Survey into health problems of elderly people: a comparison of self-reportwith proxy information

Background This study was conducted as part of the Medical Research Council Cognitive Function and Ageing Study. Objective To compare information given by elderly people on their past and current health and family history of illness with similar information obtai ned from a relative, friend or carer. Design Screening and assessment stages of a prevalence study. Setting Three urban and two rural areas of England and Wales. Participants A subsample weighted by age and cognitive status of random pop ulation samples of people greater than or equal to 65 years, living in thei r own home or in a residential or nursing home, interviewed between 1991 an d 1994. A relative, friend or carer identified by each elderly person to pr ovide proxy information. Interview Computerized schedules including items on demographic details, co gnitive function, lifetime illnesses, current health problems and family hi story of illness. Results The rate of proxy 'don't know' responses and the agreement between the elderly person and their proxy were calculated for each item, both for the overall sample and for subgroups based on characteristics of the respon dent and of the proxy and on the relationship between them. Higher 'don't k now' rates were found to be particularly associated with more distant relat ionships, questions on family history, a shorter length of time known and a lack of co-residence. Agreement was strongly related to the nature of the question and less to co-residence, with other factors such as relationship having much smaller effects. Conclusions Proxy information on past and current health problems can be al most complete and in good agreement with self-report, particularly where th e proxy lives with the respondent. On family history of illness, history of head injury or boxing and current sleep problems, proxy information is lik ely to be less complete and show poor agreement. A proxy who is not a close relative is likely to give less complete information but agreement will no t be substantially lower.