Differential Citation Rates of Major Cardiovascular Clinical Trials According to Source of Funding

Abstract

Background-Prior work indicates that therapeutic trials funded by for-profit organizations are more likely to report positive findings than trials funded by not-for-profit organizations. What impact, if any, funding source has on subsequent dissemination of trial data is uncertain. To address this issue, we used the number of citations per publication per year to assess differences in trial dissemination according to funding source. Overall, the median number of citations per publication per year was 46 for trials funded exclusively by for-profit organizations, 37 for trials jointly funded, and 29 for trials funded by not-for-profit organizations (Pϭ0.0007). Higher citation rates for trials funded by for-profit organizations were consistently observed in analyses stratified by journal and various trial design features and were most striking when the new intervention was favored over the standard of care; in this subgroup, the median number of citations per publication per year was 52 for trials funded by for-profit organizations compared with 25 for trials funded by not-for-profit organizations (Pϭ0.0006).In marked contrast, in analyses limited to trials in which the new intervention was significantly worse than the standard of care, an inverse pattern was observed with fewer citations per publication per year for trials funded by for-profit organizations compared with not-for-profit organizations (33 versus 41; Pϭ0.048). Higher citation rates were observed for industry-funded trials than for federally funded trials even when the trials dealt with similar issues and were published back-to-back in the same journal. Conclusions-Dissemination of clinical trial results is important for clinical practice but appears to be biased in favor of for-profit entities. Consideration should be given to more extensive promotion of clinical trial results that are funded by not-for-profit organizations.

Declaraciones de financiación en las revistas biomédicas: estudio descriptivo de cuatro publicaciones españolas

“…Al comparar los resultados obtenidos con los disponibles en la literatura se observa que la frecuencia de declaración de financiación en las revistas biomédicas españolas se encuentra considerablemente por debajo del 89% declarado en los ensayos clíni-cos aleatorizados publicados en 5 revistas de medicina general 11 , del 78% comunicado en los ensayos clínicos sobre cáncer 12 , del 80% en los artículos de investigación sobre el virus de la inmunodeficiencia humana 13 y del 67% en los artículos de las 15 revistas líderes de gastroenterología 14 . En cuanto a las fuentes de financiación declaradas, el 36,5% de financiación privada identificada (37% en el caso de los artículos originales) se encuentra por debajo del 66% declarado en una muestra de 100 ensayos clínicos publicados en 5 revistas internacionales, generalistas y de elevado factor de impacto (Annals of Internal Medicine, Bristish Medical Journal, JAMA, TheLancet, NEJM) 16 y del 45% declarado en los estudios comparativos directos en el área cardiovascular publicados en JAMA, The Lancet y NEJM 17 , pero es similar al 38,3% y el 34,6% de financiación por parte de la industria declarado en los artículos originales publicados en NEJM y JAMA respectivamente 18 .…”

Intérêts et conflits d’intérêts: le point de vue d’un expert

“…Kulkarni et al [32] montrent que les études positives financées par l'industrie ont un taux annuel de citation de 25,7, alors qu'une étude positive non financée par l'industrie n'a qu'un taux de 2,5. Le travail de Conen et al [17] trouve également une différence très significative des taux de citations : le taux de citation annuel pour les études financées par l'industrie est deux fois plus élevé que pour les autres études (52 contre 25), lorsque le résultat de l'étude est favorable au nouveau médicament ; O N C O L O G I E le résultat est inverse dans la situation inverse : les études négatives financées par l'industrie sont nettement moins citées que celles financées par des institutions non commerciales. Enfin, ces auteurs ont trouvé trois exemples de diffé-rence nette de taux de citation pour des études sur le même sujet publiées dans le même volume du même journal, celle financée par l'industrie étant nettement plus citée que l'autre.…”

Children’s presence in research. A review of online registers

“…Registers are an important source of information not only for healthcare professionals but also for funding agencies when decisions have to be made regarding funding allocations as well as anyone interested in participating in a trial. Registers have an important role in preventing trial duplication (as opposed to replication) and, therefore, in avoiding any potential waste of resources and effort [1,2], but they are also invaluable to researchers conducting systematic reviews and to professionals compiling guidelines, since they are the only means of tracking research results, whether published or not [3,4]. Research that has negative or inconclusive results, in fact, often does not get published, despite the ethical imperative to provide a public record of such research [5,6].…”