Abstract Background: Despite the apparent high placebo response rate in randomized placebo-controlled trials (RCT) of patients with irritable bowel syndrome (IBS), little is known about the variability and predictors of this response. Objectives: To describe the magnitude of response in placebo arms of IBS clinical trials and to identify which factors predict the variability of the placebo response. Methods: We performed a meta-analysis of published, English language, RCT with 20 or more IBS patients who were treated for at least 2 weeks. This analysis is limited to studies that assessed global response (improvement in overall symptoms). The variables considered as potential placebo modifiers were study design, study duration, use of a run-in phase, Jadad score, entry criteria, number of office visits, number of office visits/study duration, use of diagnostic testing, gender, age and type of medication studied. Findings: Forty-five placebo-controlled RCTs met the inclusion criteria. The placebo response ranged from 16.0 to 71.4% with a population-weighted average of 40.2%, 95% CI (35.9–44.4). Significant associations with lower placebo response rates were fulfilment of the Rome criteria for study entry (P = 0.049) and an increased number of office visits (P = 0.026). Conclusions: 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.
Introduction: Acupuncture is a complex holistic intervention in which patient–practitioner relationships and healing changes occur in interactive, iterative ways. Qualitative research is one way to capture such complexity. This study sought to understand better the experiences of adolescents involved in acupuncture treatment. Materials and methods: We included a qualitative substudy as part of a pilot randomized sham-controlled study of the use of Japanese acupuncture to treat chronic pelvic pain in adolescent girls. Seven (7) interviews were attained. Themes were double-coded and analyzed using qualitative analysis software. Results: Regardless of treatment arm, all subjects reported positive study-related changes, often attributed to positive qualities of the patient–practitioner relationship. Participants in both the sham and verum acupuncture treatment arms reported in the narratives that they were unsure of their study assignment. In contrast, the study's close-ended success of blinding question suggests that some participants were sure of their treatment allocation. Conclusions: As we continue to study acupuncture using sham controls, we need a better understanding of the possible affects of sham treatments on both treatment outcomes and success of blinding. Qualitative research is one-way to explore subtle emergent changes in participants' experiences.
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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.
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Patient–physician interactions significantly contribute to placebo effects and clinical outcomes. While the neural correlates of placebo responses have been studied in patients, the neurobiology of the clinician during treatment is unknown. This study investigated physicians’ brain activations during patient–physician interaction while the patient was experiencing pain, including a ‘treatment‘, ‘no-treatment’ and ‘control’ condition. Here, we demonstrate that physicians activated brain regions previously implicated in expectancy for pain–relief and increased attention during treatment of patients, including the right ventrolateral and dorsolateral prefrontal cortices. The physician’s ability to take the patients’ perspective correlated with increased brain activations in the rostral anterior cingulate cortex, a region that has been associated with processing of reward and subjective value. We suggest that physician treatment involves neural representations of treatment expectation, reward processing and empathy, paired with increased activation in attention-related structures. Our findings further the understanding of the neural representations associated with reciprocal interactions between clinicians and patients; a hallmark for successful treatment outcomes.
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The scientific discovery of novel training paradigms has yielded better understanding of basic mechanisms underlying cortical plasticity, learning and development. This study is a first step in evaluating Tai Chi (TC), the Chinese slow-motion meditative exercise, as a training paradigm that, while not engaging in direct tactile stimulus training, elicits enhanced tactile acuity in long-term practitioners. The rationale for this study comes from the fact that, unlike previously studied direct-touch tactile training paradigms, TC practitioners focus specific mental attention on the body’s extremities including the fingertips and hands as they perform their slow routine. To determine whether TC is associated with enhanced tactile acuity, experienced adult TC practitioners were recruited and compared to age–gender matched controls. A blinded assessor used a validated method (Van Boven et al. in Neurology 54(12): 2230–2236, 2000) to compare TC practitioners’ and controls’ ability to discriminate between two different orientations (parallel and horizontal) across different grating widths at the fingertip. Study results showed that TC practitioners’ tactile spatial acuity was superior to that of the matched controls (P < 0.04). There was a trend showing TC may have an enhanced effect on older practitioners (P < 0.066), suggesting that TC may slow age related decline in this measure. To the best of our knowledge, this is the first study to evaluate a long-term attentional practice’s effects on a perceptual measure. Longitudinal studies are needed to examine whether TC initiates or is merely correlated with perceptual changes and whether it elicits long-term plasticity in primary sensory cortical maps. Further studies should also assess whether related somatosensory attentional practices (such as Yoga, mindfulness meditation and Qigong) achieve similar effects.
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This study explores two conflictingmodels of how patients experience mind-bodytherapies; these models frame the design of aclinical trial examining the effects of qigong (a traditional Chinese movementtherapy) on the immune systems of former cancerpatients. Data consist of ethnographic researchand in-depth interviews conducted at the Bostonteaching hospital where the trial is to takeplace. These interviews, with biomedicalresearchers who designed the trial and with theqigong master responsible for the qigong arm of the trial, reveal twofundamentally different understandings of howqigong is experienced and how thatexperience may be beneficial. The biomedicalteam sees qigong as a non-specifictherapy which combines relaxation and exercise. The qigong master, on the other hand,sees qigong as using specific movementsand visualizations to direct mental attentionto specific areas of the body. Thus while thebiomedical team frames qigong as a“mind-body” practice, the qigong masterframes it as a “mind-in-body” practice. This research suggests that the biomedicalnotion that mind-body therapies work byeliciting mental relaxation is only one way ofthinking about how patients experiencemodalities like qigong: indeed,characterizations of mind-body therapies whichemphasize a mental sense of relaxation may bespecific to biomedicine and the cultures whichsurround it. More broadly, the paper arguesthat gaps in understanding between researchersand practitioners may be hindering scientificefforts to assess therapies like qigong.It concludes by proposing that clinical trialsof traditional and alternative therapies buildethnographic inquiry about practitionerexperience into the design process.
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OBJECTIVES: This study aimed to compare the effects of true and sham acupuncture in relieving symptoms of irritable bowel syndrome (IBS).
METHODS: A total of 230 adult IBS patients (75% females, average age: 38.4 years) were randomly assigned to 3 weeks of true or sham acupuncture (6 treatments) after a 3-week "run-in" with sham acupuncture in an "augmented" or "limited" patient–practitioner interaction. A third arm of the study included a waitlist control group. The primary outcome was the IBS Global Improvement Scale (IBS-GIS) (range: 1–7); secondary outcomes included the IBS Symptom Severity Scale (IBS-SSS), the IBS Adequate Relief (IBS-AR), and the IBS Quality of Life (IBS-QOL).
RESULTS: Although there was no statistically significant difference between acupuncture and sham acupuncture on the IBS-GIS (41 vs. 32%, P=0.25), both groups improved significantly compared with the waitlist control group (37 vs. 4%, P=0.001). Similarly, small differences that were not statistically significant favored acupuncture over the other three outcomes: IBS-AR (59 vs. 57%, P=0.83), IBS-SSS (31 vs. 21%, P=0.18), and IBS-QOL (17 vs. 13%, P=0.56). Eliminating responders during the run-in period did not substantively change the results. Side effects were generally mild and only slightly greater in the acupuncture group.
CONCLUSIONS: This study did not find evidence to support the superiority of acupuncture compared with sham acupuncture in the treatment of IBS.
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