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Peter C Gøtzsche

Bio: Peter C Gøtzsche is an academic researcher from Cochrane Collaboration. The author has contributed to research in topics: Systematic review & Placebo. The author has an hindex of 90, co-authored 413 publications receiving 147009 citations. Previous affiliations of Peter C Gøtzsche include University of Copenhagen & Copenhagen University Hospital.


Papers
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Journal ArticleDOI
TL;DR: The Small Arms Survey occasional paper series presents new and substantial research findings by project staff and commissioned researchers on data, methodological, and conceptual issues related to small arms, or detailed country and regional case studies.

14 citations

Journal Article
TL;DR: There is no need to use several observers or repeated measurements of waist, hip and SagD in clinical anti-obesity trials, according to an out-patient weight loss study of 63 patients.
Abstract: In an out-patient weight loss study of 63 patients (54 female, 9 male), 53 completed a 16 week treatment with a low calorie diet and a 9 g/day fibre supplement. In these 53 patients, the average weight loss was 8.3 kg (s.e.m. 0.8). Waist-hip ratio (WHR) and abdominal sagittal diameter (SagD) were measured as indicators of fat distribution and visceral adipose tissue (visceral AT) was estimated by anthropometric computerized tomography calibrated equations. Four observers measured WHR and SagD ten times in eight patients. Two dietitians examined the patients throughout the clinical trial at weeks 0, 4, 8 and 16. Furthermore, two physicians examined the patients at week 12 in the trial. Two- and three-way analyses of variance were performed to estimate the contribution of single factors to the total variance. The contribution of observers, 3.2% and 3.8%, respectively, was of the same magnitude as the error variance (2.9% and 4.8% respectively) which is a measure of the intra-observer variation. The two dietitians had very similar recordings and contributed only 0.3% and 0.9% to the total variance for WHR and SagD, respectively. The contributions of the two physicians to the total variance were 0.0% for WHR and 0.4% for SagD. It is concluded that there is no need to use several observers or repeated measurements of waist, hip and SagD in clinical anti-obesity trials.

14 citations

Journal ArticleDOI
TL;DR: The authors should take far fewer drugs, and patients should carefully study the package inserts of the drugs their doctors prescribe for them and independent information sources about drugs such as Cochrane reviews, which will make it easier for them to say "no thanks".
Abstract: Our prescription drugs are the third leading cause of death after heart disease and cancer in the United States and Europe. Around half of those who die have taken their drugs correctly; the other half die because of errors, such as too high a dose or use of a drug despite contraindications. Our drug agencies are not particularly helpful, as they rely on fake fixes, which are a long list of warnings, precautions, and contraindications for each drug, although they know that no doctor can possibly master all of these. Major reasons for the many drug deaths are impotent drug regulation, widespread crime that includes corruption of the scientific evidence about drugs and bribery of doctors, and lies in drug marketing, which is as harmful as tobacco marketing and, therefore, should be banned. We should take far fewer drugs, and patients should carefully study the package inserts of the drugs their doctors prescribe for them and independent information sources about drugs such as Cochrane reviews, which will make it easier for them to say "no thanks".

13 citations

Book
01 Jan 2013
TL;DR: Busting the industry myths, the business model of big pharma, Psychiatrists as drug pushers and more lies about happy pills are revealed.

13 citations

Journal Article
TL;DR: Tight sponsor control over industry-initiated clinical trial protocols should be changed.
Abstract: In 22 of 44 industry-initiated clinical trial protocols from 1994-95, it was noted that the sponsor either owned the data or needed to approve the manuscript; another 18 protocols had other constraints. Furthermore, in 16 trials, the sponsor had access to accumulating data, and in an additional 16 trials the sponsor could stop the trial at any time, for any reason. These facts were not noted in any of the trial reports. We found similar constraints on publication rights in 44 protocols from 2004. This tight sponsor control over industry-initiated trials should be changed.

13 citations


Cited by
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Journal ArticleDOI
TL;DR: Moher et al. as mentioned in this paper introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses, which is used in this paper.
Abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

62,157 citations

Journal Article
TL;DR: The QUOROM Statement (QUality Of Reporting Of Meta-analyses) as mentioned in this paper was developed to address the suboptimal reporting of systematic reviews and meta-analysis of randomized controlled trials.
Abstract: Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field,1,2 and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research,3 and some health care journals are moving in this direction.4 As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews. Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in 4 leading medical journals in 1985 and 1986 and found that none met all 8 explicit scientific criteria, such as a quality assessment of included studies.5 In 1987, Sacks and colleagues6 evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in 6 domains. Reporting was generally poor; between 1 and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement.7 In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials.8 In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1). Box 1 Conceptual issues in the evolution from QUOROM to PRISMA

46,935 citations

Journal ArticleDOI
13 Sep 1997-BMJ
TL;DR: Funnel plots, plots of the trials' effect estimates against sample size, are skewed and asymmetrical in the presence of publication bias and other biases Funnel plot asymmetry, measured by regression analysis, predicts discordance of results when meta-analyses are compared with single large trials.
Abstract: Objective: Funnel plots (plots of effect estimates against sample size) may be useful to detect bias in meta-analyses that were later contradicted by large trials. We examined whether a simple test of asymmetry of funnel plots predicts discordance of results when meta-analyses are compared to large trials, and we assessed the prevalence of bias in published meta-analyses. Design: Medline search to identify pairs consisting of a meta-analysis and a single large trial (concordance of results was assumed if effects were in the same direction and the meta-analytic estimate was within 30% of the trial); analysis of funnel plots from 37 meta-analyses identified from a hand search of four leading general medicine journals 1993-6 and 38 meta-analyses from the second 1996 issue of the Cochrane Database of Systematic Reviews . Main outcome measure: Degree of funnel plot asymmetry as measured by the intercept from regression of standard normal deviates against precision. Results: In the eight pairs of meta-analysis and large trial that were identified (five from cardiovascular medicine, one from diabetic medicine, one from geriatric medicine, one from perinatal medicine) there were four concordant and four discordant pairs. In all cases discordance was due to meta-analyses showing larger effects. Funnel plot asymmetry was present in three out of four discordant pairs but in none of concordant pairs. In 14 (38%) journal meta-analyses and 5 (13%) Cochrane reviews, funnel plot asymmetry indicated that there was bias. Conclusions: A simple analysis of funnel plots provides a useful test for the likely presence of bias in meta-analyses, but as the capacity to detect bias will be limited when meta-analyses are based on a limited number of small trials the results from such analyses should be treated with considerable caution. Key messages Systematic reviews of randomised trials are the best strategy for appraising evidence; however, the findings of some meta-analyses were later contradicted by large trials Funnel plots, plots of the trials9 effect estimates against sample size, are skewed and asymmetrical in the presence of publication bias and other biases Funnel plot asymmetry, measured by regression analysis, predicts discordance of results when meta-analyses are compared with single large trials Funnel plot asymmetry was found in 38% of meta-analyses published in leading general medicine journals and in 13% of reviews from the Cochrane Database of Systematic Reviews Critical examination of systematic reviews for publication and related biases should be considered a routine procedure

37,989 citations

Journal ArticleDOI
TL;DR: In this review the usual methods applied in systematic reviews and meta-analyses are outlined, and the most common procedures for combining studies with binary outcomes are described, illustrating how they can be done using Stata commands.

31,656 citations

Journal ArticleDOI
TL;DR: A structured summary is provided including, as applicable, background, objectives, data sources, study eligibility criteria, participants, interventions, study appraisal and synthesis methods, results, limitations, conclusions and implications of key findings.

31,379 citations