Associations of behavioural risk factors and health status with changes in physical capability over 10\hspace0.25emyears of follow-up: the MRC National Survey of Health and Development.

Objectives (1) To describe changes in objective measures of physical capability between ages 53 and 60–64 years; (2) to investigate the associations of behavioural risk factors (obesity, physical inactivity, smoking) and number of health conditions (range 0–4: hand osteoarthritis (OA); knee OA; severe respiratory symptoms; other disabling or life-threatening conditions (ie, cancer, cardiovascular disease, diabetes)) at age 53 years with these changes. Design Nationally representative prospective birth cohort study. Setting England, Scotland and Wales. Participants Up to 2093 men and women from the Medical Research Council National Survey of Health and Development, who have been followed-up since birth in 1946, and underwent physical capability assessments performed by nurses following standard protocols in 1999 and 2006–2010. Main outcome measures Grip strength and chair rise speed were assessed at ages 53 and 60–64 years. Four categories of change in grip strength and chair rise speed were identified: decline, stable high, stable low, a reference group who maintained physical capability within a ‘normal’ range. Results Less healthy behavioural risk scores and an increase in the number of health conditions experienced were associated in a stepwise fashion with increased risk of decline in physical capability, and also of having low levels at baseline and remaining low. For example, the sex and mutually adjusted relative-risk ratios (95% CI) of being in the stable low versus reference category of chair rise speed were 1.58 (1.35–1.86) and 1.97 (1.57–2.47) per 1 unit change in behavioural risk score and health indicator count, respectively. Conclusions These findings provide evidence of the associations of a range of modifiable factors with age-related changes in physical capability. They suggest the need to target multiple risk factors at least as early as mid-life when aiming to promote maintenance and prevent decline in physical capability in later lif