Reporting of results among drug tests registered in ClinicalTrials.gov

Reporting of results among drug tests registered in ClinicalTrials.gov

Annals of Internal Medicine
Florence T. Bourgeois, Srinivas Murthy, Kenneth D. Mandl
2010

An analysis published in 2010 on Annals of Internal Medicine, carried out by three researchers from the Boston Children's Hospital and financed with public funds, describes the characteristics of the trials recorded on ClicalTrials.gov regarding the efficacy and safety of 5 classes of drugs and verifies whether the source of the funding was associated with the publication of favorable results for the drug. Among the 78.276 trials registered by 31.08.2009, those concerning 5 classes of drugs were selected: cholesterol lowering, antidepressants, antipsychotics, proton pump inhibitors, vasodilators. Of the 4.825 trials thus highlighted, 546 were included in the trial, those relating to efficacy and safety which began and ended between 01.01.2000 and 31.12.2006. For each trial selected, the study design, the funding source, the date of registration and publication and the final result were described. The main source of funding has been classified as industry, government agencies, non-profit or non-federal bodies (universities, hospitals, foundations). Of the 546 trials, 346 (63%) were funded by industry, 74 (14%) by government agencies and 126 (23%) by non-profit or non-federal bodies. Industry-funded trials are more likely to be phase 3 or 4 (88.7%; P <0.001), to use an active comparator drug (36.8%; P = 0.010), to be multicentric (89.0%; P <0.001), to enroll a greater number of participants (median sample size, 306 participants against 78 and 50 of the trials financed by other sources; P <0.001), to enroll at least 75% of the expected participants (84,9%; P <0.001). In contrast, only trials funded by government agencies included a significant number of children (37,8%; P <0.001). Of all the trials, only 362 (66,3%) published the results: 230 (66,5%) among those financed by industry, 41 (55,4%) by government agencies and 91 (72,2%) by non-profit or non-federal entities. Industry-funded trials reported a positive result in 85.4% of publications, compared to 50.0% of government trials and 71.9% of those funded by nonprofit or non-federal organizations (P <0.001). Among the latter, those in which there was an industry contribution, reported positive results more frequently than those without contributions (85.0% vs. 61.2%; P = 0.013). The rate of publication of the trials within 24 months from the end of the study, ranges from 32.4% for those financed by the industry to 56.2% for those financed by non-profit or non-federal bodies without industry contributions (P = 0.005). The authors point out that it was not always possible to confirm whether a study had been published and this could have led to some classification errors. Furthermore, further information, which is not yet available, on the protocol and on the results of the trials in general could shed light on the factors underlying the link between the source of funding and the results. The authors close their article by stating that industry-funded trials are less likely to be published within 2 years of their completion and more likely to report positive results.

Source: http://www.annals.org/content/153/3/158.abstract