Derivation of the analytical samples from the PRO-AGE study: a randomised controlled trial of Health Risk Appraisal for older persons based in general practice*. *For further information on trial design see reference 13. HRA-O = Health Risk Appraisal for Older persons.
Biddulph et al. BMC Geriatrics 2014 14:5 doi:10.1186/1471-2318-14-5