How reliable are stroke patients' reports of their numbers of general practice consultations over 12 months?

BACKGROUND: Data on primary health care use are frequently used in economic evaluations. However, it is unclear how patient self-reports of their number of consultations with their general practitioner (GP) relate to actual consultations in the electronic records. These data are crucial if self-reports are used to conduct economic evaluations.
OBJECTIVES: To report the accuracy of stroke patients' self-reports of their number of primary care consultations over a 12-month period by comparison with practice-held electronic records. We also recorded the number of contacts required to collect service use data from the practices.
METHODS: We contacted 65 practices requesting electronic consultation records over 12 months for 115 stroke patients who took part in a trial of home blood pressure monitoring. Consultation rates from the electronic records were compared with patients' self-reported number of consultations from a questionnaire covering the same period.
RESULTS: Fifty-one practices (78%) responded. Patients' questionnaires (n = 83) reported a mean of 5.7 consultations with their GP per year compared with 7.2 in the electronic records (difference 1.6, 95% confidence interval 0.5-2.7, P < 0.01). The mean time taken to obtain records from practices was 6 weeks.
CONCLUSIONS: Patients modestly under-reported the number of consultations they had with a GP. Obtaining patient records from practices required more effort than obtaining information from patient questionnaires at the same time as assessing main trial outcomes. If patient self-reports of health care usage are used in economic evaluations in primary care, researchers should consider validating a sample against electronic records.