Background: Researchers conducting cost-outcome studies must account for all materially relevant care that subjects receive from their care providers. However, access to provider records is often limited. This article describes and tests the Utilization and Cost Inventory (UAC-I), a structured patient interview designed to measure costs of care when access to provider records is limited.
Methods: UAC-I was tested on 212 consenting adult veterans with mood disorder attending a VA medical center. Counts (inpatient days and outpatient encounters) and costs (dollars) computed from survey responses were compared with estimates from medical records and an alternative structured questionnaire.
Results: The agreement between inpatient costs computed from provider records and from UAC-I responses, assessed using the intraclass correlation coefficient (ICC), was 0.66, 95% confidence interval (CI), 0.30-0.84; the bias was -3.7%, 95% CI, -48 to 41. The ICC for the service data (inpatient days) was 0.97, 95% CI, 0.95-0.99; the bias was <1%, 95% CI, -14 to 15. The ICC for outpatient costs computed from provider records and from UAC-I responses was 0.53 95% CI, 0.38-0.65; the bias was <1%, 95% CI, -27 to 27. The ICC for outpatient encounters was 0.74, 95% CI, 0.65-0.80; the bias was <1%, 95% CI, -16 to 18.
Conclusions: These results indicate that it may be feasible for cost-outcome studies to compare patient groups for inpatient and outpatient costs computed from patient self-reports.