OBJECTIVES: To derive two household context factors - living alone and living in a two-person household with a person who is frail - from routine administrative health data and to assess their association with emergency hospital use in people aged 65 or over. DESIGN: Retrospective cohort study using national pseudonymised hospital data and pseudonymised address data derived from a minimised version of the Master Patient Index, a central database of all patient registrations in England. SETTING: England-wide. PARTICIPANTS: 4 876 285 people aged 65 years or older registered at GP practices in England on 16 December 2018 who were living alone or in a household of up to six people, and with at least one hospital admission in the last 3 years. OUTCOMES: Rates of accident and emergency (A&E) attendance and inpatient emergency admissions over a 1-year follow-up period. RESULTS: Older people living alone had higher rates of A&E attendances (adjusted rate ratio 1.09, 95% CI 1.09 to 1.10) and emergency admissions (1.14, 95% CI 1.14 to 1.15) than older people living in households of 2-6 people. Older people living with someone with frailty in a two-person household had higher rates of A&E attendance (adjusted rate ratio 1.09, 95% CI 1.08 to 1.10) and emergency admissions (1.10, 95% CI 1.09 to 1.11) than other older people living in a two-person household. CONCLUSIONS: We show that household context factors can be derived from linked routine administrative health data and that these are strongly associated with higher emergency hospital use in older people. Using household context factors can improve analyses, as well as support in the understanding of local population needs and in population health management.