Sex-specific predictors of first major chronic disease or cancer events in Korean adults: a linked health screening and claims-based cohort study.

OBJECTIVES: This study aimed to identify sex- and age-specific predictors of the first onset of major chronic disease or cancer among Korean adults using linked National Health Insurance Service (NHIS)-Korean Association of Health Promotion (KAHP) data and a competing risk framework that accounts for death before disease onset. METHODS: A total of 102,870 adults who underwent KAHP health examinations in 2013 were followed through NHIS claims data until 2022. Nine major chronic diseases and cancers were identified using International Classification of Diseases, 10th Revision codes and clinical criteria. Sex-specific Fine-Gray subdistribution hazard models were fitted to estimate subdistribution hazard ratios. Model performance was evaluated using the time-dependent area under the receiver operating characteristic curve (AUROC) at 5 and 9.5 years. RESULTS: Age was the strongest predictor of first disease onset in both sexes. Cardiometabolic, inflammatory, liver-related, and lifestyle-related markers showed sex-specific associations. Ischemic heart disease was the most frequent first-occurring disease, accounting for 50.3% and 46.8% of first events in males and females, respectively. Time-dependent AUROC values ranged from 0.72 to 0.73, indicating moderate and stable discrimination. CONCLUSION: Using linked NHIS-KAHP data and a competing risk framework, this study identified sex-specific predictors of first major chronic disease or cancer onset. The models showed moderate and stable discrimination, supporting the value of sex-specific risk assessment for chronic disease prevention and healthy aging.