life Functioning (LF) scale assessed the dimensions of functional limitations, disabilities, and social activities. The scale satisfied a one-dimensionality assumption with good item fit and demonstrated criterion validity, construct validity, high internal consistency (Cronbach’s alpha=0.93), and test-retest reliability (intra-class correlation coefficient=0.84; 95% confidence interval, 0.76–0.89). The LF scale comprised 25 items with a total score ranging from 0 to 100. Higher scores indicated higher levels of functioning. The LF score was significantly associated with the Physical Functioning score at 6 months. Conclusion The LF scale was developed to assess the physical functioning of people in their late midlife or older. Future studies should test the instrument on a national sample and evaluate its application in diverse population subgroups.

Background: This study aimed to develop an instrument for assessing physical functioning among adults aged 50 years or older living in the community. Methods: Based on a review of various national health surveys and cohort studies, a 144-item bank was constructed for assessing physical functioning. Focus group interviews were conducted among adults aged 50 years or older to investigate their level of understanding of 60 selected items, followed by a pretest of the items on a nationally representative sample (n=508). The final 25-item questionnaire was tested on an independent sample (n=259) for validity and reliability based on classical test and item response theories. Predictive validity at the 6-month follow-up was tested in a separate sample (n=263). Results: The newly developed Life Functioning (LF) scale assessed the dimensions of functional limitations, disabilities, and social activities. The scale satisfied a one-dimensionality assumption with good item fit and demonstrated criterion validity, construct validity, high internal consistency (Cronbach’s alpha=0.93), and test-retest reliability (intra-class correlation coefficient=0.84; 95% confidence interval, 0.76–0.89). The LF scale comprised 25 items with a total score ranging from 0 to 100. Higher scores indicated higher levels of functioning. The LF score was significantly associated with the Physical Functioning score at 6 months. Conclusion The LF scale was developed to assess the physical functioning of people in their late midlife or older. Future studies should test the instrument on a national sample and evaluate its application in diverse population subgroups.

Background: This study aimed to develop an instrument for assessing physical functioning among adults aged 50 years or older living in the community. Methods: Based on a review of various national health surveys and cohort studies, a 144-item bank was constructed for assessing physical functioning. Focus group interviews were conducted among adults aged 50 years or older to investigate their level of understanding of 60 selected items, followed by a pretest of the items on a nationally representative sample (n=508). The final 25-item questionnaire was tested on an independent sample (n=259) for validity and reliability based on classical test and item response theories. Predictive validity at the 6-month follow-up was tested in a separate sample (n=263). Results: The newly developed Life Functioning (LF) scale assessed the dimensions of functional limitations, disabilities, and social activities. The scale satisfied a one-dimensionality assumption with good item fit and demonstrated criterion validity, construct validity, high internal consistency (Cronbach’s alpha=0.93), and test-retest reliability (intra-class correlation coefficient=0.84; 95% confidence interval, 0.76–0.89). The LF scale comprised 25 items with a total score ranging from 0 to 100. Higher scores indicated higher levels of functioning. The LF score was significantly associated with the Physical Functioning score at 6 months. Conclusion The LF scale was developed to assess the physical functioning of people in their late midlife or older. Future studies should test the instrument on a national sample and evaluate its application in diverse population subgroups.

Objective: Even though studies using machine learning on sleep-wake states have been performed, studies in various conditions are still necessary. This study aimed to examine the performance of the prediction model of locomotor activities on sleep-wake states using machine learning algorithms. Methods: The processed data using moving average of locomotor activities were used as predicting features. The sleep-wake states were used as true labels. The prediction models were established by machine learning classifiers such as support vector machine with radial basis function (SVM-RBF), linear discriminant analysis (LDA), naïve Bayes, and random forest (RF). The prediction model was evaluated by a six-fold cross validation. Results: The SVM-RBF and RF showed acceptable performance within a window of moving average from 480 to 1,200 seconds. The highest accuracy (0.869) was shown by the RF at the interval of 480 seconds. Meanwhile, the highest area under the curve (0.939) was shown by LDA at the interval of 870 seconds. Conclusion This study suggested that the prediction model on sleep-wake state using machine learning could show an improvement of the model performance when using moving average with raw data. The prediction model using locomotor activity can be useful in research on sleep-wake state.

Objectives: Schizophrenia (SPR) is the most devastating mental illness that causes severe deterioration in social and occupational functioning, but, the aetiology remains unknown. The aim was to identify patterns of association and segregation for genetic variants and to identify the genes and signalling pathways that determine the risk of developing SPR, through a family-based Genome-wide association study. Methods: We have recruited 27 probands(with SPR) with their parents and siblings whenever possible. DNA was extracted from blood sampling of 58 individuals in 27 families and analysed in an Illumina core exome single nucleotide polymorphism (SNP) array. A family-based association test was used to derive SNP association values across all chromosomes. Results: Although none of the final 800,000 SNPs reached the genome-wide significant threshold of 5×10-8 , the most significant 3 SNPs were within the 10-5 -10-7 . Conclusions This confirms that SPR is not monogenic but results as a consequence of interactions between multiple host genes and possibly also environmental factors. The present approach provides novel insights into the mechanisms underlying SPR and raises the possibility of identifying individuals at risk of acquiring this condition. In this study, several possible susceptibility genes have been identified that are linked to a range of different pathways, which could reflect the mind-body interaction that is included in the psychiatric genomics consortium.

OBJECTIVES: This study aimed to investigate changes in health behaviors, including cigarette smoking, alcohol drinking, physical activity, dietary behaviors, and obesity, before and during the coronavirus disease 2019 (COVID-19) pandemic using the Korea Youth Risk Behavior Survey (KYRBS) database. METHODS: KYRBS data from 2015 to 2021 were used in this study. Differences in health behaviors between before (pre-pandemic period: 2018-2019) and during (pandemic period: 2020-2021) the pandemic were examined. Differences were compared using linear regression and the chi-square test considering the complex survey design after adjusting for grade level. RESULTS: The prevalence of current cigarette smoking and current alcohol drinking significantly decreased in both male and female students during the pandemic compared to the pre-pandemic period. However, the prevalence of obesity significantly increased in both male and female students during the same period. When examining physical activity and dietary behaviors closely related to obesity, fast food consumption increased and fruit consumption decreased during the pandemic in both male and female students, whereas no significant changes in physical activity were observed in either male or female students. CONCLUSIONS The deterioration of adolescent dietary behaviors and an increase in the prevalence of obesity can increase the future disease burden, and concerted efforts at the individual and national levels are needed to reduce obesity and promote healthy dietary behaviors.

OBJECTIVES: This study was to examine the changes in dietary habits and food and nutrient intakes between before (2019) and during (2020) the coronavirus disease 2019 (COVID-19) pandemic from the Korea National Health and Nutrition Examination Survey (KNHANES). METHODS: A total of 54,995 participants aged ≥19 years who participated in the 2011-2020 KNHANES were included. The 10-year trend (2011-2020) and differences between 2019 and 2020 for dietary habits and food and nutrient intakes were estimated using SAS. RESULTS: In the past 10 years (2011-2020), the dietary habits (increase in skipping meals and eating out), food intake (increase in meats and decrease in fruits and vegetables), and nutrient intake (increase in fat and decrease in sodium) in adults have changed. When comparing between 2019 and 2020, there were 4.6%p decrease in the eating out more than once a day. On the other hand, there were no significant differences in the intakes of food, energy and most of nutrients between 2019 and 2020, except for the proportion of energy intake from fat (1.0%p increase) and carbohydrate (1.0%p decrease). CONCLUSIONS Although a change in dietary habits from before to during the COVID-19 pandemic was observed, food and nutrient intakes have not deteriorated markedly and appear similar to the trends in the past 10 years. Throughout the COVID-19 pandemic, it is necessary to monitor the effects of changes in dietary habits on health as well as food and nutrient intakes.

OBJECTIVES: We aimed to study the effects of the coronavirus disease 2019 (COVID-19) pandemic on adolescents’ mental health in Korea. METHODS: We used data from the Korea Youth Risk Behavior Survey 2018-2021 with 227,139 students aged 12-18 years. We estimated the differences in depressive symptoms, suicidal ideation, and stress perception before (2018-2019) and during (2020-2021) the pandemic, as well as before (2019), the first year (2020) of, and the second year (2021) of the pandemic. We also examined whether COVID-19 is statistically associated with mental health. RESULTS: In both male and female adolescents, the prevalence of depressive symptoms, suicidal ideation, and stress perception was higher in the “not living with family,” “low household economic status,” and “self-rated unhealthy status” subgroups. The prevalence of depressive symptoms and stress perception was higher in middle school students. Adolescents were less likely to experience depressive symptoms (adjusted odds ratio [aOR], 0.86; 95% confidence interval [CI], 0.83 to 0.89), suicidal ideation (aOR, 0.80; 95% CI, 0.76 to 0.83), and stress perception (aOR, 0.76; 95% CI, 0.74 to 0.79) in 2020 than in 2019. However, there were more depressive symptoms (aOR, 1.06; 95% CI, 1.02 to 1.09), suicidal ideation (aOR, 1.15; 95% CI, 1.10 to 1.21), and stress perception (aOR, 1.19; 95% CI, 1.16 to 1.23) in 2021 than in 2020. CONCLUSIONS The COVID-19 pandemic had positive impacts on mental health of adolescents in its early stages but has had negative impacts as the pandemic continues. Attention should be paid to adolescents who are particularly vulnerable to the mental health effects of the pandemic.

OBJECTIVES: This study aimed to analyze the changes in chronic disease management indicators, including hypertension, diabetes mellitus, and hypercholesteremia, from 2010-2020 and before (2019) and during (2020) the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This study included 58,504 individuals aged ≥30 years who participated in the Korea National Health and Nutrition Examination Survey 2010-2020. Trends in the prevalence, awareness, treatment, and control of chronic diseases and the difference in those between before and during the COVID-19 pandemic were analyzed using the SAS program PROC SURVEYREG. RESULTS: From 2010-2020, the awareness, treatment, and control in adults aged ≥30 years for hypertension and hypercholesterolemia continuously improved, whereas no significant change in the management indicators of diabetes mellitus was observed. The prevalence of hypertension, diabetes mellitus, and hypercholesterolemia in men increased from before to during the COVID- 19 pandemic. However, there was no significant change in the management indicators of hypertension and diabetes mellitus in men and women, and the awareness, treatment, and control rates for hypercholesterolemia increased by 5.5%p, 6.9%p, and 4.1%p respectively. CONCLUSIONS In 2020, the first year of the COVID-19 pandemic, the prevalence of hypertension, diabetes mellitus, and hypercholesterolemia increased, but the management indicators of the chronic diseases did not significantly deteriorate. Considering the ongoing COVID-19 pandemic, it is necessary to monitor changes in chronic disease management indicators and to develop efficient and accessible chronic disease prevention and management programs.