The online version of this article (doi:10.1186/s12916-016-0767-3) contains supplementary material, which is available to authorized users.
Placebo effects contribute substantially to outcome in most fields of medicine. While clinical trials typically try to control or minimize these effects, the potential of placebo mechanisms to improve outcome is rarely used. Patient expectations about treatment efficacy and outcome are major mechanisms that contribute to these placebo effects. We aimed to optimize these expectations to improve outcome in patients undergoing coronary artery bypass graft (CABG) surgery.
In a prospective three-arm randomized clinical trial with a 6 month follow-up, 124 patients scheduled for CABG surgery were randomized to either a brief psychological pre-surgery intervention to optimize outcome expectations (EXPECT); or a psychological control intervention focusing on emotional support and general advice, but not on expectations (SUPPORT); or to standard medical care (SMC). Interventions were kept brief to be feasible with a heart surgery environment; “dose” of therapy was identical for both pre-surgery interventions. Primary outcome was disability 6 months after surgery. Secondary outcomes comprised further clinical and immunological variables.
Patients in the EXPECT group showed significantly larger improvements in disability (−12.6; −17.6 to −7.5) than the SMC group (−1.9; −6.6 to +2.7); patients in the SUPPORT group (−6.7; −11.8 to 1.7) did not differ from the SMC group. Comparing follow-up scores and controlling for baseline scores of EXPECT versus SUPPORT on the variable disability only revealed a trend in favor of the EXPECT group (P = 0.09). Specific advantages for EXPECT compared to SUPPORT were found for mental quality of life and fitness for work (hours per week). Both psychological pre-surgery interventions induced less pronounced increases in pro-inflammatory cytokine concentrations reflected by decreased interleukin-8 levels post-surgery compared to changes in SMC patients and lower interleukin-6 levels in patients of the EXPECT group at follow-up. Both pre-surgery interventions were characterized by great patient acceptability and no adverse effects were attributed to them. Considering the innovative nature of this approach, replication in larger, multicenter trials is needed.
Optimizing patients’ expectations pre-surgery helps to improve outcome 6 months after treatment. This implies that making use of placebo mechanisms has the potential to improve long-term outcome of highly invasive medical interventions. Further studies are warranted to generalize this approach to other fields of medicine.
Ethical approval for the study was obtained from the IRB of the Medical School, University of Marburg, and the trial was registered at (NCT01407055) on July 25, 2011.
Additional file 1: Figure S4. Individual courses of disability scores in the three treatment conditions. Figure S5. a: Quality of Life (mental). b: Anxiety. c: Depression. Table S3. Means and percentages of patients’ medication at hospital admission for Standard Medical Care (SMC), Supportive Therapy (SUPPORT) or Expectation Manipulation Intervention (EXPECT). Table S4. Means and percentages of patients’ medication at hospital discharge for Standard Medical Care (SMC), Supportive Therapy (SUPPORT) or Expectation Manipulation Intervention (EXPECT). Table S5. Further outcome variables. (DOC 283 kb)12916_2016_767_MOESM1_ESM.doc
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- Preoperative optimization of patient expectations improves long-term outcome in heart surgery patients: results of the randomized controlled PSY-HEART trial
Meike C. Shedden-Mora
Johannes A. C. Laferton
Keith J. Petrie
- BioMed Central
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