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Research papers on The placebo effect

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  1. Risks and Benefits of Estrogen Plus Progestin in Healthy Postmenopausal Women: Principal Results From the Women's Health Initiative Randomized Controlled Trial

    Writing Group for the Women's Health Initiative Investigators · 2002 · JAMA · 15,859 citations

    CONTEXT: Despite decades of accumulated observational evidence, the balance of risks and benefits for hormone use in healthy postmenopausal women remains uncertain. OBJECTIVE: To assess the major health benefits and risks of the most commonly used combined hormone preparation in the United States. DESIGN: Estrogen plus progestin component of the Women's Health Initiative, a randomized controlled primary prevention trial (planned duration, 8.5 years) in which 16608 postmenopausal women aged 50-79 years with an intact uterus at baseline were recruited by 40 US clinical centers in 1993-1998. INTERVENTIONS: Participants received conjugated equine estrogens, 0.625 mg/d, plus medroxyprogesterone a

  2. The Effect of Spironolactone on Morbidity and Mortality in Patients with Severe Heart Failure

    Bertram Pitt, Faı̈ez Zannad, Willem J. Remme, et al. · 1999 · New England Journal of Medicine · 9,127 citations

    BACKGROUND AND METHODS: Aldosterone is important in the pathophysiology of heart failure. In a doubleblind study, we enrolled 1663 patients who had severe heart failure and a left ventricular ejection fraction of no more than 35 percent and who were being treated with an angiotensin-converting-enzyme inhibitor, a loop diuretic, and in most cases digoxin. A total of 822 patients were randomly assigned to receive 25 mg of spironolactone daily, and 841 to receive placebo. The primary end point was death from all causes. RESULTS: The trial was discontinued early, after a mean follow-up period of 24 months, because an interim analysis determined that spironolactone was efficacious. There were 386

  3. SPIRIT 2013 explanation and elaboration: guidance for protocols of clinical trials

    A.-W. Chan, Jennifer Tetzlaff, Peter C Gøtzsche, et al. · 2013 · BMJ · 7,093 citations

    High quality protocols facilitate proper conduct, reporting, and external review of clinical trials. However, the completeness of trial protocols is often inadequate. To help improve the content and quality of protocols, an international group of stakeholders developed the SPIRIT 2013 Statement (Standard Protocol Items: Recommendations for Interventional Trials). The SPIRIT Statement provides guidance in the form of a checklist of recommended items to include in a clinical trial protocol. This SPIRIT 2013 Explanation and Elaboration paper provides important information to promote full understanding of the checklist recommendations. For each checklist item, we provide a rationale and detailed

  4. Implications of Recent Clinical Trials for the National Cholesterol Education Program Adult Treatment Panel III Guidelines

    Scott M. Grundy, James I. Cleeman, C. Noel Bairey Merz, et al. · 2004 · Circulation · 6,934 citations

    The Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program issued an evidence-based set of guidelines on cholesterol management in 2001. Since the publication of ATP III, 5 major clinical trials of statin therapy with clinical end points have been published. These trials addressed issues that were not examined in previous clinical trials of cholesterol-lowering therapy. The present document reviews the results of these recent trials and assesses their implications for cholesterol management. Therapeutic lifestyle changes (TLC) remain an essential modality in clinical management. The trials confirm the benefit of cholesterol-lowering therapy in high-risk patients an

  5. A Placebo-Controlled Trial of Subcutaneous Semaglutide in Nonalcoholic Steatohepatitis

    Philip N. Newsome, Kristine Buchholtz, Kenneth Cusi, et al. · 2020 · New England Journal of Medicine · 1,915 citations

    BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a common disease that is associated with increased morbidity and mortality, but treatment options are limited. The efficacy and safety of the glucagon-like peptide-1 receptor agonist semaglutide in patients with NASH is not known. METHODS: We conducted a 72-week, double-blind phase 2 trial involving patients with biopsy-confirmed NASH and liver fibrosis of stage F1, F2, or F3. Patients were randomly assigned, in a 3:3:3:1:1:1 ratio, to receive once-daily subcutaneous semaglutide at a dose of 0.1, 0.2, or 0.4 mg or corresponding placebo. The primary end point was resolution of NASH with no worsening of fibrosis. The confirmatory secondary end

  6. A Placebo-Controlled Trial of Pioglitazone in Subjects with Nonalcoholic Steatohepatitis

    Renata Belfort, Stephen A. Harrison, Kenneth Brown, et al. · 2006 · New England Journal of Medicine · 1,818 citations

    BACKGROUND: No pharmacologic therapy has conclusively proved to be effective for the treatment of nonalcoholic steatohepatitis, which is characterized by insulin resistance, steatosis, and necroinflammation with or without centrilobular fibrosis. Pioglitazone is a thiazolidinedione that ameliorates insulin resistance and improves glucose and lipid metabolism in type 2 diabetes mellitus. METHODS: We randomly assigned 55 patients with impaired glucose tolerance or type 2 diabetes and liver biopsy-confirmed nonalcoholic steatohepatitis to 6 months of treatment with a hypocaloric diet (a reduction of 500 kcal per day in relation to the calculated daily intake required to maintain body weight) pl

  7. Targeting PI3K in cancer: mechanisms and advances in clinical trials

    Jing Yang, Ji Nie, Xuelei Ma, et al. · 2019 · Molecular Cancer · 1,565 citations

    Phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is one of the most important intracellular pathways, which can be considered as a master regulator for cancer. Enormous efforts have been dedicated to the development of drugs targeting PI3K signaling, many of which are currently employed in clinical trials evaluation, and it is becoming increasingly clear that PI3K inhibitors are effective in inhibiting tumor progression. PI3K inhibitors are subdivided into dual PI3K/mTOR inhibitors, pan-PI3K inhibitors and isoform-specific inhibitors. In this review, we performed a critical review to summarize the role of the PI3K pathway in tumor development, recent PI

  8. Is the Placebo Powerless?

    Asbjørn Hróbjartsson, Peter C Gøtzsche · 2001 · New England Journal of Medicine · 1,512 citations

    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 o

  9. Components of placebo effect: randomised controlled trial in patients with irritable bowel syndrome

    Ted J. Kaptchuk, John M. Kelley, Lisa Conboy, et al. · 2008 · BMJ · 1,202 citations

    OBJECTIVE: To investigate whether placebo effects can experimentally be separated into the response to three components-assessment and observation, a therapeutic ritual (placebo treatment), and a supportive patient-practitioner relationship-and then progressively combined to produce incremental clinical improvement in patients with irritable bowel syndrome. To assess the relative magnitude of these components. DESIGN: A six week single blind three arm randomised controlled trial. SETTING: Academic medical centre. PARTICIPANTS: 262 adults (76% women), mean (SD) age 39 (14), diagnosed by Rome II criteria for and with a score of > or =150 on the symptom severity scale. INTERVENTIONS: For three

  10. A comprehensive review of the placebo effect: recent advances and current thought.

    D. Price, D. Finniss, F. Benedetti · 2008 · Annual review of psychology · 1,159 citations

    Our understanding and conceptualization of the placebo effect has shifted in emphasis from a focus on the inert content of a physical placebo agent to the overall simulation of a therapeutic intervention. Research has identified many types of placebo responses driven by different mechanisms depending on the particular context wherein the placebo is given. Some placebo responses, such as analgesia, are initiated and maintained by expectations of symptom change and changes in motivation/emotions. Placebo factors have neurobiological underpinnings and actual effects on the brain and body. They are not just response biases. Other placebo responses result from less conscious processes, such as cl

  11. Neurobiological Mechanisms of the Placebo Effect

    Fabrizio Benedetti, Helen S. Mayberg, Tor D. Wager, et al. · 2005 · Journal of Neuroscience · 776 citations

    Any medical treatment is surrounded by a psychosocial context that affects the therapeutic outcome. If we want to study this psychosocial context, we need to eliminate the specific action of a therapy and to simulate a context that is similar in all respects to that of a real treatment. To do this,

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

    Lene Vase, Joseph L. Riley, Donald D. Price · 2002 · Pain · 437 citations

    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 pars

  14. Effect of Lactobacillus rhamnosus HN001 in Pregnancy on Postpartum Symptoms of Depression and Anxiety: A Randomised Double-blind Placebo-controlled Trial

    Rebecca F. Slykerman, Fiona Hood, K. Wickens, et al. · 2017 · EBioMedicine · 354 citations

    Background Probiotics may help to prevent symptoms of anxiety and depression through several putative mechanisms. Objective The aim of this study was to evaluate the effect of Lactobacillus rhamnosus HN001 (HN001) given in pregnancy and postpartum on symptoms of maternal depression and anxiety in the postpartum period. This was a secondary outcome, the primary outcome being eczema in the offspring at 12 months of age. Design, Setting, Participants A randomised, double-blind, placebo-controlled trial of the effect of HN001 on postnatal mood was conducted in 423 women in Auckland and Wellington, New Zealand. Women were recruited at 14–16 weeks gestation. Intervention Women were randomised to r

  16. Psychobiological Mechanisms of Placebo and Nocebo Effects: Pathways to Improve Treatments and Reduce Side Effects.

    K. Petrie, W. Rief · 2019 · Annual review of psychology · 263 citations

    Placebo effects constitute a major part of treatment success in medical interventions. The nocebo effect also has a major impact, as it accounts for a significant proportion of the reported side effects for many treatments. Historically, clinical trials have aimed to reduce placebo effects; however, currently, there is interest in optimizing placebo effects to improve existing treatments and in examining ways to minimize nocebo effects to improve clinical outcome. To achieve these aims, a better understanding of the psychological and neurobiological mechanisms of the placebo and nocebo response is required. This review discusses the impact of the placebo and nocebo response in health care. W

  17. The Placebo Effect in Pain Therapies

    L. Colloca · 2018 · Annual review of pharmacology and toxicology · 225 citations

    Pharmacological strategies for pain management have primarily focused on dampening ascending neurotransmission and on opioid receptor-mediated therapies. Little is known about the contribution of endogenous descending modulatory systems to clinical pain outcomes and why some patients are mildly affected while others suffer debilitating pain-induced dysfunctions. Placebo effects that arise from patients’ positive expectancies and the underlying endogenous modulatory mechanisms may in part account for the variability in pain experience and severity, adherence to treatment, distinct coping strategies, and chronicity. Expectancy-induced analgesia and placebo effects in general have emerged as us

  18. Patient Expectancy as a Mediator of Placebo Effects in Antidepressant Clinical Trials

    Bret R Rutherford, M. Wall, Patrick J. Brown, et al. · 2016 · The American journal of psychiatry · 151 citations

    Objective Causes of placebo effects in antidepressant trials have been inferred from observational studies and meta-analyses, but their mechanisms have not been directly established. The goal of this study was to examine in a prospective, randomized controlled trial (RCT) whether patient expectancy mediates placebo effects in antidepressant studies. Method Adult outpatients with Major Depressive Disorder (MDD) were randomized to Open or Placebo-controlled citalopram treatment. Following measurement of pre- and post-randomization expectancy, subjects were treated with citalopram or placebo for 8 weeks. Independent samples t tests determined whether patient expectancy differed between the Open

  20. Placebo-related effects in clinical trials in schizophrenia: what is driving this phenomenon and what can be done to minimize it?

    L. Alphs, F. Benedetti, W. Wolfgang Fleischhacker, et al. · 2012 · The International Journal of Neuropsychopharmacology · 81 citations

    The effect of placebo observed in schizophrenia clinical trials represents a growing problem that interferes with signal detection for treatments, increases costs of development, discourages investment in schizophrenia research and delays the introduction of new treatments. This paper seeks to clarify key issues related to this problem and identify potential solutions to them. Differences between placebo effect and response are characterized. Recent insights into the central nervous system mechanisms of placebo effect are described. This is followed by a description of protocol/study design and study conduct issues that are contributing to a growing placebo effect in clinical trials. Potenti

  21. The Powerful Placebo Effect in Cough: Relevance to Treatment and Clinical Trials

    R. Eccles · 2019 · Lung · 67 citations

    Interest in the placebo effect of medicines has developed from the use of placebo treatments as controls in clinical trials into a whole new area of research around how placebos fit into a psychosocial model of therapeutics. The large placebo effect associated with cough medicines is both a problem and an opportunity for researchers: a problem for clinical trials on new actives as the active must beat the large placebo effect, and an opportunity for harnessing the placebo effect to produce effective cough medicines without any pharmacologically active ingredient. This review discusses the mechanisms associated with the placebo effect of cough medicines and distinguishes between a ‘perceived

  22. The therapeutic effect of clinical trials: understanding placebo response rates in clinical trials – A secondary analysis

    Harald Walach, Catarina Sadaghiani, Cornelia Dehm, et al. · 2005 · BMC Medical Research Methodology · 62 citations

    Abstract Background and purpose Placebo response rates in clinical trials vary considerably and are observed frequently. For new drugs it can be difficult to prove effectiveness superior to placebo. It is unclear what contributes to improvement in the placebo groups. We wanted to clarify, what elements of clinical trials determine placebo variability. Methods We analysed a representative sample of 141 published long-term trials (randomized, double-blind, placebo-controlled; duration > 12 weeks) to find out what study characteristics predict placebo response rates in various diseases. Correlational and regress

  23. Effect of Empagliflozin on Endothelial Function in Patients With Type 2 Diabetes and Cardiovascular Disease: Results from the Multicenter, Randomized, Placebo-Controlled, Double-Blind EMBLEM Trial

    Atsushi Tanaka, M. Shimabukuro, Noritaka Machii, et al. · 2019 · Diabetes Care · 53 citations

    Recent large trials on sodium–glucose cotransporter 2 (SGLT2) inhibitors showed that these agents improved cardiovascular outcomes in patients with type 2 diabetes (T2D) with a high risk of cardiovascular events (1). However, the underlying mechanisms of these clinical benefits and vascular effect of SGLT2 inhibitors in that patient group remain uncertain. Endothelial dysfunction is exacerbated by metabolic disorders, such as diabetes, and involved in the pathophysiology of diabetes-related cardiovascular complications (2,3). We therefore investigated whether empagliflozin added to standard therapy, compared with placebo, affected endothelial function in patients with T2D and established car

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