Temporal Trends in the Prevalence of Frailty in England From 2002 to 2022, With Forecasts to 2040: Longitudinal Secondary Analysis of a National Cohort Study
Background: The increasing life expectancy provides an opportunity for healthy longevity, but frailty is a potential challenge. Existing studies of frailty prevalence in England are largely cross-sectional, use heterogeneous frailty definitions, and rarely break down population-level drivers or project future burden, limiting their use for health and social care planning. Objective: This study aimed to explore temporal trends of frailty prevalence and project scenario-based future prevalence up to 2040 for the community-dwelling population aged 50 years and older in England. Methods: Prevalence of frailty (measured using a frailty index) in the overall sample and subgroups of age, sex, educational level, and marital status from 2002 to 2022 was estimated among the community-dwelling population aged 50 years and older using 10 waves of nationally representative data from the English Longitudinal Study of Ageing (ELSA; n=6226 to 11,218 across waves). The number of individuals with frailty was also derived in each year. Joinpoint regression models were used to explore temporal trends of frailty prevalence. A linear probability regression model was performed using pooled data from 10 waves of the ELSA to explore driving factors and project future prevalence. Decomposition analysis was used to estimate the contribution of individual factors to the change in prevalence. Results: A statistically nonsignificant (=.61) increase of 2.3 percentage points from 15.5% (1738/11,218) in 2002 to 17.8% (1108/6226) in 2022 was observed, with the number of individuals with frailty growing from 2,560,122 to 3,791,038 among community-dwelling adults aged 50 years and older in England. Those with advanced age, who were female, had a lower educational level, and/or were single had a consistently higher prevalence of frailty. Opposing contributions netted to this overall change: improvements in sociodemographic conditions and educational attainment and healthier lifestyle behaviors offset 222.5%, 94.9%, and 51.6% of the observed increase, respectively. Under scenario-based projections, prevalence was estimated at 20.5% (95% CI 19.2%-21.9%) in 2040, corresponding to 5,213,689 people with frailty. Conclusions: Despite a modest increase in prevalence among the community-dwelling population aged 50 years and older, the substantial growth in the absolute number of individuals with frailty indicates a likely rise in future care demands. The study contributes a 20-year trend, decomposition, and forecast framework for community-dwelling older adults. Findings support prioritizing broader sociodemographic development alongside educational attainment and healthy lifestyles, with potential policy approaches including income and social protection, housing improvements, access to health care, and prevention. Key limitations include self-reported measures, exclusion of care home residents, and potential influence of unmeasured effects.