Healthy Skepticism Library item: 17977

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Publication type: Journal Article

McGauran N, Wieseler B, Kreis J, Schüler Y-B, Kölsch H, Kaiser T
Reporting bias in medical research - a narrative review
Trials 2010; 11:(1):37
http://www.trialsjournal.com/content/pdf/1745-6215-11-37.pdf

Abstract:

Reporting bias represents a major problem in the assessment of health care interventions. Several prominent cases
have been described in the literature, for example, in the reporting of trials of antidepressants, Class I anti-arrhythmic
drugs, and selective COX-2 inhibitors. The aim of this narrative review is to gain an overview of reporting bias in the
medical literature, focussing on publication bias and selective outcome reporting. We explore whether these types of
bias have been shown in areas beyond the well-known cases noted above, in order to gain an impression of how
widespread the problem is. For this purpose, we screened relevant articles on reporting bias that had previously been
obtained by the German Institute for Quality and Efficiency in Health Care in the context of its health technology
assessment reports and other research work, together with the reference lists of these articles.
We identified reporting bias in 40 indications comprising around 50 different pharmacological, surgical (e.g. vacuumassisted
closure therapy), diagnostic (e.g. ultrasound), and preventive (e.g. cancer vaccines) interventions. Regarding
pharmacological interventions, cases of reporting bias were, for example, identified in the treatment of the following
conditions: depression, bipolar disorder, schizophrenia, anxiety disorder, attention-deficit hyperactivity disorder,
Alzheimer’s disease, pain, migraine, cardiovascular disease, gastric ulcers, irritable bowel syndrome, urinary
incontinence, atopic dermatitis, diabetes mellitus type 2, hypercholesterolaemia, thyroid disorders, menopausal
symptoms, various types of cancer (e.g. ovarian cancer and melanoma), various types of infections (e.g. HIV, influenza
and Hepatitis B), and acute trauma. Many cases involved the withholding of study data by manufacturers and
regulatory agencies or the active attempt by manufacturers to suppress publication. The ascertained effects of
reporting bias included the overestimation of efficacy and the underestimation of safety risks of interventions.
In conclusion, reporting bias is a widespread phenomenon in the medical literature. Mandatory prospective
registration of trials and public access to study data via results databases need to be introduced on a worldwide scale.
This will allow for an independent review of research data, help fulfil ethical obligations towards patients, and ensure a
basis for fully-informed decision making in the health care system.