Oral health-related quality of life and active aging in Korean older adults: A longitudinal panel study with marginal structural model sensitivity analyses

BACKGROUND: Oral health is an essential but underappreciated component of healthy and active aging. However, evidence distinguishing contemporaneous associations from prospective relationships with multidimensional active aging remains limited. METHODS: We analyzed three waves (2018-2022) of the Korean Longitudinal Study of Aging. Descriptive analyses included 7213 individuals contributing 19,482 person-wave observations; lagged prospective analyses included 6438 individuals contributing 12,173 two-year transitions. Oral health-related quality of life was measured using the GOHAI, and active aging using a composite AAI. We estimated contemporaneous associations using GEE and prospective associations using lagged models, stabilized IPTW, modified Poisson models, continuous GOHAI sensitivity analyses, domain-specific analyses, and stratified analyses. RESULTS: Higher GOHAI was strongly associated with lower odds of low active aging in conventional analyses. In crude lagged GEE, high GOHAI at time t was associated with lower odds of low AAI at time t + 1 (OR=0.67, 95% CI: 0.62-0.72). This association attenuated after adjustment for prior active aging and time-varying covariates (OR=0.90, 95% CI: 0.81-1.00) and was not significant in the IPTW-weighted MSM (OR=1.07, 95% CI: 0.99-1.15). Modified Poisson models were similar (RR=1.04, 95% CI: 0.99-1.08). A modest protective association remained among participants with low active aging at time t. CONCLUSION: GOHAI was strongly associated with active aging cross-sectionally, but its prospective population-average association attenuated after adjustment for prior active aging and time-varying confounding.