Objective To investigate whether a sham device (a validated sham acupuncture needle) has a greater placebo effect than an inert pill in patients with persistent arm pain. Design A single blind randomised controlled trial created from the two week placebo run-in periods for two nested trials that compared acupuncture and amitriptyline with their respective placebo controls. Comparison of participants who remained on placebo continued beyond the run-in period to the end of the study. Setting Academic medical centre. Participants 270 adults with arm pain due to repetitive use that had lasted at least three months despite treatment and who scored ≥ 3 on a 10 point pain scale. Interventions Acupuncture with sham device twice a week for six weeks or placebo pill once a day for eight weeks. Main outcomemeasures Arm pain measured on a 10 point pain scale. Secondary outcomes were symptoms measured by the Levine symptom severity scale, function measured by Pransky's upper extremity function scale, and grip strength. Results Pain decreased during the two week placebo run-in period in both the sham device and placebo pill groups, but changes were not different between the groups ( − 0.14, 95% confidence interval − 0.52 to 0.25, P = 0.49). Changes in severity scores for arm symptoms and grip strength were similar between groups, but arm function improved more in the placebo pill group (2.0, 0.06 to 3.92, P = 0.04). Longitudinal regression analyses that followed participants throughout the treatment period showed significantly greater downward slopes per week on the 10 point arm pain scale in the sham device group than in the placebo pill group ( − 0.33 ( − 0.40 to − 0.26) v − 0.15 ( − 0.21 to − 0.09), P = 0.0001) and on the symptom severity scale ( − 0.07 ( − 0.09 to − 0.05) v − 0.05 ( − 0.06 to − 0.03), P = 0.02). Differences were not significant, however, on the function scale or for grip strength. Reported adverse effects were different in the two groups. Conclusions The sham device had greater effects than the placebo pill on self reported pain and severity of symptoms over the entire course of treatment but not during the two week placebo run in. Placebo effects seem to be malleable and depend on the behaviours embedded in medical rituals.

BACKGROUND: There are limited data on the characteristics of yoga users in the U.S. OBJECTIVE:To characterize yoga users, medical reasons for use, perceptions of helpfulness, and disclosure of use to medical professionals. METHODS:Utilizing cross-sectional survey data from the 2002 National Health Interview Survey (NHIS) Alternative Medicine Supplement (n=31044), we examined correlates of yoga use for health. The estimated prevalence from 2002 NHIS of yoga for health was 5.1% corresponding to over 10 million adults. RESULTS:In 2002, yoga users were predominately Caucasian (85%) and female (76%) with a mean age of 39.5 years. Compared to non-yoga users, yoga users were more likely female (OR 3.76, 95% CI 3.11-4.33); less likely black than white (OR 0.65, 95% CI 0.53-0.80); tended to be younger; and more likely college educated (OR 2.70, 95% CI 2.37-3.08). Musculoskeletal conditions (OR 1.61, 95% CI 1.42-1.83), mental health conditions (OR 1.43, 95% CI 1.22-1.67), severe sprains in the last 12 months (OR 1.49, 95% CI 1.22-1.81), and asthma (OR 1.27, 95% CI 1.05-1.54) were independently associated with higher yoga use, while hypertension (OR 0.78, 95% CI 0.64-0.95) and chronic obstructive lung disease (OR 0.69, 95% CI 0.48-1.00) were associated with lower use. Yoga was most commonly used to treat musculoskeletal or mental health conditions, and most users reported yoga to be helpful for these conditions. A majority of yoga users (61%) felt yoga was important in maintaining health, though only 25% disclosed yoga practice to their medical professional. CONCLUSIONS:We found that yoga users are more likely to be white, female, young and college educated. Yoga users report benefit for musculoskeletal conditions and mental health, indicating that further research on the efficacy of yoga for the treatment and/or prevention of these conditions is warranted.KEY WORDS: yoga; complementary and alternative medicine (CAM); behavioral medicine.

Placebo effects in IBS clinical trials measuring a global outcome are highly variable. Entry criteria and number of office visits are significant predictors of the placebo response. More stringent entry criteria and an increased number of office visits appear to independently decrease the placebo response.