Background Rates of hospital admission are increasing, particularly among older people. Poor health behaviours cluster but their combined impact on risk of hospital admission among older people in the UK is unknown.

Methods 2997 community-dwelling men and women (aged 59–73) participated in the Hertfordshire Cohort Study (HCS). We scored (from 0 to 4) number of poor health behaviours engaged in at baseline (1998–2004) out of: current smoking, high weekly alcohol, low customary physical activity and poor diet. We linked HCS with Hospital Episode Statistics and mortality data to 31/03/2010 and analysed associations between the score and risk of different types of hospital admission: any; elective; emergency; long stay (>7 days); 30-day readmission (any, or emergency).

Results 32%, 40%, 20% and 7% of men engaged in 0, 1, 2 and 3/4 poor health behaviours; corresponding percentages for women 51%, 38%, 9%, 2%. 75% of men (69% women) experienced at least one hospital admission. Among men and women, increased number of poor health behaviours was strongly associated (p<0.01) with greater risk of long stay and emergency admissions, and 30-day emergency readmissions. Hazard ratios (HRs) for emergency admission for 3/4 poor health behaviours in comparison with none were: men, 1.37 (95% CI 1.11 to 1.69); women, 1.84 (95% CI 1.22 to 2.77). Associations were unaltered by adjustment for age, body mass index and comorbidity.

Conclusions Clustered poor health behaviours are associated with increased risk of hospital admission among older people in the UK. Lifecourse interventions to reduce number of poor health behaviours could have substantial beneficial impact on health and use of healthcare in later life.