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Errors in Assessing Race and Ethnicity in Clinical Trial Enrollment
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Errors in Assessing Race and Ethnicity in Clinical Trial Enrollment Keywords: Systematic review-Randomized-Source bias-Grey literatureTrials-African Americans-Hepatitis
Copyright ª 2016 by the National Medical Association. Published by Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.jnma.2016.08.004
To the Editors, read with interest Wilder et al’s (2016) article, “A Systematic Review of Race and Ethnicity in Hepatitis C Clinical Trial Enrollment” which aimed to review the participation of African Americans in HCV trials from 2000 to 2011.1 Although the authors recognize the importance of assessing race and ethnicity in clinical trial enrollment, the methods that they used were not comprehensive. A major problem I noticed is using only PubMed in the article search. By using only one database in this systematic review, the authors introduced selection bias. Selection bias may be introduced if the authors of a review rely on the wrong databases or only a few databases; this practice results in the selection of studies that are not representative of the general literature. Ideally a reviewer would engage in a selection of appropriate and multiple databases to minimize the risk of selection bias. I used the search strategy provided by the authors on the EMBASE database and this yielded 39,212 articles from the initial search. This search result starkly compares 588 original search results yielded in the original search using PubMed and illustrates the need for inclusion of multiple databases. Secondly, when I conducted the search in PubMed with the Mesh terms and supplementary concepts provided in the original review I did not get similar results as the authors. The search only resulted in 534 studies, not the 588 indicated in the article. Generally as time progresses more articles are added to the database related to subject
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matter, however in this particular case the search yielded significantly less results than the original search. To determine whether or not this review complied with the standard criteria for literature reviews I used the PRISMA guidelines. The PRISMA checklist is a 27-item instrument, which is used to help authors improve the reporting of systematic reviews and meta-analyses.2 The final issue that I noticed was it is not clearly indicated in the text how the number of included articles decreased from 123 to 54. In Figure 1 of the text there is no transitional arrow that indicates this decrease in articles; this leaves the reader with the task of making an assumption about the methodology and reasoning of this step of the methods. This failure to justify the reason for the decrease in studies does not comply with the seventeenth criterion of the PRISMA checklist. When assessing important information related to participation in clinical trials it is important to choose representative studies in a method that is understandable and replicable. Kristopher Myers, M.P.H. Olatokunbo Osibogun, M.P.H. Purnima Madhivanan, Ph.D. Department of Epidemiology, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA E-mail: Kmyer016@fiu.edu
REFERENCES 1. Wilder, J., Saraswathula, A., Hasselblad, V., & Muir, A. (Feb 2016). A systematic review of race and ethnicity in hepatitis C clinical trial enrollment. J Natl Med Assoc, 108(1), 24e29. 2. Moher, D., Liberati, A., Tetzlaff, J., & Altman, D. G. (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann Intern Med, 151(4), 264e269.
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION
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Errors in Assessing Race and Ethnicity in Clinical Trial Enrollment Keywords: Systematic review-Randomized-Source bias-Grey literatureTrials-African Americans-Hepatitis
Copyright ª 2016 by the National Medical Association. Published by Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.jnma.2016.08.004
To the Editors, read with interest Wilder et al’s (2016) article, “A Systematic Review of Race and Ethnicity in Hepatitis C Clinical Trial Enrollment” which aimed to review the participation of African Americans in HCV trials from 2000 to 2011.1 Although the authors recognize the importance of assessing race and ethnicity in clinical trial enrollment, the methods that they used were not comprehensive. A major problem I noticed is using only PubMed in the article search. By using only one database in this systematic review, the authors introduced selection bias. Selection bias may be introduced if the authors of a review rely on the wrong databases or only a few databases; this practice results in the selection of studies that are not representative of the general literature. Ideally a reviewer would engage in a selection of appropriate and multiple databases to minimize the risk of selection bias. I used the search strategy provided by the authors on the EMBASE database and this yielded 39,212 articles from the initial search. This search result starkly compares 588 original search results yielded in the original search using PubMed and illustrates the need for inclusion of multiple databases. Secondly, when I conducted the search in PubMed with the Mesh terms and supplementary concepts provided in the original review I did not get similar results as the authors. The search only resulted in 534 studies, not the 588 indicated in the article. Generally as time progresses more articles are added to the database related to subject
I
194
VOL. 108, NO 4, WINTER 2016
matter, however in this particular case the search yielded significantly less results than the original search. To determine whether or not this review complied with the standard criteria for literature reviews I used the PRISMA guidelines. The PRISMA checklist is a 27-item instrument, which is used to help authors improve the reporting of systematic reviews and meta-analyses.2 The final issue that I noticed was it is not clearly indicated in the text how the number of included articles decreased from 123 to 54. In Figure 1 of the text there is no transitional arrow that indicates this decrease in articles; this leaves the reader with the task of making an assumption about the methodology and reasoning of this step of the methods. This failure to justify the reason for the decrease in studies does not comply with the seventeenth criterion of the PRISMA checklist. When assessing important information related to participation in clinical trials it is important to choose representative studies in a method that is understandable and replicable. Kristopher Myers, M.P.H. Olatokunbo Osibogun, M.P.H. Purnima Madhivanan, Ph.D. Department of Epidemiology, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, FL, 33199, USA E-mail: Kmyer016@fiu.edu
REFERENCES 1. Wilder, J., Saraswathula, A., Hasselblad, V., & Muir, A. (Feb 2016). A systematic review of race and ethnicity in hepatitis C clinical trial enrollment. J Natl Med Assoc, 108(1), 24e29. 2. Moher, D., Liberati, A., Tetzlaff, J., & Altman, D. G. (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann Intern Med, 151(4), 264e269.
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION