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Healthy Skepticism Library item: 6860

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.


Publication type: Journal Article

Kjaergard LL, Nikolova D, Gluud C.
Randomized clinical trials in hepatology: predictors of quality.
Hepatology 1999 Nov; 30:(5):1134-8


Evidence shows that the quality of randomized clinical trials (RCTs) affects estimates of intervention efficacy, which is significantly exaggerated in low-quality trials. The present study examines the quality of all 235 RCTs published in HEPATOLOGY from the initiation in 1981 through August 1998. Quality was assessed by means of a validated 5-point scale and separate quality components associated with empirical evidence of bias. Only 26% of all RCTs reported sample size calculations, 52% adequate generation of the allocation sequence, 34% adequate allocation concealment and 34% double-blinding. The median quality score of all trials was 3 points (range, 1-5 points). Multiple logistic regression analysis explored the association between quality and therapeutic areas, number of centers, external funding, year of publication, and country of origin. High-quality trials were most likely to investigate portal hypertension (odds ratio [OR]: 2.4; 95% CI: 1.1-5.5; P =.03), be multicentered (OR: 3.4; 95% CI: 1.3-8.9; P =.01), sponsored by public organizations (OR: 4.2; 95% CI: 2.1-8.6; P =.0001), or the drug and device industry (OR: 4.7; 95% CI: 2.2-10.2; P =.0001) compared with other therapeutic areas, single-center trials, and trials with no external funding. Quality did not improve with time and was not associated with country of origin. The main conclusions are that the quality of RCTs in HEPATOLOGY needs improvement and that the probability of high quality increased with the number of centers involved and external funding.

*systematic review/Hepatology/quality of information/ clinical trials/ drug company sponsored research/SPONSORSHIP: RESEARCH


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Cases of wilful misrepresentation are a rarity in medical advertising. For every advertisement in which nonexistent doctors are called on to testify or deliberately irrelevant references are bunched up in [fine print], you will find a hundred or more whose greatest offenses are unquestioning enthusiasm and the skill to communicate it.

The best defence the physician can muster against this kind of advertising is a healthy skepticism and a willingness, not always apparent in the past, to do his homework. He must cultivate a flair for spotting the logical loophole, the invalid clinical trial, the unreliable or meaningless testimonial, the unneeded improvement and the unlikely claim. Above all, he must develop greater resistance to the lure of the fashionable and the new.
- Pierre R. Garai (advertising executive) 1963