Nocebo Effects on Muscular Performance – An Experimental Study About Clinical Situations

Abstract

Introduction: Nocebo effects are not only seen in studies of pharmacology and placebo/nocebo research but also in clinical everyday situations. For generation of objective and quantitative data on the impact of negative communication we have evaluated the immediate effects of common sentences, non-verbal signals and situations in the medical context on muscular performance.Methods: In an experimental study, 46 volunteers were tested by dynamometry of the deltoid muscle group to evaluate the maximal muscular strength during arm abduction. Baseline values were compared to performance after exposure to 18 verbal and non-verbal suggestions. Suggestions suspected to be negative were alternated with and compared to positively formulated alternatives.Results: Verbal and non-verbal communication produced significant effects on muscular performance, resulting mainly in weakening. The decrease in muscle strength after risk information for informed consent (91.4% of baseline) was absent, when benefits of the treatment were named coincidently. The weakening effect of asking about “pain” and “nausea” (89.4%), and of the announcement of medical interventions (91.7%) could be avoided with alternative wording. Impairment of muscular performance was also observed with the nocebo-inducers negative memory (89.5%) or uncertain future (93.3%), in contrast to a positive memory or the orientation into the presence. Non-verbal suggestions like overhead anesthesia induction (89.9%), a transport in strict flat supine position (89.1%), or a view from the window to a parking lot (94.1%) significantly reduced maximal muscle strength, whereas face-to face induction, half-sitting position and a view into the landscape did not. 8 out of 9 tested clinical situations reduced maximal arm muscle strength significantly, whereas alternative formulations did not.Conclusion: This study describes a quick, simple and uniform test using objective measurement of maximal muscle strength to allow for identification, quantification, and comparison of negative suggestions, regardless of their specific content and effect. Muscle strength is a clinically relevant parameter with regard to early mobilization, risk of falling and sufficient breathing. Furthermore, the observed impairment of muscular performance could reflect a general “weakening effect” of negative suggestions. In addition, the test facilitates development and verification of appropriate alternatives to prevent nocebo effects in patients, thereby improving patient communication.

Time-Dependent Negative Effects of Verbal and Non-verbal Suggestions in Surgical Patients—A Study on Arm Muscle Strength

“…These relative values were used to respect the high variance of muscle strength between individuals. Maximal muscle strength measured under these conditions is a rather robust physiological parameter with an expected variation of ±6.3% from baseline (Zech et al, 2019). All patients were tested by the same examiner (M.Sch.).…”

“…With maximal arm muscle strength, we found a measurement fulfilling this criterion. In a study on healthy volunteers, we tested nine verbal or visual suggestions from everyday clinical practice in two versions and found a significant reduction in a performance that may be interpreted as marker for a "weakening" of the patient (Zech et al, 2019). Alternative formulations of these suggestions were able to neutralize the observed nocebo effect.…”

“…Maximal muscle strength under suggestions was measured at two time points: days before surgery (T1, minimum 3 days, median at day 3, 53% at day 3, the rest distributed around day 6 before surgery) and in the evening before surgery (T2). Maximal isometric contraction of the deltoid muscle group was tested by dynamometry in a defined upright position with the dominant arm stretched out laterally, as described previously (Zech et al, 2019). A dynamometer (FORCE GAUGE FM200, PCE Deutschland GmbH, Meschede, Germany) with a capacity of 196.0 N and a resolution of 0.05 N was used in the peak hold mode.…”

“…The same suggestions out of clinical context were tested as in a previous study on healthy volunteers (Zech et al, 2019). Patients listened to recorded instructions explaining the placement and functionality of the muscle test, whereas suggestions were given verbally, face to face.…”

Putting the ‘Art’ Into the ‘Art of Medicine’: The Under-Explored Role of Artifacts in Placebo Studies

“…Based on the conceptual outline summarized above, we suggest that a preliminary experimental framework explore a classical conditioning paradigm to manipulate whether conspicuous artifacts or the apparel of a physician augment or diminish placebo effects. While much of the research we cover focuses on subjective outcomes, research ought to consider incorporating objective measures (e.g., behavior) [e.g., Zech et al (2019)]. In addition, as we describe in more detail below, we suggest there may be significant promise in focusing on how artifacts influence expectancies and mindsets in clinical encounters.…”