Reporting of informed consent and ethics committee approval in clinical trials

To determine whether journals have improved their disclosure of ethical protections in clinical trials.

Comparison of clinical trials published before and after 1997 (July 1995 to December 1996 and January 1998 to June 1999) in Annals of Internal Medicine, BMJ, JAMA, The Lancet, and The New England Journal of Medicine. Sixty articles per journal per period were randomly selected and assessed for rate of reporting on informed consent and on ethics committee approval.

Informed consent was not described in 79 articles (26%) published before 1997 vs 53 (18%) published after 1997 (P =.01), and ethics committee approval was not mentioned in 93 (31%) before 1997 vs 54 (18%) after 1997 (P<.001). Neither protection was described in 48 articles (16%) published before 1997 vs 28 (9%) after 1997 (P =.01). In subgroup analyses, those journals with the worst initial rates generally improved the most. BMJ did not describe informed consent in 25 articles (42%) before 1997 vs 15 (25%) after 1997 (P =.05), and JAMA did not describe ethics committee approval in 25 (42%) before 1997 vs 13 (22%) after 1997 (P =.02). BMJ, JAMA, and Annals had the lowest initial rates of reporting on both protections in the same article, with 25 (42%), 32 (53%), and 34 (57%), respectively, but improved markedly to 38 (63%), 43 (72%), and 45 (75%) (P =.02,.04, and.03, respectively).

Major medical journals have improved their reporting on informed consent and ethics committee approval; however, 9% of studies still report neither.