Do patients' pre-treatment expectations about acupuncture effectiveness predict treatment outcome in patients with chronic low back pain? A secondary analysis of data from a randomised controlled clinical trial.

OBJECTIVE: This secondary analysis of a randomised controlled patient-blinded trial comparing effectiveness and side effect briefings in patients with chronic low back pain (CLBP) investigated the association between patients' pre-treatment expectations about minimal acupuncture treatment and pain intensity as outcome during and after the end of the treatment. METHODS: Chronic low back pain patients with a pain intensity of at least 4 on a numeric rating scale from 0 to 10 received eight sessions of minimal acupuncture treatment over 4 weeks. The primary outcome was change in pain intensity rated on a Numerical Rating Scale (NRS 0-10) from inclusion visit to treatment session 4 and to the end of the treatment. Patients' expectations about the effectiveness of acupuncture were assessed using the Expectation for Treatment Scale (ETS) before randomization. Linear regression was applied to investigate whether patients' pre-treatment expectations predicted changes in pain intensity during and after treatment. RESULTS: A total of 142 CLBP patients (40.1 ± 12.5 years; 65.5% female) were included in our analysis. Patients' pre-treatment expectations about acupuncture treatment were associated with changes in pain intensity after four sessions of minimal acupuncture treatment (b = -0.264, p = 0.002), but not after the end of the treatment. This association was found in females and males. CONCLUSIONS: Our results imply that higher pre-treatment expectations only lead to larger reductions in pain intensity in the initial phase of a treatment, with a similar magnitude for both females and males. As the treatment progresses in the second half of the treatment, adapted expectations or other non-specific effects might play a more important role in predicting treatment outcome.

Effect of Briefing on Acupuncture Treatment Outcome Expectations, Pain, and Adverse Side Effects Among Patients With Chronic Low Back Pain: A Randomized Clinical Trial.

Importance: In observational studies, patients' treatment outcome expectations have been associated with better outcomes (ie, a placebo response), whereas concerns about adverse side effects have been associated with an in increase in the negative effects of treatments (ie, a nocebo response). Some randomized trials have suggested that communication from clinicians could affect the treatment outcomes by changing patients' expectations. Objective: To investigate whether treatment outcome expectations and reported adverse side effects could be affected by different briefing contents before a minimal acupuncture treatment in patients with chronic low back pain (CLBP). Design, Setting, and Participants: This randomized single-blinded clinical trial was conducted among patients with CLBP at 1 outpatient clinic in Switzerland who had a pain intensity of at least 4 on a numeric rating scale from 0 to 10. Different recruitment channels were used to enroll patients. Data were collected from May 2016 to December 2017 and were analyzed from June to November 2018. Interventions: Patients were randomized to receive either a regular expectation briefing or a high expectation briefing (effectiveness) and either a regular adverse side effect briefing or an intense adverse side effect briefing (adverse side effect) in a 2 × 2 factorial design. The intervention (briefing sessions and written materials) was standardized and delivered before the acupuncture treatment, with additional booster informative emails provided during the 4-week, 8-session acupuncture course. Main Outcomes and Measures: The primary end point was the patients' expectations regarding the effectiveness of the acupuncture treatment (Expectation for Treatment Scale [ETS]) after the briefing and the subsequent pain intensity (numeric rating scale). The primary end point for the adverse side effect briefing was the adverse side effect score at the end of the acupuncture treatment, derived from session-by-session assessments of adverse side effects. Results: A total of 152 patients with CLBP (mean [SD] age, 39.54 [12.52] years; 100 [65.8%] women) were included. The estimated group difference (regular vs high) for the ETS was -0.16 (95% CI -0.81 to 0.50, P = .64), indicating no evidence for a difference between intervention groups. There was also no evidence for a difference in pain intensity at the end of the acupuncture treatment between the groups with different expectation briefings. The adverse side effects score in the group with the intense adverse side effect briefing were estimated to be 1.31 times higher (95% CI, 0.94 to 1.82; P = .11) than after a regular adverse side effect briefing, but the finding was not statistically significant. Conclusions and Relevance: In this study, suggestions regarding treatment benefits (placebo) and adverse side effects (nocebo) did not affect treatment expectations or adverse side effects. Information regarding adverse side effects might require more research to understand nocebo responses. Trial Registration: German Clinical Trials Register Identifier: DRKS00010191.

The influence of personality traits on the placebo/nocebo response: A systematic review.

OBJECTIVE: Some people might be more prone to placebo and nocebo responses than others depending on their personality traits. We aimed to provide a systematic review on the influence of personality traits on placebo and nocebo responses in controlled and uncontrolled studies. METHODS: We conducted a systematic literature search in the databases CINAHL, AMED, PsycINFO and EMBASE for relevant publications published between January 1997 and March 2018. For all included papers, we conducted an additional forward search. RESULTS: After screening 407 references, we identified 24 studies. The Big Five (i.e., neuroticism, extraversion, openness to experience, agreeableness and conscientiousness) and optimism were the most frequently investigated personality traits. Several studies found a positive association between optimism and the placebo response. Furthermore, we found that higher anxiety was associated with increased nocebo responses. CONCLUSION: Evidence points to a possible association between optimism and the placebo response. Therefore, further emphasising the investigation of the influence of optimism on the placebo/nocebo response seems warranted. For clinical practice, the impact of anxiety on the nocebo response might be important to identify patients who might be more prone to experiencing side effects of medical treatments.

Evaluating the Effects of Acupuncture Using a Dental Pain Model in Healthy Subjects - A Randomized, Cross-Over Trial.

Acupuncture is a complementary and nonpharmacological intervention that can be effective for the management of chronic pain in addition to or instead of medication. Various animal models for neuropathic pain, inflammatory pain, cancer-related pain, and visceral pain already exist in acupuncture research. We used a newly validated human pain model and examined whether acupuncture can influence experimentally induced dental pain. For this study, we compared the impact of manual acupuncture (real acupuncture), manual stimulation of a needle inserted at nonacupuncture points (sham acupuncture) and no acupuncture on experimentally induced dental pain in 35 healthy men who were randomized to different sequences of all 3 interventions in a within-subject design. BORG CR10 pain ratings and autonomic responses (electrodermal activity and heart rate variability) were investigated. An initial mixed model with repeated measures included preintervention pain ratings and the trial sequence as covariates. The results showed that acupuncture was effective in reducing pain intensity when compared to no acupuncture (ß = -.708, P = .002), corresponding to a medium Cohen's d effect size of .56. The comparison to the sham acupuncture revealed no statistically significant difference. No differences in autonomic responses between real and sham acupuncture were found during the intervention procedures. PERSPECTIVE: This study established a dental pain model for acupuncture research and provided evidence that experimentally induced dental pain can be influenced by either real acupuncture or manual stimulation of needles at nonacupuncture points. The data do not support that acupoint specificity is a significant factor in reducing experimental pain.

Assessment of patients' expectations: development and validation of the Expectation for Treatment Scale (ETS).

OBJECTIVE: To develop a short self-report instrument for the assessment of expectations (Expectation for Treatment Scale(ETS)) using acupuncture as a case example. DESIGN: A cross-sectional assessment with retest after 1 week. SETTING: A web-based survey with patients suffering from pain. METHODS: In a three-step approach, we reduced the initially collected number of items from 17 to 9 and to 5, including expectations about coping ability, vitality, physical health and reduction of patient complaints. Items were selected according to internal consistency (Cronbach's alpha); convergent and divergent validities with related constructs (optimism, pessimism, resilience, perceived sensitivity to medicines, depression and others); 1-week retest reliability (intraclass correlation coefficient (ICC)); and exploratory and confirmatory factor analysis (CFA). RESULTS: A total of 102 patients suffering from pain were included, and 54 of these patients completed the retest assessment. The final version of the ETS consisted of five items and had an excellent Cronbach's alpha (0.90), with 72.33% variance on one single factor. Depression, pessimism and perceived sensitivity to medicines showed positive correlations with our expectation measure (r=0.23, r=0.20 and r=0.34, respectively); the correlation between the ETS and optimism was low (r=-0.07) and no correlation between the ETS and resilience was found (r=-0.07). Convergent validity was confirmed with a high correlation (r>0.90) between ETS and a treatment-specific measure of expectations. The retest ICC was 0.86, which showed high stability over 1 week. A CFA (n=439) with data from patients with low back pain confirmed the single-factor structure of the instrument. CONCLUSION: The ETS showed strong psychometric properties and covered a distinct construct. As the next step, the ETS might be implemented in different clinical conditions and settings to investigate psychometrics and its predictive power for treatment outcomes.