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Journal of Clinical Epidemiology Apr 2006Progress in understanding the placebo effect and its clinical significance depends on conceptual clarification of this elusive phenomenon and critical appraisal of... (Review)
Review
Progress in understanding the placebo effect and its clinical significance depends on conceptual clarification of this elusive phenomenon and critical appraisal of research bearing on the influence of placebo interventions on clinical outcomes. Here we locate the placebo effect within a typology of modes of healing, distinguish between the observed placebo response in randomized controlled trials and the placebo effect, and examine critically a recent meta-analysis of clinical trials that challenges the reality of the placebo effect.
Topics: Analgesia; Double-Blind Method; Humans; Placebo Effect; Placebos; Randomized Controlled Trials as Topic
PubMed: 16549251
DOI: 10.1016/j.jclinepi.2005.12.001 -
BioMed Research International 2016Placebo is a form of simulated medical treatment intended to deceive the patient/subject who believes that he/she received an active therapy. In clinical medicine, the... (Review)
Review
Placebo is a form of simulated medical treatment intended to deceive the patient/subject who believes that he/she received an active therapy. In clinical medicine, the use of placebo is allowed in particular circumstances to assure a patient that he is taken care of and that he/she receives an active drug, even if this is not the case. In clinical research placebo is widely used, as it allows a baseline comparison for the active intervention. If the use of placebo is highly regulated in pharmacological trials, surgery studies have a series of particularities that make its use extremely problematic and regarded less favorably. The purpose of this paper is to present three famous cases of placebo use in surgical trials and to perform an ethical analysis of their acceptability using the Declaration of Helsinki as a main regulatory source.
Topics: Biomedical Research; Humans; Placebos; Risk Assessment; Surgical Procedures, Operative
PubMed: 27595098
DOI: 10.1155/2016/2627181 -
Handbook of Clinical Neurology 2016Placebo therapy can produce meaningful, clinical relief for a variety of conditions. While placebos are not without their ethically fraught history, they continue to be... (Review)
Review
Placebo therapy can produce meaningful, clinical relief for a variety of conditions. While placebos are not without their ethically fraught history, they continue to be used, largely covertly, even today. Because the prognosis for psychogenic disorders is often poor and recovery may be highly dependent on the patient's belief in the diagnosis and treatment regimen, some physicians find placebo therapy for psychogenic disorders compelling, but also particularly contentious. Yet placebos also have a long tradition of being used for provocative diagnosis (wherein placebo is used to elicit and/or terminate the symptoms as a way of diagnosing symptoms as "psychogenic"). In this chapter we discuss cases describing placebo as therapy for psychogenic disorders and the challenges related to embedded Cartesian beliefs in Western medicine. The legitimate ethical reservations against placebo therapy, in general, have been related to assumptions about their "inertness" and a requirement for deception, both which are being refuted by emerging data. In this chapter, we also re-evaluate the concerns associated with placebo therapy for psychogenic disorders by asking, "Are we harming patients by withholding placebo treatment?"
Topics: Conversion Disorder; Humans; Nervous System Diseases; Placebos; Psychophysiologic Disorders
PubMed: 27719875
DOI: 10.1016/B978-0-12-801772-2.00049-7 -
Digestive Diseases (Basel, Switzerland) 1994Placebo, defined as any therapeutic procedure, without any specific activity, given deliberately to have an effect on a patient, symptom, syndrome or disease, has a... (Review)
Review
Placebo, defined as any therapeutic procedure, without any specific activity, given deliberately to have an effect on a patient, symptom, syndrome or disease, has a great impact in the evaluation of drug response. The possible pathways via which the possible effect brings about clinical and physiological changes remain unknown, but a humoral mechanism seems to be implicated in some placebo effects (e.g. placebo-induced analgesia). The placebo effect depends on many factors, including the type of patient, the personality of the physician, the doctor-patient relationship and the type and even the colour of the drug preparation. Placebo control is important particularly when the disease is characterized by frequent spontaneous periods of acute exacerbation and remission. Functional (such as dyspepsia and irritable bowel syndrome) and organic (such as peptic ulcer and inflammatory bowel disease) gastrointestinal diseases have got great benefit from placebo-controlled clinical trials. In such trials the more effective the placebo is, the more difficult it will be to demonstrate the efficacy of active drug in statistical terms. Nevertheless, provided the use of placebo be ethical for a given condition, placebo-controlled trials are the only objective way of assessing correctly drug response in patients.
Topics: Drug Evaluation; Humans; Placebo Effect; Placebos; Randomized Controlled Trials as Topic
PubMed: 7712618
DOI: 10.1159/000171471 -
International Review of Neurobiology 2020Throughout the history of medicine, multiple conceptions of "placebo" and "placebo effect" have often co-existed across different domains, and today the meaning of these... (Review)
Review
Throughout the history of medicine, multiple conceptions of "placebo" and "placebo effect" have often co-existed across different domains, and today the meaning of these concepts is still disputed. Against this background, this chapter provides a succinct account of the key events in the history of the concepts of "placebo," "placebo control," and "placebo effect." The first section reconstructs the etymology of the term "placebo" and its first introduction in medicine. The next sections provide an account of how placebos have been employed in both medical practice and scientific research in modern medicine. Later sections trace the emergence of the concepts of "placebo control" and "placebo effect" in the first half of the 20th century, from the first empirical studies investigating the effects of placebos up to the publication of Beecher's landmark article "The Powerful Placebo." Finally, the last two sections review the varieties of randomized, placebo-controlled trials (RCTs) in the second half of the 20th century, and the subsequent wave of empirical studies that, starting from the 1970s, have investigated the psychological, pharmacological and neurobiological mechanisms of placebo effects.
Topics: Biomedical Research; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; Humans; Placebo Effect; Placebos; Randomized Controlled Trials as Topic
PubMed: 32563292
DOI: 10.1016/bs.irn.2020.03.028 -
Lancet (London, England)
Topics: History, 18th Century; History, 19th Century; History, 20th Century; Humans; Placebo Effect; Placebos
PubMed: 15781087
DOI: 10.1016/S0140-6736(05)71124-7 -
Annales Pharmaceutiques Francaises Nov 2015After starting with a brief historical account of the placebo effect organized around the elaboration of clinical trials and around sham therapy as a method, we will... (Review)
Review
After starting with a brief historical account of the placebo effect organized around the elaboration of clinical trials and around sham therapy as a method, we will offer a psychosocial point of view on the placebo phenomenon. The placebo effect is at the heart of medicine and particularly of therapeutic trials from theoretical research on a drug to its acceptance and its use in every-day clinical practice. The placebo effect intermingles biology, relationships and the context of therapeutic interactions. This type of phenomenon originates as much from biology as from human psychology. Our article puts more precisely into question the part that psychology has in the placebo phenomenon and suggests a chart to address it. This chart refers both to the pharmacodynamic effect given to drugs in a subjective way, and to the collective representations and social interactions depending on them. What can we say about the psychosociological dimensions of the placebo effect? How is it possible to organize the scope of these dimensions to base systematic studies on them in the field of clinical trials? We try to give elements of response to these questions by suggesting the study of the placebo effect as an original field of study by necessarily mobilizing both health sciences and the human and social sciences.
Topics: Humans; Placebo Effect; Placebos; Psychology, Social
PubMed: 26044499
DOI: 10.1016/j.pharma.2015.04.006 -
Annals of the Rheumatic Diseases Dec 2008To examine the placebo effect and its potential determinants in the treatment of osteoarthritis (OA) via a systematic literature search of Medline, EMBASE, Scientific... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To examine the placebo effect and its potential determinants in the treatment of osteoarthritis (OA) via a systematic literature search of Medline, EMBASE, Scientific Citation Index, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library.
METHODS
Randomised placebo controlled trials in OA were included. The placebo effect was defined as the overall change from baseline in the placebo group. It was estimated as the effect size (ES; the standard mean difference between baseline and endpoint) and this was compared with the ES obtained from untreated control. ES for pain was the primary outcome. Statistical pooling was undertaken as appropriate and 95% CIs were used for comparison. Quality of trials was assessed and potential determinants of placebo effect were examined using multiple regression analysis. The partial regression coefficient (beta) was used to present the adjusted size of the association.
RESULTS
We identified 198 trials with 193 placebo groups (16 364 patients) and 14 untreated control groups (1167 patients) that met our inclusion criteria. These included a range of therapies (non-pharmacological, pharmacological and surgical treatments). Placebo was effective at relieving pain (ES 0.51, 95% CI 0.46 to 0.55 for the placebo group and 0.03, 95% CI -0.13 to 0.18 for untreated control). Placebo was also effective at improving function and stiffness. The pain-relieving effect increased when the active treatment effect (beta=0.38, p<0.001), baseline pain (0.006, p=0.014) and sample size (0.001, p=0.004) increased, and when placebo was given through injections/needles (0.144, p=0.020).
CONCLUSION
Placebo is effective in the treatment of OA, especially for pain, stiffness and self-reported function. The size of this effect is influenced by the strength of the active treatment, the baseline disease severity, the route of delivery and the sample size of the study.
Topics: Aged; Female; Humans; Injections, Intra-Articular; Male; Middle Aged; Osteoarthritis; Pain Measurement; Placebo Effect; Placebos; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 18541604
DOI: 10.1136/ard.2008.092015 -
Palliative Medicine Sep 1997
Review
Topics: Controlled Clinical Trials as Topic; Ethics, Medical; Humans; Palliative Care; Placebo Effect; Placebos; Randomized Controlled Trials as Topic; Research
PubMed: 9472601
DOI: 10.1177/026921639701100514 -
Arzneimittel-Forschung May 1999The therapeutic efficacy of placebo in a series of diseases has long been known. It is less well known, however, that treatment with placebo can also produce significant... (Review)
Review
UNLABELLED
The therapeutic efficacy of placebo in a series of diseases has long been known. It is less well known, however, that treatment with placebo can also produce significant adverse drug reactions. Therefore, the placebo drug reactions from controlled trials were studied for the first time systematically.
METHOD
The efficacy and the safety of placebos were investigated using patient and drug data pooled from randomized, placebo-controlled, multicentre studies in five different groups of indications covering the therapeutic areas of cardiology (nisoldipine), neurology/psychiatry (nimodipine/ipsapirone), metabolism (acarbose) and gastroenterology (hydrotalcite).
RESULTS
The efficacy of placebo was clear, and varied not only between the five indication groups but also within them. Whereas placebo, unlike active treatment, produced hardly any improvement in symptoms in patients with severe stroke, it was as effective as active treatment in patients with mild neurological deficits, producing an improvement of about 50%. In patients with angina pectoris, placebo produced an increase in exercise tolerance (treadmill walking time to onset of ST-segment depression and angina attacks) of about 10% on average, compared with about 22% under active treatment (nisoldipine). In diabetes therapy, placebo produced no improvement in fasting and postprandial blood glucose levels compared with active treatment (acarbose), and also had no effect on HbA1C values. ADVERSE EFFECTS OF PLACEBO: Adverse drug reactions were observed under treatment with placebo. The frequency and type of placebo-induced adverse reactions also varied between indication groups. For example, typical cardiovascular effects such as tachycardia were observed in the control group. The placebo side effect profile was largely similar to the side effect profile of the active treatment. Some adverse drug reactions (such as "dry mouth" in patients with generalized anxiety syndromes) were observed more frequently under placebo than under active treatment.
CONCLUSIONS
Treatment with placebo is frequently effective and cannot therefore be considered as "non-treatment". Placebo effects can only be quantified by direct comparison with "non-treatment". Like active treatment, treatment with placebo is frequently accompanied by adverse drug reactions. Placebo adverse effects are often disease- and active treatment-specific. The effects and adverse effects of a placebo need to be known before the effects of active treatment in controlled clinical trials can be assessed. The mechanisms of placebo effects are many and varied (e.g. endorphin release, conditioning). Since the use of drugs without regard to evidence-based medicine (prescription of drugs without proven efficacy = pseudoplacebos) may clearly also result in serious adverse effects, such practice may not only be non-beneficial but may even be harmful.
Topics: Controlled Clinical Trials as Topic; Humans; Placebo Effect; Placebos; Randomized Controlled Trials as Topic; Research Design
PubMed: 10367099
DOI: 10.1055/s-0031-1300432