The Short-Form 36 and older people: some problems encountered when using postal administration

To explore some of the problems encountered in the postal administration of the Short-Form 36 (SF-36). Questions that seem to present particular difficulties for the group are identified. In addition some of the written comments from the questionnaires and people's responses to questions on how difficult they found the SF-36 are discussed.

The study group were asked to complete a health questionnaire containing the SF-36 on three separate occasions (at zero, three, and six months). The first and final questionnaires were interviewer administered during a face to face interview. A shorter questionnaire containing only the SF-36 and another health status measure was sent by post to each patient in the interim.

People aged 65 years or above who were new referrals to community based occupational therapy or physiotherapy services in three areas in north west England.

Response and completion rates for the postal questionnaire were lower than expected, even though all the patients had already had a face to face interview and had therefore completed the SF-36 once. Only 34 of 56 respondents (60.7%) completed all the items on the SF-36.

All those planning to use the SF-36 (and similar measures) with older populations should be sensitive to the problems of postal administration. Non-return of questionnaires, high levels of missing data on those that are received, and ambiguities in response may mean that other measures, or perhaps alternative research methods, are more appropriate.