Comparing prospective and retrospective measures of treatment outcomes.

This study examines the correspondence between retrospective and prospective assessments of treatment outcomes among female patients treated for gynecologic symptoms (n = 800) and male patients having surgery for benign prostatic hyperplasia (n = 434). The overall health and symptom status of patients in both samples was assessed at enrollment and again 3 months after treatment; at the 3-month follow-up, patients also were asked to compare retrospectively their current health and how they were feeling with their condition before treatment. Findings indicate that prospective and retrospective measures of change do not yield the same results. Retrospective assessments consistently produce higher estimates of the benefits of treatment, although that pattern was clearer for overall health status than for measures of symptoms. Patients' posttreatment health and symptom status contributes as much to retrospective assessments of change as does prospectively measured change, although the retrospective assessments of female patients whose gynecologic symptoms were medically managed were more strongly related to prospective change than those of hysterectomy patients or prostate surgery patients. Overall, we conclude that these alternative measurement strategies yield divergent assessments of change, depending on the type of treatment a patient receives and, to some extent, what is being measured.