Proxy use of the Canadian SF-36 in rating health status of the disabled elderly.

Professionals have often depended on proxies to assess health status of elderly individuals unable to provide this information. This study set out to estimate agreement between elderly subjects and their proxies on perceptions of health status, when patients were inpatients in a rehabilitation setting or outpatients in a day hospital, and to determine if there were overestimations or underestimations by proxies. Eighty-three consenting elderly patients living in Montreal, Canada, completed a generic health-status questionnaire, the SF-36, and named a significant other and a health care provider who knew them well. These individuals completed the same questionnaire on behalf of the patients. Agreement between patient and proxy was assessed pairwise (patient/health professional and patient/significant other) using intraclass correlation coefficients. The possibility of a biased rating by type of proxy was determined via paired t-tests. When concordance within respondent pairs was examined, results indicated only poor to moderate agreement regardless of setting and type of proxy for all scales. A trend toward underestimating by proxies was found. Proxy completion of health status questionnaires did not provide similar information, but these preliminary findings need replication.