Background & Aims

According to the additive model, the placebo response is a part of the response to any analgesic treatment [1]. It is well documents that the communication and interaction between patients and therapists about the treatment could elicited expectations for benefit and improve treatment outcomes [2,3]. However, this knowledge has not yet translated into clinical practice, probably because virtually all evidence arises from experimental studies, or from clinical studies which their results are not informative for routine clinical care. The aim of the current study was to assess the effects of positive information regarding analgesic efficacy on pain and opioids consumption during post-operative recovery.

Methods

Patients undergoing general and otolaryngology surgeries at Ziv Medical Centre were recruited and assigned into the “Regular Communication” or “Enhanced Communication” study arms. During post-surgery recovery, once awake, patients reported their pain level on a Visual Analogue Scale (VAS) every 10 minutes, for 4 times (follow-up of 30 minutes). According to the clinical analgesic protocol, as long as pain is above 6/10, a dose of IV morphine is provided, up to 4 dosages. Participants assigned to the “enhanced communication” received positive information regarding the efficacy of the treatment, while in the “regular communication” study arm, no such information was provided.  A repeated measures ANOVA with 4 different time points and study arm (regular or enhanced communication) was conducted to assess main effects and interactions. To assess differences in medication consumption, t-tests and X2 were conducted.

Results

Out of 128 initially enrolled patients, 102 completed the trial, with 48 in the regular communication arm and 53 in the enhanced communication arm. A repeated measures ANOVA revealed a significant main effect of time (p < 0.001) but not of group (p=0.158 and a significant interaction between time and group (p<0.001, η²=0.145). Total morphine consumption did not differ between groups (p=0.199). However, medication consumption was statistically different across time between groups, with the enhanced communication group showing less opioid consumption at the two last timepoints of assessment (p=0.001).

Conclusions

The information provided to patients by nurses regarding the efficacy of the administrated drug influenced pain and analgesic consumption. The current study results provide direct ecological evidence for the additive value of positive information about opioids efficacy during post-operative recovery. Adding couple of positive sentences about the treatment efficacy could substantially increase the analgesic effect and could reduce the number of morphine dosages. Our hope is that this and other similar studies will assist in translating the powerful placebo effects into routine clinical care.

References

[1] Enck, P., Bingel, U., Schedlowski, M., & Rief, W. (2013). The placebo response in medicine: minimize, maximize or personalize? Nature Reviews. Drug Discovery, 12(3), 191–204. doi:10.1038/NRD3923
[2] Benedetti, F., Carlino, E., & Piedimonte, A. (2016). Increasing uncertainty in CNS clinical trials: the role of placebo, nocebo, and Hawthorne effects. In The Lancet Neurology (Vol. 15, Issue 7, pp. 736–747). Lancet Publishing Group. doi:10.1016/S1474-4422(16)00066-1
[3] Pollo, A., Amanzio, M., Arslanian, A., Casadio, C., Maggi, G., & Benedetti, F. (2001). Response expectancies in placebo analgesia and their clinical relevance. Pain, 93(1), 77–84. doi:10.1016/S0304-3959(01)00296-2

Presenting Author

Issa Limor

Poster Authors

Issa Limor

The Cheryl Spencer Department of Nursing, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel

Lead Author

Karine Beiruti Wiegler

Research Wing, Ziv Medical Center, Safed, Israel

Lead Author

Mariana Agostinho

Master

The Cheryl Spencer Department of Nursing, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel

Lead Author

Roi Treister

The Cheryl Spencer Department of Nursing, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel

Lead Author

Topics

  • Assessment and Diagnosis