As the use of proxy respondents is sometimes necessary in research involving older or disabled people it is important to assess
the impact of this on research results. This study examined the concordance of proxy responses and index responses on questions
concerning functional abilities and continence. Index respondents were women aged 65 years and older who were interviewed
as part of a larger study of outcomes of fractured neck of femur, at 5 days post surgery. They were asked to nominate a proxy
respondent who was interviewed using the same questions within a few days. Responses of proxy and index respondents were compared
using percentage agreement and Kappa statistics. On questions regarding functional ability, proxy responses were found to
be more reliable for personal care activities than for instrumental activities of daily living. This may be a result of questions
concerning instrumental activities being somewhat more ambiguous and open to individual interpretation. Item non-response
was low for all questions thus resulting in little missing data for proxy respondents. There was a tendency for more distant
relationship and contact to produce better agreement, which is contrary to previous findings. Proxy responses were biased
in the direction of an overestimation of functional incapacity and so researchers should be cautious in combining data from
proxy and index respondents. Concordance was good for questions concerning urinary and faecal incontinence although non-response
was higher than for functional ability questions. Concordance was not as great for more detailed questions concerning the
timing and frequency of incontinence as these used graded response options, rather than simple yes/no responses.
Elderly - Fractured neck of femur - Proxy respondents - Reliability
This revised version was published online in June 2006 with corrections to the Cover Date.