The primary outcome was all-cause five-year mortality. Participants were followed for five years after their baseline date or until death within five years. Deaths during follow-up were ascertained from the VA vital status file which uses multiple sources including: (i) the Patient Treatment File, which records hospital deaths in the VA healthcare system; (ii) the Beneficiary Identification Records Locating System, which tracks VA death benefits; (iii) the Medicare Vital Status File, containing vital statistics records including death information on all Medicare beneficiaries; and (iv) the Social Security Death Master File, containing information on deceased persons that is typically collected in connection with filing of benefits by family members.
