Health care utilization: measurement using primary care records and patient recall both showed bias

To assess reasons for discrepancies between primary care consultation measured from patient self-report and that based on medical records.

Retrospective comparison of recalled consultation in previous 12 months among 2,414 subjects aged 50+ who reported knee pain in a population survey vs. primary care medical records. Record review included (1) all knee morbidity codes and (2) knee problems mentioned in consultation text. It was then extended to: (3) more than 12 months before survey, and (4) consultations for leg or widespread problems (e.g., generalized osteoarthritis).

In those who reported knee pain, recalled consultation prevalence for knee problems "in past year" was 33% compared with 15% based on medical records. Forty percent of those with a recalled consultation had a recorded knee problem in the same time period (kappa = 0.43). Expanding record search to include leg and widespread problems, and knee problems up to 40 months prior to survey, increased "verified" self-reported consulters to 80%.

Disparity in estimates of consultation prevalence arose from inaccuracy of: (1) recall in survey responders and (2) recording by general practitioners of specific problems and repeat consultations. Perceived importance of problem in a multiproblem contact and whether it leads to an outcome (e.g., prescription) may influence recording. Implications exist for service provision projections and research.