Abstract:
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.
journal_name
Cochrane Database Syst Revjournal_title
The Cochrane database of systematic reviewsauthors
Hróbjartsson A,Gøtzsche PCdoi
10.1002/14651858.CD003974.pub2keywords:
subject
Has Abstractpub_date
2004-01-01 00:00:00pages
CD003974issue
3issn
1469-493Xpub_type
杂志文章,meta分析,评审abstract:BACKGROUND:The decision to enter long-term care is often a major life event for older people, made in the context of personal crisis and loss. We hypothesised that the process through which a decision to enter long-term residential care emerges affects the overall psycho-social adjustment to, and acceptance of, this de...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD005213.pub2
更新日期:2007-07-18 00:00:00
abstract:BACKGROUND:Perineal trauma is common during childbirth and may be painful. Contemporary maternity practice includes offering women numerous forms of pain relief, including the local application of cooling treatments. This Cochrane Review is an update of a review last updated in 2012. OBJECTIVES:To evaluate the effecti...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD006304.pub4
更新日期:2020-10-09 00:00:00
abstract:BACKGROUND:This is an update of a Cochrane Review first published in 2005. Surgery has been used to treat persistent pain and dysfunction at the base of the thumb. However, there is no evidence to suggest that any one surgical procedure is superior to another. OBJECTIVES:To compare the effect of different surgical tec...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD004631.pub3
更新日期:2009-10-07 00:00:00
abstract:BACKGROUND:Reduced ankle dorsiflexion range of motion, or ankle equinus, is a common and disabling problem for patients with neuromuscular disease. Clinicians devote considerable time and resources implementing interventions to correct this problem although few of these interventions have been subject to rigorous empir...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006973.pub2
更新日期:2010-02-17 00:00:00
abstract:BACKGROUND:Initial resuscitation with air is well tolerated by most infants born at term. However, the optimal fractional inspired oxygen concentration (FiO2 - proportion of the breathed air that is oxygen) targeted to oxygen saturation (SpO2 - an estimate of the amount of oxygen in the blood) for infants born preterm ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010239.pub2
更新日期:2018-05-04 00:00:00
abstract:BACKGROUND:This is an update of a Cochrane Review first published in The Cochrane Library in Issue 1, 2002 and previously updated in 2004 and 2007.Benign paroxysmal positional vertigo (BPPV) is a syndrome characterised by short-lived episodes of vertigo in association with rapid changes in head position. It is a common...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003162.pub3
更新日期:2014-12-08 00:00:00
abstract:BACKGROUND:Adenoidectomy, surgical removal of the adenoids, is a common ENT operation worldwide in children with otitis media. A systematic review on the effectiveness of adenoidectomy in this specific group has not previously been performed. OBJECTIVES:To assess the effectiveness of adenoidectomy versus non-surgical ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD007810.pub2
更新日期:2010-01-20 00:00:00
abstract:BACKGROUND:Angiotensin receptor blockers (ARBs) are widely prescribed for hypertension so it is essential to determine and compare their effects on blood pressure (BP), heart rate and withdrawals due to adverse effects (WDAE). OBJECTIVES:To quantify the dose-related systolic and/or diastolic BP lowering efficacy of AR...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003822.pub2
更新日期:2008-10-08 00:00:00
abstract:BACKGROUND:Voluntary counseling and testing (VCT) continues to play a critical role in HIV prevention, care and treatment. In recent years, different modalities of VCT have been implemented, including clinic-, mobile- and home-based testing and counseling. This review assesses the effects of all VCT types on HIV-relate...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001224.pub4
更新日期:2012-09-12 00:00:00
abstract:BACKGROUND:Specific treatments for influenza are limited to neuraminidase inhibitors and adamantanes. Corticosteroids show evidence of benefit in sepsis and related conditions, most likely due to their anti-inflammatory and immunomodulatory properties. Although commonly prescribed for severe influenza, there is uncerta...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD010406.pub3
更新日期:2019-02-24 00:00:00
abstract:BACKGROUND:The pathogenesis of hepatic encephalopathy is unknown. It has been suggested that liver failure leads to the accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition which may progress to coma. Several trials have assessed benzodiazepine receptor antagonists for ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002798
更新日期:2001-01-01 00:00:00
abstract:BACKGROUND:In osteogenesis imperfecta (OI) a genetic defect in type I collagen results in multiple fractures with little or no trauma. Bisphosphonates are used to attempt to reduce these fractures. OBJECTIVES:To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density (BMD), reducing f...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD005088.pub2
更新日期:2008-10-08 00:00:00
abstract:BACKGROUND:The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator, preventing bacterial clearance and allowing persistence of pro-inflammatory mediators. Conventional treatment with physiothera...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001392.pub3
更新日期:2015-08-13 00:00:00
abstract:BACKGROUND:Premenstrual syndrome (PMS) is a common problem. Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome. Combined oral contraceptives, which provide both progestin and estrogen, have been examined for their ability to relieve premenstrual symptoms. An oral contraceptive containing d...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006586.pub4
更新日期:2012-02-15 00:00:00
abstract:BACKGROUND:The behavioural problems of people with dementia are often considered as one of the most challenging issues in caring. Special Care Units (SCUs) have flourished since the 1980s with the aim of taking care of dementia patients, usually those with Alzheimer's disease, and in particular for those with behaviour...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006470.pub2
更新日期:2009-10-07 00:00:00
abstract:BACKGROUND:Postpartum haemorrhage (PPH) - heaving bleeding within the first 24 hours after giving birth - is one of the main causes of death of women after childbirth. Antifibrinolytics, primarily tranexamic acid (TXA), have been shown to reduce bleeding in surgery and safely reduces mortality in trauma patients with b...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD012964
更新日期:2018-02-20 00:00:00
abstract:BACKGROUND:Haemorrhoids is a common perianal disease, which often causes haematochezia. Besides a surgical operation or minimally invasive treatment, a variety of traditional Chinese medicinal herbs (TCMHs) have been used to treat bleeding haemorrhoids. OBJECTIVES:To assess the effectiveness of traditional Chinese med...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD006791.pub2
更新日期:2010-10-06 00:00:00
abstract::This is the protocol for a review and there is no abstract. The objectives are as follows: 1 PRIMARY OBJECTIVES:To evaluate clinically meaningful benefits of interventions used to treat clinically significant obsessive compulsive symptoms occurring in people with schizophrenia with regard to global improvement, chang...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章
doi:10.1002/14651858.CD005236
更新日期:2005-01-01 00:00:00
abstract:BACKGROUND:Obstructive sleep apnoea is the periodic reduction (hypopnoea) or cessation (apnoea) of breathing due to narrowing or occlusion of the upper airway during sleep. The main symptom is daytime sleepiness and it has been suggested it is linked to premature death, hypertension, ischaemic heart disease, stroke and...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD001106.pub3
更新日期:2006-07-19 00:00:00
abstract:BACKGROUND:Comprehensive geriatric assessment (CGA) is a multi-dimensional, multi-disciplinary diagnostic and therapeutic process conducted to determine the medical, mental, and functional problems of older people with frailty so that a co-ordinated and integrated plan for treatment and follow-up can be developed. This...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006211.pub3
更新日期:2017-09-12 00:00:00
abstract:BACKGROUND:In view of the claims and counter-claims of the effectiveness of transcutaneous electrical nerve stimulation, it would seem appropriate to systematically review the literature. OBJECTIVES:To determine the effectiveness of transcutaneous electrical nerve stimulation in reducing pain and improving range of mo...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000210.pub2
更新日期:2007-07-18 00:00:00
abstract:BACKGROUND:Asthma is a common respiratory condition in children that is characterised by symptoms including wheeze, shortness of breath, chest tightness, and cough. Children with asthma may be able to manage their condition more effectively by improving inhaler technique, and by recognising and responding to symptoms. ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD011651.pub2
更新日期:2019-01-28 00:00:00
abstract:BACKGROUND:A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health ou...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001005
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Absence seizures are brief epileptic seizures which present in childhood and adolescence. They are characterised by sudden loss of awareness and an electroencephalogram (EEG) typically shows generalised spike wave discharges at three cycles per second. Ethosuximide, valproate and lamotrigine are currently us...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003032
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health ou...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001117
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Baby-led breastfeeding is recommended as best practice in determining the frequency and duration of a breastfeed. An alternative approach is described as scheduled, where breastfeeding is timed and restricted in frequency and duration. It is necessary to review the evidence that supports current recommendati...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD009067.pub2
更新日期:2014-07-31 00:00:00
abstract:BACKGROUND:Hirsutism is the presence of excessive hair growth in women and is an important cosmetic condition often resulting in severe distress. Hirsutism is most often caused by increased production of male sex hormones also known as androgens. It is also affected by increased sensitivity to androgens in the hair fol...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000194
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Treatment of cerebral sinus thrombosis with thrombolytics has been reported in cases with a deteriorating clinical course despite anticoagulant therapy. The rationale of this treatment is to promote rapid recanalisation of the occluded sinus. OBJECTIVES:To review the available evidence on the efficacy and s...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003693.pub2
更新日期:2004-01-01 00:00:00
abstract:BACKGROUND:Gastro-oesophageal reflux (GOR) is commonly diagnosed in the neonatal population (DiPietro 1994), and generally causes few or no symptoms (Vandenplas 2009). Conversely, gastro-oesophageal reflux disease (GORD) refers to GOR that causes troublesome symptoms with or without complications such as damage to the ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD009817.pub2
更新日期:2014-10-15 00:00:00
abstract:BACKGROUND:Bisphosphonate drugs can be used to prevent and treat osteoporosis and to reduce symptoms and complications of metastatic bone disease; however, they are associated with a rare but serious adverse event: osteonecrosis of the maxillary and mandibular bones. This condition is called bisphosphonate-related oste...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD008455.pub2
更新日期:2016-02-26 00:00:00