An analysis of physician utilization by elderly persons: systematic differences between self-report and archival information.

Elderly persons may over- or underreport their utilization of services, and systematic variance in this discrepancy may bias research findings. Therefore, this study analyzed the discrepancy between archival and self-report measures of physician utilization and examined the association of that discrepancy with health status and sociodemographic variables. Each older person underreported physician utilization by a net of .35 visits, but the total discrepancy was nearly two visits per person, or 65 percent of the number of self-reported visits. The multivariate findings indicate that underreports of utilization are smaller for those elderly persons with lower health status (as measured by disease history) and larger for those with higher levels of utilization. Those in poor health tend to overreport physician visits, and those with greater levels of utilization tend to have greater proportional reporting error. Self-reported measures of physician utilization should be considered in the context of the net error and the systematic nature of that error.