Health-related quality of life trajectories and loss of independence among community-dwelling older adults

Health-related quality of life (HRQOL) is a key determinant of loss of independence (LOI) among older adults. However, the relationship between late-life HRQOL trajectory patterns and the risk of LOI remains unclear. This study utilized 5-year longitudinal data from the Sukagawa Study, and group-based trajectory modeling. HRQOL trajectories were analyzed using the mental component scale (MCS) and physical component scale (PCS) from the SF-8. Hazard ratios (HRs) and 95% confidence intervals (CIs) for LOI or death were calculated using Cox proportional hazards regression. Among 4043 participants (median age 78.8 years, interquartile range [IQR] 75.8-82.5; 56% women), HRQOL change score trajectories were categorized as decline, stable, and increase for MCS (11.7%, 81.0%, 7.2%) and PCS (10.9%, 81.4%, 7.6%). Over a mean follow-up of 66.4 months (IQR 48.0-73.0), LOI or death incidence was 42.5 per 1000 person-years (95% CI 39.8-45.2). Compared to the stable group, MCS decline was associated with higher LOI or death risk (HR 1.51, 95% CI 1.04-2.18), and an increase was associated with lower risk (HR 0.26, 95% CI 0.11-0.57). PCS decline was linked to higher LOI risk (HR 1.66, 95% CI 1.17-2.37), while an increase showed no significant association (HR 1.07, 95% CI 0.61-1.89). Longitudinal HRQOL trajectory is closely related to LOI risk among community-dwelling older adults. A declining trajectory in physical and mental components is strongly associated with higher LOI risk, while an increasing trajectory in the mental component is possibly associated with lower risk.