EVALUATING THE QUALITY OF ARTICLES PUBLISHED IN JOURNAL SUPPLEMENTS COMPARED WITH THE QUALITY OF THOSE PUBLISHED IN THE PARENT JOURNAL

Objectives.-To determine the relationship between the quality of artic les and whether they were published in a supplement or in the parent j ournal. Data Sources and Study Selection.-All randomized control trial s of drug therapies in adults published in the American Journal of Car diology, the American Journal of Medicine, and the American Heart Jour nal from January 1990 and obtained in November 1992 by means of a MEDL INE search. A total of 318 abstracts appeared to meet our inclusion cr iteria, and these articles were obtained and reviewed in further detai l. An additional 76 were excluded. Data Extraction.-Three reviewers wh o were ''blinded'' and thus unaware of supplement status independently assessed the quality of each of the remaining 242 articles according to a standard quality scoring system. Data Synthesis.-Overall, 67 (27. 7%) of the articles were published in journal supplements. Article qua lity scores ranged from 4.2% to 87.5%, with a mean (+/-SD) score of 37 .2%+/-13.1%. Quality scores were lower in articles published in journa l supplements than in those published in the parent journal (t[240]=2. 61, P=.01). The mean quality score for articles published in journal s upplements was 33.6%+/-12.8% compared with a score of 38.5%+/-13.1% fo r articles published in the parent journal. Supplement articles includ ed in their final analysis a smaller proportion of the patients initia lly randomized (t[75]=2.8, P=.007). Conclusion.-Our findings suggest t hat randomized control trials published in journal supplements are gen erally of inferior quality compared with articles published in the par ent journal. The review process surrounding the publication of journal supplements should be consistent with that of the parent journal.