AUTHOR=Yang Jeong Min , Kim Jang Mook , Jang Tae Su , Hwang Jieun 
  
TITLE=Joint trajectories of health behaviors and their associations with healthcare utilization and expenditure
  
JOURNAL=International Journal of Public Health
  
VOLUME=Volume 71 - 2026
  
YEAR=2026
  
URL=https://www.ssph-journal.org/journals/international-journal-of-public-health/articles/10.3389/ijph.2026.1609686
  
DOI=10.3389/ijph.2026.1609686
  
ISSN=1661-8564
  
ABSTRACT=ObjectivesThis study identified sex-specific trajectories of key health behaviors among middle-aged and older adults and examined their longitudinal associations with healthcare utilization and expenditure.MethodsWe analyzed 167,343 Korean adults aged 40–79 years from 2002 to 2019 using the National Health Insurance Service Health Screening Cohort. Group-based multi-trajectory modeling identified joint trajectories of smoking, alcohol consumption, physical activity, and BMI. Associations with healthcare outcomes were assessed using generalized estimating equations stratified by sex and age group.ResultsSix distinct health behavior trajectories were identified in both sexes. Among men, the higher moderate-risk trajectory showed fewer outpatient visits but longer hospital stays. Among women, the higher severe-risk trajectory was associated with increased expenditures and higher healthcare utilization. Age-stratified analyses revealed stronger associations for severe-risk trajectories in men aged <65 years and lower severe-risk trajectories in those aged ≥65 years.ConclusionSex- and age-specific behavioral trajectories were differentially associated with healthcare utilization and expenditure, underscoring the importance of multidimensional behavioral patterns in developing preventive strategies to reduce healthcare burdens.