Incomplete Reporting of Recruitment Information in Clinical Trials of Biologic Agents for the Treatment of Rheumatoid Arthritis: A Review ISMAIL SIMSEK 1 AND YUSUF YAZICI 2 Objective. It is important to evaluate how a randomized controlled trial (RCT) sample was assembled from the general patient population in order to determine whether a patient differs from those who participated in the trial in a meaningful way. The aim of this study is to assess the adequacy of reporting of the recruitment process of rheumatoid arthritis (RA) patients participating in RCTs with biologic agents. Methods. We searched PubMed for all reports of RCTs involving etanercept, infliximab, adalimumab, golimumab, certolizumab, abatacept, tocilizumab, and rituximab in RA patients. Data recorded were eligibility fraction, enrollment fraction, recruitment fraction, and number of patients needed to be screened (NNS) in order to randomize 1 participant. Results. Of the 66 trials included in the analysis, 23 (35%) reported the number of individuals assessed by investigators for eligibility, and 18 (27%) reported the number eligible for participation. Of the studies that reported quantitative recruitment information, the median eligibility fraction was 80.6% (interquartile range [IQR] 71.8 –91.1%) and the median enrollment fraction was 100% (IQR 88.4 –100%). The median NNS was found to be 1.28 (IQR 1.18 –1.43). Conclusion. A substantial majority of RCTs conducted in RA patients with biologic agents did not provide sufficient information about the patient recruitment process, which makes assessments of external validity difficult. The rate of reporting of the recruitment process in this study was found to be lower as compared to similar studies conducted in different specialties. Introduction Randomized controlled trials (RCTs) are regarded as the gold standard for determining the effectiveness of medical interventions (1). As also seen in RCTs done for other diseases, RCTs conducted with biologic agents in rheuma- toid arthritis (RA) patients generally describe outcomes among participants with little consideration of whether the seen effects can be generalized to larger patient popu- lations who are frequently unlike those who participate in RCTs (2). Before applying the results of an RCT for treating an individual patient, a clinician must determine whether his or her patient differs from those who participated in the trial in a meaningful way. Therefore, it is important to evaluate how the RCT sample was assembled from the general patient population. The trial recruitment process can be described with qualitative and quantitative data, of which both can con- tribute important information about the generalizability. In addition to being part of the good practice for the design and conduct of trials, clear and sufficiently detailed report- ing of participant flow is important in order to assess the generalizability, relevance, and comparability of the trial results. The adequacy of reporting in RCTs has received in- creased attention during the past 2 decades and culmi- nated in the publication of a Consolidated Standards of Reporting Trials (CONSORT) statement in 1996 (3). The original CONSORT checklist focuses primarily on im- proved reporting of information related to the internal validity of an RCT. To enable better reporting of informa- tion regarding external validity, the revised template for the CONSORT flow diagram starts at the stage of asking 1 Ismail Simsek, MD: Gu ¨ lhane School of Medicine, An- kara, Turkey; 2 Yusuf Yazici, MD: New York University School of Medicine, New York University Hospital for Joint Diseases, New York. Dr. Simsek has received consultant fees, speaking fees, and/or honoraria (less than $10,000 each) from Abbott and Pfizer. Dr. Yazici has received consultant fees, speaking fees, and/or honoraria (less than $10,000 each) from BMS, Abbott, Genentech, Merck, and Pfizer. Address correspondence to Ismail Simsek, MD, GATA Ro- matoloji BD, 06018, Etlik, Ankara, Turkey. E-mail: drisimsek @gmail.com. Submitted for publication February 9, 2012; accepted in revised form April 20, 2012. Arthritis Care & Research Vol. 64, No. 10, October 2012, pp 1611–1616 DOI 10.1002/acr.21721 © 2012, American College of Rheumatology BRIEF REPORT 1611