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Nordic, Denmark

Jorgensen K.J.,Nordic Cochrane Center
Danish medical journal | Year: 2013

The rationale for breast cancer screening with mammography is deceptively simple: catch it early and reduce mortality from the disease and the need for mastectomies. But breast cancer is a complex problem, and complex problems rarely have simple solutions. Breast screening brings forward the time of diagnosis only slightly compared to the lifetime of a tumour, and screen-detected tumours have a size where metastases are possible. A key question is if screening can prevent metastases, and if the screen-detected tumours are small enough to allow breast conserving surgery rather than mastectomy. A mortality reduction can never justify a medical intervention in its own right, but must be weighed against the harms. Overdiagnosis is the most important harm of breast screening, but has gained wider recognition only in recent years. Screening leads to the detection and treatment of breast cancers that would otherwise never have been detected because they grow very slowly or not at all and would not have been detected in the woman's lifetime in the absence of screening. Screening therefore turns women into cancer patients unnecessarily, with life-long physical and psychological harms. The debate about the justification of breast screening is therefore not a simple question of whether screening reduces breast cancer mortality. This dissertation quantifies the primary benefits and harms of screening mammography. Denmark has an unscreened "control group" because only two geographical regions offered screening over a long time-period, which is unique in an international context. This was used to study breast cancer mortality, overdiagnosis, and the use of mastectomies. Also, a systematic review of overdiagnosis in five other countries allowed us to show that about half of the screen-detected breast cancers are overdiagnosed. An effect on breast cancer mortality is doubtful in today's setting, and overdiagnosis causes an increase in the use of mastectomies. These findings are discussed in the context of tumour biology and stage at diagnosis. The information provided to women in invitations and on the Internet exaggerates benefits, participation is directly recommended, and the harms are downplayed or left out, despite agreement that the objective is informed choice. This raises an ethical discussion concerning autonomy versus paternalism, and the difficulty in weighing benefits against harms. Finally, financial, political, and professional conflicts of interest are discussed, as well as health economics. Source


Gotzsche P.C.,Nordic Cochrane Center
Polskie Archiwum Medycyny Wewnetrznej | Year: 2014

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". Copyright by Medycyna Praktyczna, Kraków 2014 Source


Hrobjartsson A.,Nordic Cochrane Center | Kaptchuk T.J.,Beth Israel Deaconess Medical Center | Miller F.G.,U.S. National Institutes of Health
Journal of Clinical Epidemiology | Year: 2011

Objective: Investigations of the effect of placebo are often challenging to conduct and interpret. The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo. Study Design and Setting: A methodological analysis and discussion. Results: The inherent nonblinded comparison between placebo and no-treatment is the best research design we have in estimating effects of placebo, both in a clinical and in an experimental setting, but the difference between placebo and no-treatment remains an approximate and fairly crude reflection of the true effect of placebo interventions. A main problem is response bias in trials with outcomes that are based on patients' reports. Other biases involve differential co-intervention and patient dropouts, publication bias, and outcome reporting bias. Furthermore, extrapolation of results to a clinical settings are challenging because of a lack of clear identification of the causal factors in many clinical trials, and the nonclinical setting and short duration of most laboratory experiments. Conclusions: Creative experimental efforts are needed to assess rigorously the clinical significance of placebo interventions and investigate the component elements that may contribute to the therapeutic benefit. © 2011 Elsevier Inc. All rights reserved. Source


Chan A.-W.,University of Toronto | Song F.,University of East Anglia | Vickers A.,Sloan Kettering Cancer Center | Jefferson T.,Cochrane Collaboration | And 7 more authors.
The Lancet | Year: 2014

The methods and results of health research are documented in study protocols, full study reports (detailing all analyses), journal reports, and participant-level datasets. However, protocols, full study reports, and participant-level datasets are rarely available, and journal reports are available for only half of all studies and are plagued by selective reporting of methods and results. Furthermore, information provided in study protocols and reports varies in quality and is often incomplete. When full information about studies is inaccessible, billions of dollars in investment are wasted, bias is introduced, and research and care of patients are detrimentally aff ected. To help to improve this situation at a systemic level, three main actions are warranted. First, academic institutions and funders should reward investigators who fully disseminate their research protocols, reports, and participant-level datasets. Second, standards for the content of protocols and full study reports and for data sharing practices should be rigorously developed and adopted for all types of health research. Finally, journals, funders, sponsors, research ethics committees, regulators, and legislators should endorse and enforce policies supporting study registration and wide availability of journal reports, full study reports, and participant-level datasets. Source


Hrobjartsson A.,Nordic Cochrane Center | Boutron I.,French Institute of Health and Medical Research | Boutron I.,University of Paris Descartes
Clinical Pharmacology and Therapeutics | Year: 2011

Blinding, or masking, is a crucial method for reducing bias in randomized clinical trials. In this paper, we review important methodological aspects of blinding, emphasizing terminology, reporting, bias mechanisms, empirical evidence, and the risk of unblinding. Theoretical considerations and empirical analyses support the blinding of patients, health-care providers, and outcome assessors as to the trial intervention to which patients have been allocated. We encourage extensive pretrial testing of blinding procedures and explicit reporting of who was in the blinded condition and the methods used to ensure blinding. © 2011 American Society for Clinical Pharmacology and Therapeutics. Source

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