Abstract:
OBJECTIVE:To assess the waste of research related to inadequate methods in trials included in Cochrane reviews and to examine to what extent this waste could be avoided. A secondary objective was to perform a simulation study to re-estimate this avoidable waste if all trials were adequately reported. DESIGN:Methodological review and simulation study. DATA SOURCES:Trials included in the meta-analysis of the primary outcome of Cochrane reviews published between April 2012 and March 2013. DATA EXTRACTION AND SYNTHESIS:We collected the risk of bias assessment made by the review authors for each trial. For a random sample of 200 trials with at least one domain at high risk of bias, we re-assessed risk of bias and identified all related methodological problems. For each problem, possible adjustments were proposed that were then validated by an expert panel also evaluating their feasibility (easy or not) and cost. Avoidable waste was defined as trials with at least one domain at high risk of bias for which easy adjustments with no or minor cost could change all domains to low risk. In the simulation study, after extrapolating our re-assessment of risk of bias to all trials, we considered each domain rated as unclear risk of bias as missing data and used multiple imputations to determine whether they were at high or low risk. RESULTS:Of 1286 trials from 205 meta-analyses, 556 (43%) had at least one domain at high risk of bias. Among the sample of 200 of these trials, 142 were confirmed as high risk; in these, we identified 25 types of methodological problem. Adjustments were possible in 136 trials (96%). Easy adjustments with no or minor cost could be applied in 71 trials (50%), resulting in 17 trials (12%) changing to low risk for all domains. So the avoidable waste represented 12% (95% CI 7% to 18%) of trials with at least one domain at high risk. After correcting for incomplete reporting, avoidable waste due to inadequate methods was estimated at 42% (95% CI 36% to 49%). CONCLUSIONS:An important burden of wasted research is related to inadequate methods. This waste could be partly avoided by simple and inexpensive adjustments.
journal_name
BMJjournal_title
BMJ (Clinical research ed.)authors
Yordanov Y,Dechartres A,Porcher R,Boutron I,Altman DG,Ravaud Pdoi
10.1136/bmj.h809subject
Has Abstractpub_date
2015-03-24 00:00:00pages
h809eissn
0959-8138issn
1756-1833journal_volume
350pub_type
杂志文章abstract:OBJECTIVE:To evaluate risk of late life coronary heart disease associated with being overweight in late middle or old age and to assess whether weight change modifies this risk. DESIGN:Longitudinal study of subjects in the epidemiological follow up study of the national health and nutrition examination survey I. SETT...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.314.7097.1791
更新日期:1997-06-21 00:00:00
abstract:OBJECTIVES:To describe the change in first day infant mortality during 1935-87. To examine the hypothesis that excess first day mortality in the 1950s and 1960s was attributable to restricting oxygen for sick newborn infants. DESIGN:Time series analysis of first day infant mortality and stillbirth rates. SETTING:Engl...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.304.6823.343
更新日期:1992-02-08 00:00:00
abstract:OBJECTIVE:To examine the extent of uptake of medication for secondary prevention of coronary heart disease in older British men and women before (1998-2001) and after (2003) the implementation of the national service framework. DESIGN:Two population based, longitudinal studies of men and women aged 60-79 in 1998-2001,...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,多中心研究
doi:10.1136/bmj.38704.770127.BE
更新日期:2006-01-21 00:00:00
abstract:OBJECTIVE:To investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field. DESIGN:A population based case-control study. SETTING:Denmark. SUBJECTS:1707 children under the age of 15 wit...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.307.6909.891
更新日期:1993-10-09 00:00:00
abstract:OBJECTIVE:To review the evidence for ethnic differences in susceptibility to adverse drug reactions (ADRs) to cardiovascular drugs. DESIGN:Systematic review and meta-analysis. DATA SOURCES:We searched Medline and Embase to March 2005. Reference lists of identified articles were hand searched for further relevant arti...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,meta分析,评审
doi:10.1136/bmj.38803.528113.55
更新日期:2006-05-20 00:00:00
abstract:OBJECTIVE:To assess whether causal criteria can be used to find out whether there is support in published research for maintaining that menopause causes depression. DESIGN:Ninety four articles from 30 years of research examining the relation of natural menopause to depression were traced by using Medline and systemati...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,评审
doi:10.1136/bmj.313.7067.1229
更新日期:1996-11-16 00:00:00
abstract:OBJECTIVE:To describe the mechanism established by Richmond, Twickenham, and Roehampton Health Authority to manage extracontractual referral requests made on behalf of its resident population and to examine its working in the first three months of the new arrangements. DESIGN:Description of the procedures for managing...
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pub_type: 杂志文章
doi:10.1136/bmj.303.6801.499
更新日期:1991-08-31 00:00:00
abstract:OBJECTIVE:To assess the effects of social deprivation on survival after cardiac surgery and to examine the influence of potentially modifiable risk factors. DESIGN:Analysis of prospectively collected data. Prognostic models used to examine the additional effect of social deprivation on the end points. SETTING:Birming...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,多中心研究
doi:10.1136/bmj.b902
更新日期:2009-04-02 00:00:00
abstract:OBJECTIVE:To determine whether women with atrial fibrillation have a higher risk of stroke than men. DESIGN:Nationwide retrospective cohort study. SETTING:Patients with a diagnosis of atrial fibrillation in the Swedish hospital discharge register between 1 July 2005 and 31 December 2008. Information about drug treatm...
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pub_type: 杂志文章
doi:10.1136/bmj.e3522
更新日期:2012-05-30 00:00:00
abstract:OBJECTIVES:To determine the accuracy of a clinical decision rule (the traffic light system developed by the National Institute for Health and Clinical Excellence (NICE)) for detecting three common serious bacterial infections (urinary tract infection, pneumonia, and bacteraemia) in young febrile children. DESIGN:Retro...
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pub_type: 杂志文章
doi:10.1136/bmj.f866
更新日期:2013-02-13 00:00:00
abstract:OBJECTIVE:To evaluate the effectiveness and costs of a multifaceted flexible educational programme aimed at reducing antibiotic dispensing at the practice level in primary care. DESIGN:Randomised controlled trial with general practices as the unit of randomisation and analysis. Clinicians and researchers were blinded ...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1136/bmj.d8173
更新日期:2012-02-02 00:00:00
abstract:OBJECTIVE:To estimate the risk of acute hepatotoxicity associated with nimesulide compared with other non-steroidal anti-inflammatory drugs. DESIGN:Retrospective cohort and nested case-control study. SETTING:Umbria region, Italy. PARTICIPANTS:400 000 current, recent, and past users (almost 2 million prescriptions) o...
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pub_type: 杂志文章
doi:10.1136/bmj.327.7405.18
更新日期:2003-07-05 00:00:00
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pub_type: 杂志文章
doi:10.1136/bmj.301.6752.584
更新日期:1990-09-22 00:00:00
abstract::The introduction in Britain of advance directives--which allow a person to state in advance of becoming incompetent that they wish to take part in treatment decisions when no longer mentally competent--has now been advocated by the medical and legal establishments. The practical application of directives relating to h...
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pub_type: 杂志文章
doi:10.1136/bmj.310.6974.236
更新日期:1995-01-28 00:00:00
abstract:OBJECTIVE:To determine whether peer review medical audit in a primary care setting changes clinical behaviour in relation to the management of hypertension. DESIGN:Review of medical records in general practices to identify hypertensive patients followed up by assessment of the pre-educational and post-educational mana...
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pub_type: 杂志文章
doi:10.1136/bmj.314.7085.942
更新日期:1997-03-29 00:00:00
abstract:OBJECTIVE:To compare the prevalence of silent myocardial ischaemia associated with coronary artery disease in diabetic subjects with that in controls of similar age and sex. DESIGN:A controlled study in which subjects with positive findings on exercise electrocardiography, 24 hour electrocardiographic recording, or dy...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.301.6743.92
更新日期:1990-07-14 00:00:00
abstract:OBJECTIVE:To examine whether, according to the conclusions of a 2000 systematic review with meta-analysis on interventions to prevent pain from propofol injection that provided a research agenda to guide further research on the topic, subsequently published trials were more often optimally blinded, reported on children...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,评审
doi:10.1136/bmj.g5219
更新日期:2014-08-26 00:00:00
abstract:OBJECTIVE:To measure the prevalence of breast feeding and to examine the value of using information collected on Guthrie cards (used for detecting inherited metabolic disease and hypothyroidism when newborn infants are 7 days old) to calculate this prevalence. DESIGN:Analysis, by geographical area and maternity unit, ...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.308.6932.824
更新日期:1994-03-26 00:00:00
abstract::Objective To improve the selection of patients with acute ischaemic stroke for intra-arterial treatment using a clinical decision tool to predict individual treatment benefit.Design Multivariable regression modelling with data from two randomised controlled clinical trials.Setting 16 hospitals in the Netherlands (deri...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1136/bmj.j1710
更新日期:2017-05-03 00:00:00
abstract:OBJECTIVE:To determine the outcome of administration of neuroleptics to patients with senile dementia of Lewy body type confirmed at necropsy. DESIGN:Retrospective analysis of clinical notes blind to neuropathological diagnosis. SETTING:Specialist psychogeriatric assessment units referring cases for necropsy to a tea...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.305.6855.673
更新日期:1992-09-19 00:00:00
abstract::Monocycline is the most widely prescribed systemic antibiotic for acne largely because it needs to be given only once or twice a day and seems not to induce resistance. Up to April 1994 11 cases of minocycline induced systemic lupus erythematosus and 16 cases of hepatitis had been reported to the Committee on Safety o...
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pub_type: 杂志文章
doi:10.1136/bmj.312.7024.169
更新日期:1996-01-20 00:00:00
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journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.h3786
更新日期:2015-07-31 00:00:00
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pub_type: 杂志文章
doi:10.1136/bmj.316.7131.589
更新日期:1998-02-21 00:00:00
abstract:OBJECTIVE:To determine which treatments for preventing coronary heart disease should be offered to which patients by assessing their incremental cost effectiveness. DESIGN:Modelling study. DATA SOURCES:Cost estimates (for NHS) and estimates of effectiveness obtained for aspirin, antihypertensive drugs, statins and cl...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.327.7426.1264
更新日期:2003-11-29 00:00:00
abstract:OBJECTIVES:To assess whether blood pressure control in primary care could be improved with the use of patient held targets and self monitoring in a practice setting, and to assess the impact of these on health behaviours, anxiety, prescribed antihypertensive drugs, patients' preferences, and costs. DESIGN:Randomised c...
journal_title:BMJ (Clinical research ed.)
pub_type: 临床试验,杂志文章,多中心研究,随机对照试验
doi:10.1136/bmj.38558.393669.E0
更新日期:2005-09-03 00:00:00
abstract:OBJECTIVE:To describe and quantify patterns of injury from antipersonnel mines in terms of distribution of injury, drain on surgical resources, and residual disability. DESIGN:Retrospective analysis. SETTING:Two hospitals for patients injured in war. SUBJECTS:757 patients with injuries from antipersonnel mines. MAI...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.303.6816.1509
更新日期:1991-12-14 00:00:00
abstract:OBJECTIVE:To characterise the complete case series of influenza A/H7N9 infections as of 27 May 2013, detected by China's national sentinel surveillance system for influenza-like illness. DESIGN:Case series. SETTING:Outpatient clinics and emergency departments of 554 sentinel hospitals across 31 provinces in mainland ...
journal_title:BMJ (Clinical research ed.)
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doi:10.1136/bmj.f3693
更新日期:2013-06-24 00:00:00
abstract:OBJECTIVE:To examine the distribution of patterns of macronutrient density in relation to obesity. DESIGN:Cross sectional. SETTING:Denmark. SUBJECTS:323 men and women aged 35-65 years, selected randomly from a larger population sample of Danish adults. MAIN OUTCOME MEASURE:Bias in dietary reporting of energy and pr...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.311.7011.986
更新日期:1995-10-14 00:00:00
abstract:OBJECTIVE:To describe the progression of HIV disease in a haemophilic cohort and to show the influence of treatment. DESIGN:11 year longitudinal clinical and laboratory study. SETTING:A haemophilia centre. PATIENTS:111 patients infected with HIV during October 1979 to July 1985. MAIN OUTCOME MEASURES:Symptoms of HI...
journal_title:BMJ (Clinical research ed.)
pub_type: 临床试验,杂志文章
doi:10.1136/bmj.303.6810.1093
更新日期:1991-11-02 00:00:00
abstract:OBJECTIVE:To determine prevalence of HIV infection and drug injecting behaviour among inmates of Glenochil Prison on a specified date a year after an outbreak of hepatitis B and HIV infection. DESIGN:Cross sectional: voluntary, anonymous HIV salivary antibody surveillance and linked self completion questionnaire on ri...
journal_title:BMJ (Clinical research ed.)
pub_type: 杂志文章
doi:10.1136/bmj.310.6975.293
更新日期:1995-02-04 00:00:00