[Treatment expectations for postoperative pain]

Preoperative treatment expectations have a significant influence on postoperative pain and treatment outcomes. Positive expectations are an important mechanism of the placebo effect and negative expectations are an important mechanism of the nocebo effect.

What is the influence of treatment expectations, how are they assessed in the clinical setting, and how can the findings be implemented in clinical practice?

A literature search was performed using the keywords "expectation" AND ("postoperative" OR "surgery"). All English and German articles were selected. In addition, the bibliographies of the articles found were examined and incorporated.

A total of 158 articles were found, 49 of which investigate expectations and include postoperative treatment outcomes. Most articles investigate expectations only at baseline to ensure that groups do not differ preoperatively. The studies that prospectively examine the influence of expectations apply very different measurement methods to investigate expectancy constructs. Thus, comparison across studies is difficult. There are few studies examining whether and how expectations can be influenced perioperatively, and who developed practice-relevant interventions to change them.

Valid and reliable measurement tools should be applied in clinical trials for a more robust investigation of treatment expectations. Further studies should address possible intervention options so that treatment expectations can also be incorporated into standard clinical care.