Effect of health protective factors on health deficit accumulation and mortality risk in older adults in the Beijing Longitudinal Study of Aging.

OBJECTIVES

To evaluate transitions in health status and risk of death in older adults in relation to baseline health deficits and protective factors.

DESIGN

Prospective cohort study with reassessments at 5, 8, and 15 years.

SETTING

Secondary analysis of data from the Beijing Longitudinal Study on Aging.

PARTICIPANTS

Urban and rural community-dwelling people aged 55 and older at baseline (n = 3,275), followed from 1992 to 2007, during which time 51% died.

MEASUREMENTS

Health status was quantified using the deficit accumulation-based frailty index (FI), constructed from 30 intrinsic health measures. A protection index was constructed using 14 extrinsic items (e.g., exercise, education). The probabilities of health changes, including death, were evaluated using a multistate transition model.

RESULTS

Women had more health deficits (mean baseline FI 0.13 ± 0.11) than did men (mean baseline FI 0.11 ± 0.10). Although health declined on average (mean FIs increased), improvement and stability were common. Baseline health significantly affected health transitions and survival over various follow-up durations (odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.17-1.37 for men; OR = 1.24, 95% CI = 1.16-1.33 for women for each increment of deficits). Each protective factor reduced the risk of health decline and the risk of death in men and women by 13% to 25%.

CONCLUSION

Deficit accumulation-based transition modeling demonstrates persisting effects of baseline health status on age-related health outcomes. Some mitigation by protective factors can be demonstrated, suggesting that improving physical and social conditions might be beneficial.