The role of expectations in patients' reports of post-operative outcomes and improvement following therapy.

Outcomes research typically focuses on the technical capabilities associated with treatment that predicts patients' post-therapy outcomes adjusting for health-related factors. Research on the ability of placebo therapy to alter outcomes suggests that a patient's expectations about therapy can also influence outcomes. Few studies have examined the effects of expectations and their implications for assessing outcomes. This study followed 348 patients who had surgery for benign prostatic hyperplasia. Four hypotheses are tested: whether positive expectations about improvement influence: 1) patients' postoperative reports of symptoms; 2) their belief that they have improved; 3) their overall health after treatment; and 4) whether these effects persist during the year following treatment. Using step-wise regression to control for sociodemographic and clinical factors, we found positive expectations did not appear to strongly influence a patient's report of postoperative symptoms or their overall health. However, we found strong support for positive expectations increasing the likelihood of reporting they felt better after surgery, even after controlling for symptom changes. This effect persisted throughout the postoperative year. We conclude that positive expectations result in a more optimistic view of improvement after surgery rather than altering reports of outcomes or health.