Recall bias did not affect perceived magnitude of change in health-related functional status.

Background And Objective: It was hypothesized that within an invasively treated group and within a group that improved in angina pectoris no difference in effect size would occur between prospective and retrospective measures. Furthermore, it was hypothesized that assessment of perceived change at post-test may be invalid because of recall bias and present-state bias.

Study Design And Setting: Effect sizes (as standardized response means) were used as indicators of magnitude of change.