Background Increased longevity may increase the burden of disability in the near future. However, much depends on current and future trends in cardiovascular disease, dementia and their shared risk factors.

We set out to forecast future trends in disability and life expectancies in England and Wales to 2025, using a model which combines the population dynamics and ongoing trends of these two diseases.

Methods As part of the IMPACT-Better Ageing Model study, a probabilistic Markov model was developed and validated to track health transitions of the England and Wales population through nine states characterised by presence or absence of cardiovascular disease, dementia and disability from 2012 to 2025.

Disease occurrence and age/sex/year specific transition probabilities were derived from the English Longitudinal Study of Ageing and Health Survey for England. We estimated future disability prevalence, life expectancy, disability-free life expectancy and disabled life expectancy.

We assumed cardiovascular disease incidence and mortality continue their current trends and dementia incidence continues to decline by 2% per annum. Monte Carlo simulation was used to estimate 95% uncertainty intervals (UI) for all the model outputs.

Results By 2025, approximately 157,000 (95% UI 142,000–176,000) additional people will live with disability, a 12.4% (11.5%–13.7%) increase from the 2015 baseline. Prevalence of disability will decrease among women (from 12.7% to 11.3%), but not men. Larger decreases in prevalence will be seen in women over 90 years of age (from 37.5% to 31.4%).

In 2015, the Office of National Statistics estimated life expectancy at age 65 in England and Wales to be 18.8 years in men and 21.1 years in women. Between 2015 and 2025, we predict life expectancy at age 65 will increase to 22.0 (21.5–22.5) years in men and 24.1 years (23.0–25.5) in women. Disability-free life expectancy will increase in men by 2.0 (1.7–2.4) years and in women by 1.8 (1.0–2.6) years. However, disabled life expectancy will only increase marginally.

Overall, the proportion of life expectancy lived without disabilities would remain constant at around 85.6%.

Discussion Because of population ageing, the number of people in England and Wales with disability will increase by approximately 12% by 2025. However, prevalence of age-related disability is predicted to decrease over the coming decade. If the continuing downward trend in dementia and cardiovascular disease incidence is observed, the anticipated increase in life expectancy will occur without additional years lived with disability.