Reduction of postoperative pain and swelling by ultrasound treatment: a placebo effect

Placebo Effects: Neurological Mechanisms Inducing Physiological, Organic, and Belief Responses-A Prospective Analysis

The placebo effect can induce physiological or clinical neurological and organic responses despite the recipient receiving no active ingredients; these responses are based instead on the recipient's perceptions. Placebo effects come from the rostral anterior cingulate cortex, pontine nucleus, and cerebellum of the brain; this information provides a better understanding of placebo effects and can also help us understand the mechanism of the modulation of neurotransmitters from the use of psychedelic substances, activity of selective serotonin reuptake inhibitors, the process of transcranial magnetic stimulation, and deep brain stimulation, as well as aid in developing novel therapies, challenging the validity of controlled clinical trials (RCTs) that the regulatory agencies now appreciate. Education about how placebo effects bring in social, political, and religious beliefs and whether these can be modulated may help reduce global confrontations.

The Effects of Connective Tissue Manipulation in Primary Dysmenorrhea: a Randomized Placebo-Controlled Study

The aim of this study was to identify the effects of connective tissue manipulation (CTM) in primary dysmenorrhea (PD) in a randomized, placebo-controlled design. Thirty-eight nulliparous women with PD were randomly allocated into 3 groups: CTM (n = 13), placebo therapeutic ultrasound (US) (n = 13), and control (n = 12). The primary outcome measure was the maximum and mean menstrual pain intensity at the last menstrual period on the visual analogue scale (VAS). Secondary outcome measures were menstrual symptom frequency and distress score, the number of analgesic/anti-inflammatory drugs used during the last menstrual period, and perception of improvement in dysmenorrhea severity via interventions. The chi-square test and analysis of variance were used to determine within-group and between-group differences. Statistical significance level was determined as p < 0.05. Compared with the placebo US and control groups, it was observed that menstrual pain (VAS mean and VAS maximum), menstrual symptom frequency, and distress level decreased more after treatment (T2) and the 3-month follow-up (T3) in de CTM group (p < 0.001, p = 0.001, p = 0.014, p = 0.015, respectively). There was no difference between the groups in terms of analgesic/anti-inflammatory drugs use (p > 0.05). The rate of individuals reporting perceived improvement at the end of intervention period was higher in the CTM group than in the placebo-US and control groups (p < 0.001). In the 3rd month follow-up, there was no difference between groups in the perception of improvement (p > 0.05). CTM is superior to placebo intervention and control in improving menstrual pain and other menstrual symptoms in PD in the short-term. On the other hand, when the application is terminated, this superiority seems to disappear during the follow-up period.

Effects of Scooping Mobilization and Muscle Energy Technique on Pain and Range of Motion in Post-fracture Elbow Stiffness: A Case Report

Olecranon fractures are breaks in the elbow's bony tip. One of the three bones that come together to form the elbow joint is the ulna, which is made up of this pointed section of bone. The olecranon prevents the ulna from anteriorly translating relative to the terminal humerus. Olecranon fractures can result either indirectly or directly from trauma. The posterior point of the elbow may be directly fractured following a fall or severe injury. Extreme activation of the triceps muscle following a fall on a partly extended elbow may result in indirect avulsion of the olecranon. First, the most typical method of identifying a fracture is with the use of an x-ray, while magnetic resonance imaging (MRI) allows for the detection and confirmation of soft tissue involvement. Physiotherapeutic treatment assists in pain relief, extending the range of motion, and quick healing. Early intervention after open reduction and internal fixation reduces post-fracture stiffening. The readership of the research study is intended to be informed regarding the various treatments available for elbow extensor lag and post-fracture elbow stiffness. This report offers suggestions to improve the patient's care and functionality after an olecranon fracture.

Abdominal Massage in Functional Chronic Constipation: A Randomized Placebo-Controlled Trial

OBJECTIVE

The aim of this study was to investigate the effects of abdominal massage on the severity of constipation, bowel function, and quality of life (QoL) in patients with functional chronic constipation in a randomized placebo-controlled design.

METHODS

Seventy-four patients diagnosed with functional constipation according to the Rome IV diagnostic criteria were included. Patients were randomly assigned to the intervention group (abdominal massage plus lifestyle advice) or the control group (placebo therapeutic ultrasound plus lifestyle advice). Abdominal massage or placebo ultrasound was applied for 4 weeks. The primary outcome measure was the Constipation Severity Instrument score. Bowel diary data and the Patient Assessment of Constipation Quality of Life Questionnaire score were used as secondary outcome measures. Differences in outcome measures within and between groups were analyzed by repeated-measures analysis of variance.

RESULTS

Although constipation severity, bowel function indicators (defecation frequency and duration and stool consistency), and QoL were found to improve significantly over time in both groups, improvements in both primary and secondary outcomes were much more significant in the abdominal massage group. In addition, group × time interaction effects were found to be significant for constipation severity, bowel function findings, and QoL. There were approximately 70% and 28% reductions in constipation severity, 56% and 38% improvement rates in QoL, and 70% and 43% increases in defecation frequency in the intervention and placebo groups, respectively.

CONCLUSION

Abdominal massage should be one of the first-line conservative approaches in the management of functional chronic constipation. Further randomized placebo-controlled studies with long-term follow-up are needed.

IMPACT

For functional constipation, which is a common gastrointestinal problem, abdominal massage should be considered as an option in first-line therapy because of its effect beyond the placebo effect.

LAY SUMMARY

If you have functional constipation, your physical therapist may be able to provide abdominal massage to help reduce your symptoms.

Placebo response and effect in randomized clinical trials: meta-research with focus on contextual effects

BACKGROUND

Contextual effects (i.e., placebo response) refer to all health changes resulting from administering an apparently inactive treatment. In a randomized clinical trial (RCT), the overall treatment effect (i.e., the post-treatment effect in the intervention group) can be regarded as the true effect of the intervention plus the impact of contextual effects. This meta-research was conducted to examine the average proportion of the overall treatment effect attributable to contextual effects in RCTs across clinical conditions and treatments and explore whether it varies with trial contextual factors.

METHODS

Data was extracted from trials included in the main meta-analysis from the latest update of the Cochrane review on "Placebo interventions for all clinical conditions" (searched from 1966 to March 2008). Only RCTs reported in English having an experimental intervention group, a placebo comparator group, and a no-treatment control group were eligible.

RESULTS

In total, 186 trials (16,655 patients) were included. On average, 54% (0.54, 95%CI 0.46 to 0.64) of the overall treatment effect was attributable to contextual effects. The contextual effects were higher for trials with blinded outcome assessor and concealed allocation. The contextual effects appeared to increase proportional to the placebo effect, lower mean age, and proportion of females.

CONCLUSION

Approximately half of the overall treatment effect in RCTs seems attributable to contextual effects rather than to the specific effect of treatments. As the study did not include all important contextual factors (e.g., patient-provider interaction), the true proportion of contextual effects could differ from the study's results. However, contextual effects should be considered when assessing treatment effects in clinical practice.

TRIAL REGISTRATION

PROSPERO CRD42019130257 . Registered on April 19, 2019.

Neuron-Glia-Immune Triad and Cortico-Limbic System in Pathology of Pain

Pain is an unpleasant sensation that alerts one to the presence of obnoxious stimuli or sensations. These stimuli are transferred by sensory neurons to the dorsal root ganglia-spinal cord and finally to the brain. Glial cells in the peripheral nervous system, astrocytes in the brain, dorsal root ganglia, and immune cells all contribute to the development, maintenance, and resolution of pain. Both innate and adaptive immune responses modulate pain perception and behavior. Neutrophils, microglial, and T cell activation, essential components of the innate and adaptive immune responses, can play both excitatory and inhibitory roles and are involved in the transition from acute to chronic pain. Immune responses may also exacerbate pain perception by modulating the function of the cortical-limbic brain regions involved in behavioral and emotional responses. The link between an emotional state and pain perception is larger than what is widely acknowledged. In positive psychological states, perception of pain along with other somatic symptoms decreases, whereas in negative psychological states, these symptoms may worsen. Sex differences in mechanisms of pain perception are not well studied. In this review, we highlight what is known, controversies, and the gaps in this field.

Therapeutic Ultrasound for Chemotherapy-Related Pain and Sensory Disturbance in the Hands and Feet in Patients With Colorectal Cancer: A Pilot Randomized Controlled Trial

CONTEXT

This proof-of-concept trial was undertaken as a first step in exploring the clinical benefit of therapeutic ultrasound for pain and sensory disturbance in patients with colorectal cancer.

OBJECTIVES

The aim of this study was to determine the feasibility and preliminary efficacy of adding therapeutic ultrasound to a home-based therapeutic exercise program (current standard of care) for patients presenting with oxaliplatin-related pain and sensory disturbance in the hands and feet.

METHODS

Thirty-one colorectal cancer patients with presenting symptoms of peripheral sensory neuropathy, based on a physician-rated grade 1, 2, or 3 on the National Cancer Institute Common Terminology Criteria for Adverse Events for sensory and motor neuropathy, were enrolled in the trial. Patients were randomized to either 10 sessions of ultrasound therapy intervention over two-week period (continuous ultrasound at an intensity of 0.7 to 0.8 w/cm², and frequency of 3 MHz for 5 minutes) plus standard care (n = 16) or to standard care alone (n = 15). The feasibility of therapeutic ultrasound was determined by the recruitment rate, participants' adherence to the intervention, and the study completion rates. Assessments of pain, sensory disturbance, sensation, and balance were conducted at baseline, two and six weeks.

RESULTS

We achieved a recruitment rate of 84%, an adherence rate of 100% to the intervention, and a completion rate of 100%. Adding therapeutic ultrasound to standard care resulted in a statistically and clinically significant improvement in symptoms of pain and sensory disturbance (P = 0.003) at two weeks; however, no significance difference between the groups was found at the six-week follow-up.

CONCLUSIONS

The findings of this proof-of-concept study support the feasibility of the therapeutic ultrasound in addition to standard care as an intervention for colorectal cancer patients with oxaliplatin-related pain and sensory disturbance in the hands and feet. The findings warrant a large-scale placebo-controlled trial.

The Influence of Verbal Suggestion on Post-Needling Soreness and Pain Processing after Dry Needling Treatment: An Experimental Study

BACKGROUND

It remains unclear as to whether verbal suggestions and expectancies can influence the perception of post-needling soreness. The aim of this study was to analyze the effects of verbal suggestions on post-needling soreness after dry needling of the trapezius muscle.

METHODS

This study is a randomized controlled trial including healthy subjects randomly assigned to one of three groups receiving different verbal suggestions about the effects of dry needling and the occurrence of post needling soreness (positive, negative, or neutral). Then, dry needling on a latent trigger point of the upper trapezius muscle was performed and the following outcomes were measured immediately after, 24, 48, and 72 h, and one week after the intervention: post-needling soreness intensity, pressure pain threshold (PPT), temporal summation (TS) and conditioned pain modulation (CPM).

RESULTS

Seventy-three consecutive participants were screened and 42 participants (12 men and 30 women, aged: 24 ± 8 years old) were eligible and finished the study protocol. The results showed that verbal suggestion did not influence the perception of post-needling soreness, since there were no differences between groups (p < 0.05) on the intensity of post-needling soreness or tenderness over a one-week follow-up. Moreover, verbal suggestion did not associate with changes in sensorimotor variables of TS and CPM.

CONCLUSIONS

The induction of different types of expectations through verbal suggestion does not influence the perception of acute pain perceived during the performance of a deep dry needling technique and post-needling pain or soreness after deep dry needling on a latent upper trapezius myofascial trigger point (MTrP).

Efficacy and safety of novel low-intensity pulsed ultrasound (LIPUS) in treating mild to moderate erectile dysfunction: a multicenter, randomized, double-blind, sham-controlled clinical study

Background

In our previous study, a novel low-intensity pulsed ultrasound (LIPUS) therapeutic device has been shown to improve erectile function non-invasively in a diabetic-induced erectile dysfunction (ED) animal model.

Methods

In order to investigate the efficacy and safety of LIPUS in the clinical treatment of patients with ED, a multicenter, randomized, double-blind, sham-treated, controlled clinical study was conducted at five medical centers, and 120 patients with mild to moderate ED were enrolled in the study. Patients were randomized into a sham-treated control group (40 patients) or a LIPUS-treated group (80 patients). LIPUS or sham treatment was applied to both sides of the penis shaft and crus for 5 min in each area, twice a week for four weeks. Assessment of efficacy and safety were evaluated using IIEF-5, Sexual Encounter Profile (SEP)-questionnaires 2/3, Global Assessment Question (GAQ), Erectile Hardness Score (EHS), Erection Quality Scale (EQS) score, and pain assessment [Visual Analogue Scale/Score (VAS)].

Results

Ten patients in LIPUS treatment group and 6 patients in sham treatment control group were excluded and the dropout rate is 13.33%. Response to treatment was identified as IIEF-5 score increased more than 2/3/4 points of post-treatment (12W) compared to pre-treatment (0W). The response rate in treatment group was 54/80 (67.50%), which was significantly higher than control group 8/40 (20.00%) at 12 weeks (FAS analysis). The percentage of patients with positive answers to SEP-3 (successful vaginal intercourse) were 58.97%, 64.1%, and 73.08% 4, 8, and 12 weeks after treatment which were significantly higher than 28.95%, 31.58%, and 28.95% respectively in control group (FAS, P<0.05). The positive responsive rates for GAQ in treatment group were about 2 to 3 times of that in control group (P<0.05). No treatment-related adverse events (AEs) were found, including local petechia or ecchymosis and hematuria.

Conclusions

Current study indicates that LIPUS can safely and effectively treat patients with mild to moderate ED without significant AEs, which is related to the mechanical force of LIPUS and can restore the pathological changes of the corpus cavernosum. LIPUS is a promising alternative treatment for ED treatment in the near future, while further research is remanded.

From Bench to Bedside: Converting Placebo Research into Belief Activation

Research on the placebo effect contains important elements that can be harnessed to improve clinical care. This paper proposes a new term, "Belief Activation," to describe the deliberate use of placebo effect tools by both patients and clinicians to catalyze healing. Belief Activation includes, but is not limited to, maximizing patient and practitioner expectations, classical and social conditioning, spirituality and prayer/intention, therapeutic relationship, healing environments, and minimizing the nocebo effect. This paper demonstrates ways in which Belief Activation is a form of evidence-based medicine and seeks to translate knowledge from placebo research into medical practice.

Effects of underwater ultrasound therapy on pain, inflammation, hand function and quality of life in patients with rheumatoid arthritis - a randomized controlled trial

•

Underwater ultrasound therapy is a useful procedure to treat inflammation in patients with RA.

•

Underwater ultrasound therapy is suitable to treat irregular body parts, because the transmission coefficient is high and the reflection is low in water.

•

The improvements were only observed in the short term (at the end of 2 weeks of treatment).

Objectives

To investigate the effects of underwater ultrasound (US) therapy in 48 patients with moderately active rheumatoid arthritis (disease activity score in 28 joints [DAS28] > 3.2 and < 5.1).

Methods

Patients randomly assigned to the ultrasound group (n = 25) received underwater continuous ultrasound therapy to both wrists and hands for 7 min per session with an intensity of 0.7 W/cm² for 10 sessions. The control group (n = 23) received sham treatment under the same conditions. At baseline, at the end of treatment (end of Week 2) and at the follow-up visit (Week 14), the following outcomes were evaluated: disease activity (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], tender and swollen joint counts, pain on a visual analog scale, DAS28, hand function (fist making, wrist extension and flexion, hand grip strength) and quality of life (Health Assessment Questionnaire [HAQ]).

Results

A significant decrease in C-reactive protein at the end of Week 2 and Week 14 compared to control group (mean between-group difference at 2 weeks = −5.77, 95% CI = −10.86 to −0.68, mean between-group difference at 14 weeks = −5.07, 95% CI = −10.13 to −0.01), and non-significant decrease in DAS28 was observed. By the end of treatments at the end of week 2, ultrasound alleviated pain significantly (mean between-group difference at two weeks = −8.35 95% CI = −16.12 to −0.58), as well as improved left wrist extension compared to the control group (mean between-group difference at 14 weeks = 4.35, 95% CI = 1.09–7.60).

Conclusion

Underwater ultrasound therapy was better than sham treatment at the end of 2 weeks of treatment, but not at long term (14 weeks) in patients with rheumatoid arthritis.

Clinical trial registration number: NCT02706028 (https://clinicaltrials.gov/ct2/show/NCT02706028)

An enactive account of placebo effects

Placebos are commonly defined as ineffective treatments. They are treatments that lack a known mechanism linking their properties to the properties of the condition on which treatment aims to intervene. Given this, the fact that placebos can have substantial therapeutic effects looks puzzling. The puzzle, we argue, arises from the relationship placebos present between culturally meaningful entities (such as treatments or therapies), our intentional relationship to the environment (such as implicit or explicit beliefs about a treatment's healing powers) and bodily effects (placebo responses). How can a mere attitude toward a treatment result in appropriate bodily changes? We argue that an 'enactive' conception of cognition accommodates and renders intelligible the phenomenon of placebo effects. Enactivism depicts an organism's adaptive bodily processes, its intentional directedness, and the meaningful properties of its environment as co-emergent aspects of a single dynamic system. In doing so it provides an account of the interrelations between mind, body and world that demystifies placebo effects.

Placebo Treatment for Varicosity: Don't Eat It, Rub it!

Objective:

To define and compare the clinical effectiveness of two different placebo applications, oral and topical, in the management of primary varicose veins.

Design:

Prospective, controlled trial with two parallel treatment groups.

Setting:

Social security system related rehabilitation centre in Germany with nationwide assignment of inpatients.

Patients:

Sixty-one patients with the clinical diagnosis of varicose veins.

Interventions:

Group A ( n = 30) received an oral placebo, group B ( n = 31) applied a topical placebo preparation to both legs. The treatment period was 24 days; both therapies were applied daily.

Main outcome measures:

Foot volume, ankle circumference, light reflex rheography and subjective complaints.

Results:

In both groups there were significant improvements in several outcome measures concerning both objective signs and subjective symptoms. Light reflex rheography yielded significantly better results in the topically compared with the orally treated group. Other variables followed this trend without, however, reaching the level of statistical significance.

Conclusions:

Symptoms of varicose veins are highly prone to respond to placebo. There are some indications to suggest that a topical placebo induces stronger effects than an oral one.

The Signaling Theory of Symptoms : An Evolutionary Explanation of the Placebo Effect

Placebo research shows that the subjective quality of care and social support, as well as the patients' expectations of treatment, influence therapeutic outcomes. However, this phenomenon, known as the placebo effect, does not usually cure the disease, but rather can provide symptomatic relief: It may soothe symptoms such as pain, swelling, or nausea that constitute part of an immune response. The function of this mechanism remains unclear. This article puts forward the Signaling Theory of Symptoms (STS) as a possible explanation. According to STS, discernible aspects of an immune response, such as pain, swelling, or nausea, not only serve a defensive and healing function but also a signaling function: symptoms signal the need for care and treatment to potential helpers. Once help and treatment are granted, the signaling function is fulfilled and the symptoms diminish. This mechanism may have been a significant advantage in preindustrial environments, when sufferers depended on extensive social support and personal treatment. Nowadays, from the point of view of modern materialist medicine, the mobilization of social support no longer seems so crucial, and thus the placebo effect has been assigned a somewhat mysterious quality.

Association between physician beliefs regarding assigned treatment and clinical response: re-analysis of data from the Hypericum Depression Trial Study Group

BACKGROUND

We have previously shown an association between patient belief and treatment response in the Hypericum Depression Trial Study Group's 2002 study. We re-examined these data to determine whether clinical improvement was associated with physician belief about assigned therapy.

METHODS

Three hundred and forty adults with major depression and baseline scores ≥20 on the 17-item Hamilton Depression Scale (HDRS-17) were randomized to Hypericum 900-1500mg/day, sertraline 50-100mg/day, or placebo for 8 weeks. At week 8, physicians guessed their patients' treatment. We analyzed 277 subjects with at least one post-baseline visit and physician guess data. We examined association between guess and improvement in HDRS-17 and whether treatment assignment moderated the effect of belief on remission (final HDRS-17 score <8).

RESULTS

Patient and doctor guesses agreed at 53% for sertraline, 68% for Hypericum, and 52% for placebo (kappa=0.37). Doctors guessed placebo correctly (38%) more than sertraline (18%) or Hypericum (19%) (p=0.001). Adverse event scores were significantly greater among subjects for which the clinicians guessed Hypericum (p<0.001) or sertraline (p=0.005) compared to placebo. Significant improvements in HDRS-17 score were found when comparing the Hypericum-guess (p<0.001) or the sertraline-guess group (p<0.001) against the placebo-guess group. Remission rates were significantly greater for subjects whose clinicians guessed sertraline (p<0.001) or Hypericum (p<0.001) versus placebo.

CONCLUSION

Doctors tended to guess placebo more easily than Hypericum or sertraline, and their guesses tended to favor active therapies when improvement was more robust. Results show association but not causation, and merit more careful investigation.

Prospective, randomized, open-label, pilot clinical trial comparing the effects of dexamethasone coadministered with diclofenac potassium or acetaminophen and diclofenac potassium monotherapy after third-molar extraction in adults

BACKGROUND

Patients who experience pain, swelling, and trismus after third-molar extraction are reported to experience a 3-fold higher rate of adverse effects (AEs) on quality of life compared with those who are asymptomatic after this surgery. Therefore, investigators emphasize the necessity for better control of this triad of sequelae. Steroids can reduce the risk for physiologic processes of inflammation, thereby suppressing the development of inflammation.

OBJECTIVE

The aim of this study was to compare the effects of dexamethasone 8 mg IM and diclofenac potassium (K) 50 mg PO, dexamethasone 8 mg IM and acetaminophen 1000 mg PO, and monotherapy with diclofenac K 50 mg PO on postoperative pain, swelling, and trismus after surgical removal of third molars.

METHODS

This prospective, randomized, open-label pilot study was conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Lagos, Nigeria. Patients were randomly allocated to 1 of 3 treatment groups: concomitant treatment with dexamethasone 8 mg IM and diclofenac K 50 mg PO or acetaminophen 1000 mg PO, or monotherapy with diclofenac K 50 mg PO. Overall analgesic efficacy of the drug combinations was assessed for 7 days postoperatively using a 4-point categorical pain-intensity rating scale (0 = no pain; 1 = mild pain; 2 = moderate pain; and 3 = severe pain). Facial swelling was measured in 1 dimension on days 1, 2, and 7 after surgery using a tape measure placed from the tip of the tragus, to gonion, to the tip of the contralateral tragus, and trismus was assessed using interincisal mouth-opening ability, measured using a vernier-calibrated caliper on postoperative days 1, 2, and 7. Tolerability was assessed using direct questioning of the patients at follow-up visits.

RESULTS

A total of 150 patients (50 per treatment group) were included in the analysis (76 women, 74 men; mean [SD] age, 26.8 [5.04] years [range, 18-45 years]; 100% Nigerian). The proportion of patients reporting no pain on the pain-intensity rating scale was significantly higher in the group receiving dexamethasone and diclofenac K compared with that in the groups receiving dexamethasone and acetaminophen or diclofenac K monotherapy (44% vs 22% and 24%, respectively; both, P < 0.05). Facial swelling was significantly less with dexamethasone and diclofenac K or dexamethasone and acetaminophen compared with diclofenac K alone (day 1: P = 0.013 and P = 0.011, respectively; day 2: P = 0.002 and P = 0.004, respectively). However, trismus relief was statistically similar between the 3 treatment groups on postoperative days 1 and 2. No AEs or complications were recorded.

CONCLUSION

In this open-label pilot study, concomitant treatment with dexamethasone and diclofenac K provided significant relief of postsurgical pain and swelling compared with dexamethasone and acetaminophen or monotherapy with diclofenac K after third-molar extraction in these patients.

Effects of far-infrared irradiation on myofascial neck pain: a randomized, double-blind, placebo-controlled pilot study

OBJECTIVES

The objective of this study was to determine the relative efficacy of irradiation using a device containing a far-infrared emitting ceramic powder (cFIR) for the management of chronic myofascial neck pain compared with a control treatment.

DESIGN

This was a randomized, double-blind, placebo-controlled pilot study.

PARTICIPANTS

The study comprised 48 patients with chronic, myofascial neck pain.

INTERVENTION

Patients were randomly assigned to the experimental group or the control (sham-treatment) group. The patients in the experimental group wore a cFIR neck device for 1 week, and the control group wore an inert neck device for 1 week.

MAIN OUTCOME MEASUREMENT

Quantitative measurements based on a visual analogue scale (VAS) scoring of pain, a sleep quality assessment, pressure-pain threshold (PPT) testing, muscle tone and compliance analysis, and skin temperature analysis were obtained.

RESULTS

Both the experimental and control groups demonstrated significant improvement in pain scores. However, no statistically significant difference in the pain scores was observed between the experimental and control groups. Significant decreases in muscle stiffness in the upper regions of the trapezius muscles were reported in the experimental group after 1 week of treatment.

CONCLUSIONS

Short-term treatment using the cFIR neck device partly reduced muscle stiffness. Although the differences in the VAS and PPT scores for the experimental and control groups were not statistically significant, the improvement in muscle stiffness in the experimental group warrants further investigation of the long-term effects of cFIR treatment for pain management.

Advertisements impact the physiological efficacy of a branded drug

We conducted randomized clinical trials to examine the impact of direct-to-consumer advertisements on the efficacy of a branded drug. We compared the objectively measured, physiological effect of Claritin (Merck & Co.), a leading antihistamine medication, across subjects randomized to watch a movie spliced with advertisements for Claritin or advertisements for Zyrtec (McNeil), a competitor antihistamine. Among subjects who test negative for common allergies, exposure to Claritin advertisements rather than Zyrtec advertisements increases the efficacy of Claritin. We conclude that branded drugs can interact with exposure to television advertisements.

The effect of continuous ultrasound on chronic non-specific low back pain: a single blind placebo-controlled randomized trial

BACKGROUND

Non-specific chronic low back pain (NSCLBP) is one of the most common musculoskeletal disorders around the world including Iran. One of the most widely used modalities in the field of physiotherapy is therapeutic ultrasound (US). Despite its common use, there is still inconclusive evidence to support its effectiveness in patients with NSCLBP. The objective of this study was to evaluate the effect of continuous US compared with placebo US additional to exercise therapy for patients with NSCLBP.

METHODS

In this single blind placebo controlled study, 50 patients with NSCLBP were randomized into two treatment groups: 1) continuous US (1 MHz &1.5 W/cm2) plus exercise 2) placebo US plus exercise. Patients received treatments for 4 weeks, 10 treatment sessions, 3 times per week, every other day. Treatment effects were assessed in terms of primary outcome measures: 1) functional disability, measured by Functional Rating Index, and 2) global pain, measured by a visual analog scale. Secondary outcome measures were lumbar flexion and extension range of motion (ROM), endurance time and rate of decline in median frequency of electromyography spectrum during a Biering Sorensen test. All outcome variables were measured before, after treatment, and after one-month follow-up. An intention to treat analysis was performed. Main effects of Time and Group as well as their interaction effect on outcome measures were investigated using repeated measure ANOVA.

RESULTS

Analysis showed that both groups had improved regarding function (FRI) and global pain (VAS) (P < .001). Lumbar ROM as well as holding time during the Sorensen test and median frequency slope of all measured paravertebral muscles did not change significantly in either group (P > .05). Improvement in function and lumbar ROM as well as endurance time were significantly greater in the group receiving continuous US (P < .05).

CONCLUSIONS

The study showed that adding continuous US to a semi supervised exercise program significantly improved function, lumbar ROM and endurance time. Further studies including a third group of only exercise and no US can establish the possible effects of placebo US.

TRIAL REGISTRATION

NTR2251.

Placebo use in clinical practice by nurses in an Iranian teaching hospital

The present study was carried out to explore Iranian nurses' use of placebos in clinical practice and their knowledge and attitude towards its use. A cross-sectional, descriptive study was conducted using self-report questionnaires. All nurses working in a university hospital in Arak (n=342) were invited to participate in the study. Among 295 respondents, 221 (75%) reported that they had used at least one placebo within the past year and 179 (81%) told patients they were receiving actual medication. The most common reason and symptom for placebo use were after unjustified demand for medication and pain, respectively. Only 60 (20.33%) of the nurses believed that placebos should never be used. Results showed that most nurses in our study had used placebos and probably will continue to use them. Placebo use is viewed as ethically permissible among nurses. Some patients benefit from the placebos, but their use raises ethical questions. The role of placebo treatment, its mechanisms, and its ethics issues should be taught to nurses.

Conservative treatment of tibialis posterior tendon dysfunction--a review

BACKGROUND

Appropriate conservative treatment is considered essential to address symptoms associated with tibialis posterior tendon dysfunction (TPTD) and prevent its potential long-term disabling consequences. The main aim of this review, undertaken in 2007, was to evaluate the evidence from studies for the effects of conservative treatment modalities in the management of TPTD. This evidence could then be used as a basis for the development of a clinical guideline for the management of the condition.

METHODOLOGY

Studies were selected according to specific criteria and evaluated for methodological quality. As preliminary literature searches had identified no randomised controlled trials at the time of the review, studies of lower hierarchy were included.

RESULTS

Five uncontrolled observational studies evaluating the outcomes of various orthotic treatments alone or in combination with other therapies were included in the review. Different study designs, methodological quality, population characteristics, interventions and outcome measures were found.

DISCUSSION

Limited and poor quality evidence was found in this review regarding the conservative treatment of TPTD. Thus a cause-effect relationship between intervention and outcome could not be established nor an optimal conservative treatment regime for the condition. Further better quality research is warranted in this area to inform practice, particularly as there is no consensus in the literature regarding treatment of this condition.

Placebo interventions for all clinical conditions

BACKGROUND

Placebo interventions are often claimed to substantially improve patient-reported and observer-reported outcomes in many clinical conditions, but most reports on effects of placebos are based on studies that have not randomised patients to placebo or no treatment. Two previous versions of this review from 2001 and 2004 found that placebo interventions in general did not have clinically important effects, but that there were possible beneficial effects on patient-reported outcomes, especially pain. Since then several relevant trials have been published.

OBJECTIVES

Our primary aims were to assess the effect of placebo interventions in general across all clinical conditions, and to investigate the effects of placebo interventions on specific clinical conditions. Our secondary aims were to assess whether the effect of placebo treatments differed for patient-reported and observer-reported outcomes, and to explore other reasons for variations in effect.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 4, 2007), MEDLINE (1966 to March 2008), EMBASE (1980 to March 2008), PsycINFO (1887 to March 2008) and Biological Abstracts (1986 to March 2008). We contacted experts on placebo research, and read references in the included trials.

SELECTION CRITERIA

We included randomised placebo trials with a no-treatment control group investigating any health problem.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. Trials with binary data were summarised using relative risk (a value of less than 1 indicates a beneficial effect of placebo), and trials with continuous outcomes were summarised using standardised mean difference (a negative value indicates a beneficial effect of placebo).

MAIN RESULTS

Outcome data were available in 202 out of 234 included trials, investigating 60 clinical conditions. We regarded the risk of bias as low in only 16 trials (8%), five of which had binary outcomes.In 44 studies with binary outcomes (6041 patients), there was moderate heterogeneity (P < 0.001; I(2) 45%) but no clear difference in effects between small and large trials (symmetrical funnel plot). The overall pooled effect of placebo was a relative risk of 0.93 (95% confidence interval (CI) 0.88 to 0.99). The pooled relative risk for patient-reported outcomes was 0.93 (95% CI 0.86 to 1.00) and for observer-reported outcomes 0.93 (95% CI 0.85 to 1.02). We found no statistically significant effect of placebo interventions in four clinical conditions that had been investigated in three trials or more: pain, nausea, smoking, and depression, but confidence intervals were wide. The effect on pain varied considerably, even among trials with low risk of bias.In 158 trials with continuous outcomes (10,525 patients), there was moderate heterogeneity (P < 0.001; I(2) 42%), and considerable variation in effects between small and large trials (asymmetrical funnel plot). It is therefore a questionable procedure to pool all the trials, and we did so mainly as a basis for exploring causes for heterogeneity. We found an overall effect of placebo treatments, standardised mean difference (SMD) -0.23 (95% CI -0.28 to -0.17). The SMD for patient-reported outcomes was -0.26 (95% CI -0.32 to -0.19), and for observer-reported outcomes, SMD -0.13 (95% CI -0.24 to -0.02). We found an effect on pain, SMD -0.28 (95% CI -0.36 to -0.19)); nausea, SMD -0.25 (-0.46 to -0.04)), asthma (-0.35 (-0.70 to -0.01)), and phobia (SMD -0.63 (95% CI -1.17 to -0.08)). The effect on pain was very variable, also among trials with low risk of bias. Four similarly-designed acupuncture trials conducted by an overlapping group of authors reported large effects (SMD -0.68 (-0.85 to -0.50)) whereas three other pain trials reported low or no effect (SMD -0.13 (-0.28 to 0.03)). The pooled effect on nausea was small, but consistent. The effects on phobia and asthma were very uncertain due to high risk of bias. There was no statistically significant effect of placebo interventions in the seven other clinical conditions investigated in three trials or more: smoking, dementia, depression, obesity, hypertension, insomnia and anxiety, but confidence intervals were wide.Meta-regression analyses showed that larger effects of placebo interventions were associated with physical placebo interventions (e.g. sham acupuncture), patient-involved outcomes (patient-reported outcomes and observer-reported outcomes involving patient cooperation), small trials, and trials with the explicit purpose of studying placebo. Larger effects of placebo were also found in trials that did not inform patients about the possible placebo intervention.

AUTHORS' CONCLUSIONS

We did not find that placebo interventions have important clinical effects in general. However, in certain settings placebo interventions can influence patient-reported outcomes, especially pain and nausea, though it is difficult to distinguish patient-reported effects of placebo from biased reporting. The effect on pain varied, even among trials with low risk of bias, from negligible to clinically important. Variations in the effect of placebo were partly explained by variations in how trials were conducted and how patients were informed.

Placebo effects: clinical aspects and neurobiology

Placebo effects are beneficial health outcomes not related to the relatively direct biological effects of an intervention and can be elicited by an agent that, by itself, is inert. Understanding these placebo effects will help to improve clinical trial design, especially for interventions such as surgery, CNS-active drugs and behavioural interventions which are often non-blinded. A literature review was performed to retrieve articles discussing placebo implications of clinical trials, the neurobiology of placebo effects and the implications of placebo effect for several disorders of neurological relevance. Recent research in placebo analgesia and other conditions has demonstrated that several neurotransmitter systems, such as opiate and dopamine, are involved with the placebo effect. Brain regions including anterior cingulate cortex, dorsolateral prefrontal cortex and basal ganglia have been activated following administration of placebo. A patient's expectancy of improvement may influence outcomes as much as some active interventions and this effect may be greater for novel interventions and for procedures. Maximizing this expectancy effect is important for clinicians to optimize the health of their patient. There have been many relatively acute placebo studies that are now being extended into clinically relevant models of placebo effect.

Ultrasound in contemporary physiotherapy practice

The use of therapeutic ultrasound as an element of physiotherapy practice is well established, but the nature of that practice has changed significantly over the last 20 years. This paper aims to review the rationale and range of applications for which this modality is employed in current practice. Whereas in the past, its primary use was as a thermal modality, it is argued that currently, it is the 'non-thermal' aspects of the intervention that are most commonly employed. The predominant use of therapeutic ultrasound is in relation to tissue repair and soft tissue lesion management, where the evidence would support its application in the inflammatory, proliferative and remodelling phases. The clinical outcomes appear to be dose dependent, and whilst this paper does not detail dose related clinical decision making, the broad issues are considered. The future possibilities for the use of the modality are reviewed, and although outside the immediate remit of this paper, the use of therapeutic ultrasound in fracture management is briefly considered.

Peripheral therapeutic ultrasound stimulation alters the distribution of spinal C-fos immunoreactivity induced by early or late phase of inflammation

The purpose of this investigation was to examine the central modulated effects of therapeutic ultrasound (US) on neuronal activity in the spinal cord on early and late phases of inflammation. In this study, induction of c-Fos protein, which reflects neuronal activation (particularly inflammatory nociception), was investigated in the lumbar spinal cord with immunohistochemistry. Inflammatory monoarthritis was induced in 20 male Wistar rats (weighing 250-300 g) via intra-articular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. Two phases of arthritis, early phase (18 h after adjuvant injection) and late phase (7 d after adjuvant injection), were studied in the rats. Pulsed-mode US (1 MHz, the spatial average temporal average intensity [I(SATA)] = 0.5 W/cm(2), 50% duty cycle) was applied for 5 min. The effects of US and sham treatments against these phases of arthritis were demonstrated by spinal c-Fos-like immunoreactivity (c-Fos-LI). All data were evaluated statistically with the paired t-test or analysis of variance with Bonferroni corrections. c-Fos-LI neurons were abundant (average 264.2 +/- 11.9) in the L3 and L4 neurons of the spinal cord in areas ipsilateral to the CFA-induced arthritic leg in the early phase, but few were present (average 40.4 +/- 4.5) in the late phase in sham-treated animals. Bonferroni corrections to the alpha level were used to check the group differences in spinal c-Fos expression, and significance was reached when p < 0.025. In the early inflammatory phase, US treatment significantly suppressed the increased number of c-Fos-LI neurons associated with CFA-induced arthritis in superficial laminae, nucleus proprius, deep laminae and ventral horn of the spinal cord. However, during the late inflammatory phase, US significantly triggered c-Fos expression in most laminae, particularly in the nucleus proprius, deep laminae and ventral horn of the spinal cord. The results of our study suggest that administration of US causes a reduction of early nociceptive inflammatory processing, as shown by a decrease in CFA-induced c-Fos-LI neurons at the level of the spinal cord. In contrast, the US did not suppress, but rather enhanced, the number of c-Fos-LI neurons during the late inflammatory phase. The peripheral influences of US on the central modulation of the spinal nociceptive processing system is suggested and may reflect the work being done through the neuroplasticity of spinal cord in response to peripheral stimulation of US. Therefore, we propose a difference in spinal expression of c-Fos-LI neurons between effects of peripheral US stimulation in arthritic models that underlie early and late inflammatory pain. (E-mail: sherrie@sunrise.hk.edu.tw).

Computerized tomography evaluation of cortical bone properties in the tibia

BACKGROUND

Tibia shaft fractures are among the most common fractures. However, the incidence of tibia fractures does not increase in the elderly. Osteoporotic bone resorption is possibly compensated for by periosteal apposition, which improves the mechanical properties of the bone. The purpose of this study was to identify a correlation between geometric indices of transverse bone scans and radiologic bone density based in CT studies.

MATERIAL AND METHODS

12 human cadaver tibiae were CT examined. Radiological density in Hounsfield units was evaluated in transverse bone scans taken at the junction of the distal and middle third of the tibial shaft. The average and maximum radiological density and area of cortical bone were evaluated.

RESULTS

Average radiological bone density decreased with age. This was not accompanied by a corresponding increase in cortical bone area.

CONCLUSION

The study did not provide direct confirmation that age-related osteoporotic bone resorption is compensated for by periosteal apposition.

Evidence for placebo effects on physical but not on biochemical outcome parameters: a review of clinical trials

BACKGROUND

Recent reviews on placebo effects in clinical trials suggest that objective changes following placebo treatments may not exist or, at least, have been considerably overestimated. However, the possibility that yet unidentified subsets of parameters are responsive to placebo treatments has not been taken into account. Therefore, the aim of the present study is to examine the effects of placebo treatments on objectively measured outcome parameters by specifically focusing on peripheral disease processes.

METHODS

An initial dataset was collected from a MEDLINE search for placebo-controlled, randomized clinical trials. Trials with stable disease conditions were identified, and the effects of placebo treatments on peripheral outcome parameters were estimated by the changes from baseline in the placebo groups. An explorative data analysis was conducted in order to identify parameter classes with differential responsiveness to placebo treatments. A subgroup meta-analysis of a second dataset was performed to test whether the preliminary classification would also apply to placebo effects derived from the comparison of placebo groups with untreated control groups.

RESULTS

The explorative analysis of outcome parameters and strength of placebo effects yielded a classification into responsive "physical" versus non-responsive "biochemical" parameters. In total, 50% of trials measuring physical parameters showed significant placebo effects, compared with 6% of trials measuring biochemical parameters. A subgroup meta-analysis substantiated the differential response (physical parameters: n = 14, Hedges' pooled effect size g = 0.34, 95% CI 0.22 to 0.46; biochemical parameters: n = 15, g = 0.03, 95% CI -0.04 to 0.10). The subanalysis of the second dataset supported the classification and revealed a significant improvement for physical parameters (n = 20, g = 0.22, 95% CI 0.07 to 0.36) and a deterioration for biochemical parameters (n = 6, g = -0.17, 95% CI -0.31 to -0.02).

CONCLUSION

The results suggest that placebo interventions can improve physical disease processes of peripheral organs more easily and effectively than biochemical processes. This differential response offers a good starting point for theoretical considerations on possible mediating mechanisms, and for future investigations in this field.

Classical conditioning and expectancy in placebo hypoalgesia: a randomized controlled study in patients with atopic dermatitis and persons with healthy skin

The effectiveness of placebos is unchallenged. However, it is still not clear on which mechanisms the placebo effect is based. Besides expectancy theories, classical conditioning is discussed as a major explanatory model. In an experimental conditioning design we tested 96 participants, 48 with atopic dermatitis (24 male, 24 female) and 48 with healthy skin (24 male and 24 female). All of them received a neutral ointment with a different briefing ("pain-reducing ointment" versus "neutral ointment"). Electrical pain stimuli were subsequently applied, which selectively induce a painful sensation. In the case of the learning condition (classical conditioning) and unbeknown to the participants, the intensity of the pain stimulus was reduced by 50% after the ointment had been applied. The study addressed the question whether the pain experienced by the patients with atopic dermatitis could be reduced through a placebo effect and whether the placebo effect was achieved through expectancy or through a process of classical conditioning or both. The results indicate that a placebo effect is achieved via expectancy and classical conditioning. However, conditioning processes seem to be necessary for a longer lasting effect. The extent of this effect seemed to be greater in atopics than in healthy controls. Expectancy, achieved through verbal instruction, might also be seen as a conditioned stimulus that reactivates earlier stimulus associations.

Expectations and associations that heal: Immunomodulatory placebo effects and its neurobiology

The use of placebo may have accompanied healing and medical practices since their origins (Plato; Charmides, 155-156). Recent experimental data indicate that we would be well advised to further consider placebo effects in future therapeutic strategies, with a better knowledge of their potency, psychological basis and underlying neurobiological mechanisms. Current research in the areas of pain, depression and Parkinson's disease has uncovered some of the potential neurobiological mechanisms of placebo effects. These data indicate that conscious expectation and unconscious behavioral conditioning processes appear to be the major neurobiological mechanisms capable of releasing endogenous neurotransmitters and/or neurohormones that mimic the expected or conditioned pharmacological effects. To date, research on placebo responses affecting immune-related diseases is scarce, but there are consistent indications that skin and mucosal inflammatory diseases, in particular, are strongly modulated by placebo treatments. However, the brain's capability to modulate peripheral immune reactivity has been impressively demonstrated by paradigms of behavioral conditioning in animal experiments and human studies. Thus, placebo effects can benefit end organ functioning and the overall health of the individual through positive expectations and behavioral conditioning processes.

Physical agents used in the management of chronic pain by physical therapists

Evidence supporting the use of specific physical agents in the management of chronic pain conditions is not definitive; it is largely incomplete and sometimes contradictory. However, the use of agents in chronic pain management programs is common. Within the broad use of physical agents, they are rarely the sole modality of treatment. A 1995 American Physical Therapy Association position statement asserts that "Without documentation which justifies the necessity of the exclusive use of physical agents/modalities, the use of physical agents/modalities, in the absence of other skilled therapeutic or educational intervention, should not be considered physical therapy". Physical agents may serve as useful adjunctive modalities of pain relief or to enhance the effectiveness of other elements in therapy geared toward resolution of movement impairments and restoration of physical function. Given that a conclusive aggregate of findings is unlikely to exist for all permutations of patient conditions, combined with interacting therapeutic modalities, an evidence-based approach to pain management is not always possible or beneficial to the patient. In the face of inconclusive evidence, a theory-based approach may help determine if the therapeutic effect ofa given physical agent has the possibility of being a useful clinical tool in the context of treating a particular patient's mechanism of pain generation. Until controlled efficacy findings are definitive, careful individual patient response monitoring of thoughtful theoretical application of adjunctive physical agents may be a prudent approach to the management of chronic pain.

The changing role of non-opioid analgesic techniques in the management of postoperative pain

Given the expanding role of ambulatory surgery and the need to facilitate an earlier hospital discharge, improving postoperative pain control has become an increasingly important issue for all anesthesiologists. As a result of the shift from inpatient to outpatient surgery, the use of IV patient-controlled analgesia and continuous epidural infusions has steadily declined. To manage the pain associated with increasingly complex surgical procedures on an ambulatory or short-stay basis, anesthesiologists and surgeons should prescribe multimodal analgesic regimens that use non-opioid analgesics (e.g., local anesthetics, nonsteroidal antiinflammatory drugs, cyclooxygenase inhibitors, acetaminophen, ketamine, alpha 2-agonists) to supplement opioid analgesics. The opioid-sparing effects of these compounds may lead to reduced nausea, vomiting, constipation, urinary retention, respiratory depression and sedation. Therefore, use of non-opioid analgesic techniques can lead to an improved quality of recovery for surgical patients.

Suppression of the acute-phase response as a biological mechanism for the placebo effect

The idea that inert substances such as sugar pills can have powerful therapeutic effects--the so-called 'placebo effect'--has been widely accepted by most medical researchers since the 1950s. Today there is increasing scepticism about the reality of the placebo effect. This debate has been too simplistic; rather than asking whether or not the placebo effect exists, as researchers have done up to now, we should be more precise, and ask which medical conditions (if any) are placebo-responsive. There is evidence that pain, swelling, stomach ulcers, depression, and anxiety are all placebo-responsive. These conditions have all been linked, to a greater or lesser extent, with activation of the acute-phase response (the innate immune response). The placebo effect may therefore be mediated by alteration of one or more components of the acute-phase response. The candidates for such biochemical mediators would need to alter the synthesis, activation, receptor-binding or signalling mechanisms of inflammation, sickness behaviour and other aspects of innate immunity. This hypothesis is consistent with current data suggesting that placebos work by triggering the release of endorphins. The hypothesis would be falsified if it were found that other medical conditions, not involving the activation of the acute-phase response, were nonetheless alleviated by placebos.

Placebo interventions for all clinical conditions

BACKGROUND

Placebo interventions are often claimed to improve patient-reported and observer-reported outcomes, but this belief is not based on evidence from randomised trials that compare placebo with no treatment.

OBJECTIVES

To assess the effect of placebo interventions.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2002), MEDLINE (1966 to 2002), EMBASE (1980 to 2002), Biological Abstracts (1986 to 2002), and PsycLIT (1887 to 2002). We contacted experts on placebo research, and read references in the included trials.

SELECTION CRITERIA

We included randomised placebo trials with a no-treatment control group investigating any health problem.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Outcome data were available in 156 out of 182 included trials, investigating 46 clinical conditions. We found no statistically significant pooled effect of placebo in 38 studies with binary outcomes (4284 patients), relative risk 0.95 (95% confidence interval (CI) 0.89 to 1.01). The pooled relative risk for patient-reported outcomes was 0.95 (95% CI 0.88 to 1.03) and for observer-reported outcomes 0.91 (95% CI 0.81 to 1.03). There was heterogeneity (P=0.01) but the funnel plot was symmetrical. There was no statistically significant effect of placebo interventions in the four clinical conditions investigated in three trials or more: pain, nausea, smoking, and depression, but confidence intervals were wide. We found an overall effect of placebo treatments in 118 trials with continuous outcomes (7453 patients), standardised mean difference (SMD) -0.24 (95% CI -0.31 to -0.17). The SMD for patient-reported outcomes was -0.30 (95% CI -0.38 to -0.21), whereas no statistically significant effect was found for observer-reported outcomes, SMD -0.10 (95% CI -0.20 to -0.01). There was heterogeneity (P<0.001) and large variability in funnel plot results even for big trials. There was an apparent effect of placebo interventions on pain (SMD -0.25 (95% CI -0.35 to-0.16)), and phobia (SMD -0.63 (95% CI -1.17 to -0.08)); but also a substantial risk of bias. There was no statistically significant effect of placebo interventions in eight other clinical conditions investigated in three trials or more: nausea, smoking, depression, overweight, asthma, hypertension, insomnia and anxiety, but confidence intervals were wide.

REVIEWERS' CONCLUSIONS

There was no evidence that placebo interventions in general have clinically important effects. A possible small effect on continuous patient-reported outcomes, especially pain, could not be clearly distinguished from bias.

Placebo treatment versus no treatment

BACKGROUND

Placebo interventions are often believed to improve patient reported and observer reported outcomes, but this belief is not based on evidence from randomised trials that compare placebo with no treatment.

OBJECTIVES

To assess the effect of placebo interventions.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (The Cochrane Library, issue 3, 1998), MEDLINE (Jan 1966 to Dec 1998), EMBASE (Jan 1980 to Dec 1998), Biological Abstracts (Jan 1986 to Dec 1998), PsycLIT (Jan 1887 to Dec 1998). Experts on placebo research were contacted and references in the included trials were read.

SELECTION CRITERIA

Randomised placebo trials with a no-treatment control group investigating any health problem were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Outcome data were available in 114 out of 130 included trials, investigating 40 clinical conditions. Outcomes were binary in 32 trials (3795 patients) and continuous in 82 (4730 patients). We found no statistically significant pooled effect of placebo in studies with binary outcomes, relative risk 0.95 (95 per cent confidence interval 0.88 to 1.02). The pooled relative risk for subjective (patient reported) outcomes was 0.95 (0.86 to 1.05) and for objective (observer reported) outcomes 0.91 (0.80 to 1.04). There was statistically significant heterogeneity (P < 0.03), but no evidence of sample size bias (P = 0.56). We found an overall positive effect of placebo treatments in trials with continuous outcomes, standardised mean difference -0.28 (95 per cent confidence interval -0.38 to -0.19). The standardised mean difference for subjective outcomes was -0.36 (-0.47 to -0.25), whereas no statistically significant effect was found for objective outcomes, standardised mean difference -0.12 (-0.27 to 0.03). There was statistically significant heterogeneity (P < 0.001), and evidence of sample size bias (P = 0.05). There was no statistically significant effect of placebo interventions in eight out of nine clinical conditions investigated in three trials or more (nausea, relapse in prevention of smoking and depression, overweight, asthma, hypertension, insomnia and anxiety), but confidence intervals were wide. There was a modest apparent analgesic effect of placebo interventions, standardised mean difference -0.27 (-0.40 to -0.15), but also a substantial risk of bias.

REVIEWER'S CONCLUSIONS

There was no evidence that placebo interventions in general have clinically important effects. A possible moderate effect on subjective continuous outcomes, especially pain, could not be clearly distinguished from bias.

A comparison of placebo effects in clinical analgesic trials versus studies of placebo analgesia

A previous meta-analysis of clinical analgesic trial studies showed generally low magnitudes of placebo analgesia (N. Engl. J. Med. 344 (2001) 1594). However, as studies included in their analysis used only placebo as a control condition, we conducted two meta-analyses, one in which 23 studies used only placebo as a control condition, and one in which 14 studies investigated placebo analgesic mechanisms. Magnitudes of placebo analgesic effects were much higher in the latter (mean effect size=0.95) as compared to the former (mean effect size=0.15) and were significantly different (P=0.003). This difference as well as differences in effect sizes within studies of placebo mechanisms may be parsimoniously explained by differences in expected pain levels produced by placebo suggestions and by conditioning. Furthermore, some of the studies of placebo analgesic mechanisms indicate that the magnitude of placebo analgesia is higher when the placebo analgesic effect is induced via suggestion combined with conditioning than via suggestion alone or conditioning alone. Based on these findings, we suggest that placebo analgesic effects are most optimally conceptualized in terms of perception of the placebo agent, and therefore a new definition of placebo response is proposed.

A Review of Therapeutic Ultrasound: Biophysical Effects

Almost 2 decades ago, it was pointed out that physical therapists tended to overlook the tenuous nature of the scientific basis for the use of therapeutic ultrasound. The purpose of this review is to examine the literature regarding the biophysical effects of therapeutic ultrasound to determine whether these effects may be considered sufficient to provide a reason (biological rationale) for the use of insonation for the treatment of people with pain and soft tissue injury. This review does not discuss articles that examined the clinical usefulness of ultrasound (see article by Robertson and Baker titled “A Review of Therapeutic Ultrasound: Effectiveness Studies” in this issue). The frequently described biophysical effects of ultrasound either do not occur in vivo under therapeutic conditions or have not been proven to have a clinical effect under these conditions. This review reveals that there is currently insufficient biophysical evidence to provide a scientific foundation for the clinical use of therapeutic ultrasound for the treatment of people with pain and soft tissue injury.

Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment

BACKGROUND

Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated.

METHODS

We conducted a systematic review of clinical trials in which patients were randomly assigned to either placebo or no treatment. A placebo could be pharmacologic (e.g., a tablet), physical (e.g., a manipulation), or psychological (e.g., a conversation).

RESULTS

We identified 130 trials that met our inclusion criteria. After the exclusion of 16 trials without relevant data on outcomes, there were 32 with binary outcomes (involving 3795 patients, with a median of 51 patients per trial) and 82 with continuous outcomes (involving 4730 patients, with a median of 27 patients per trial). As compared with no treatment, placebo had no significant effect on binary outcomes (pooled relative risk of an unwanted outcome with placebo, 0.95; 95 percent confidence interval, 0.88 to 1.02), regardless of whether these outcomes were subjective or objective. For the trials with continuous outcomes, placebo had a beneficial effect (pooled standardized mean difference in the value for an unwanted outcome between the placebo and untreated groups, -0.28; 95 percent confidence interval, -0.38 to -0.19), but the effect decreased with increasing sample size, indicating a possible bias related to the effects of small trials. The pooled standardized mean difference was significant for the trials with subjective outcomes (-0.36; 95 percent confidence interval, -0.47 to -0.25) but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect (-0.27; 95 percent confidence interval, -0.40 to -0.15). This corresponded to a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale.

CONCLUSIONS

We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.