Self-rated health trajectory and frailty among community-dwelling older adults: evidence from the Taiwan Longitudinal Study on Aging (TLSA)

Abstract

Objectives: Self-rated health (SRH) is an assessment and predictor of health based on an individual's general condition; however, evidence of the value of SRH for predicting frailty remains scarce for older Asian adults. This study aimed to evaluate the relationship between SRH score trajectory and frailty among older individuals in Taiwan.

Design: An 8-year retrospective cohort study.

Setting: Data were retrieved from the Taiwan Longitudinal Study on Aging from 1999 to 2007.

Participants: Respondents aged 53-69 years old who were not frail or disabled in 1999 (n=1956).

Primary and secondary outcome measures: Frailty was defined using the Fried criteria. The group-based trajectory modelling technique was used to estimate SRH trajectories. Logistic regression analysis was used to examine the associations between changes in SRH and frailty.

Results: Four SRH trajectory classes were identified across the 8-year follow-up: 232 participants (11.9%) were classified into the constantly poor SRH group, 1123 (57.4%) into the constantly fair SRH group, 335 (17.1%) into the constantly good SRH group and 266 (13.6%) into the good-to-fair SRH group. After adjusting for gender, age, level of education, income, social participation, health behaviours and major comorbidities, it was found that age, poor income satisfaction, without job and constantly poor SRH were associated with increased risk of frailty, while constantly good SRH (OR 0.04, 95% CI (0.01 to 0.32)) and good-to-fair SRH (OR 0.19, 95% CI (0.06 to 0.63)) were associated with reduced risks of frailty.

Conclusions: Constantly poor SRH was associated with an increased risk of frailty in older age. SRH in older adults should be recognised as a predictive tool for future frailty. Diet and exercise interventions may help to prevent frailty among high-risk older individuals with constantly low SRH.

Keywords: epidemiology; geriatric medicine; public health.

Figure 1

Flowchart of the study design. Flowchart showing the patient inclusion and exclusion processes, and the process of group-based trajectory analysis. SRH, self-rated health; TLSA, Taiwan Longitudinal Study on Aging; BIC, Bayesian Information Criterion.

Figure 2

Trajectories of SRH score between 1999 and 2007. After group-based trajectory analysis, there were 232 participants (11.9%, group 1) in the constant poor SRH group, 1123 participants (57.4%, group 2) in the constant fair SRH group, 335 participants (17.1%, group 3) in the constant good SRH group and 266 participants (13.6%, group 4) in the good-to-fair SRH group. SRH, self-rated health.