Diaries or questionnaires for collecting self-reported healthcare utilisation and patient cost data? CHERE Project Report No 20

The literature comparing diaries and questionnaires was reviewed in order to identify the most appropriate method of collecting patient self-reported data, on health service utilisation and out-ofpocket costs, for a longitudinal study. Nine published studies met the review inclusion criteria; four compared the diary method with a self-completed questionnaire and five with an interviewer administered questionnaire. None of the eligible studies measured patient costs, and only two measured some aspects of health service utilisation. Most of the studies reported higher response rates for questionnaires than for diaries, and there was some evidence of selection bias. There was a tendency to report more symptoms, symptom intensity or health care utilisation by questionnaires compared to diaries, and compared to physician reports (included in only two studies). The review provides some information about the two approaches for collecting self-reported data, but does not provide sufficient evidence to favour either approach.