We read with great interest the publication titled, “Use of Simulated Patients in Disaster Medicine Training: A Systematic Review,” by Pier Luigi Ingrassia et al., ^{Reference Ingrassia, Pigozzi and Bono1} in the journal, Disaster Medicine and Public Health Preparedness. Although the authors have stated that they reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, some items have not been well reported. Therefore, the aim of this letter is to present methodological issues about the search strategy and quality assessment of included studies.

First, the number of databases searched for literature has been limited to PubMed, the search strategy seems simple, and the only language of interest is English. However, other databases could be searched. This may increase the likelihood of a search bias, that is, missing some studies, language bias, and publication bias. Searching a single database can reduce sensitivity to as low as 66%. Generally, a systematic review must search major medical databases, including PubMed, Scopus, Web of Science, EMBASE, and Cochrane Library. ^{Reference Aromataris and Riitano2,Reference Gholizadeh, Amir-Behghadami and Janati3} Also, according to the PRISMA statement, it is suggested that the search strategy be devised at least for PubMed and replicated for the other electronic databases. ^{Reference Moher, Liberati, Tetzlaff and Altman4}

Second, despite not making any qualitative evaluations possible in this study, we observed that none of the studies included in this review have been qualitatively evaluated. Analyzing and interpreting preliminary studies in a systematic review require qualitative assessment and bias sensitivity assessment because poor quality studies can affect the quality of the results and distort the results of the studies. ^{Reference Amir Behghadami and Janati5,Reference Janati, Amir-Behghadami and Arab-Zozani6} The included studies should be evaluated with tools that are appropriate to the type of study. Determining the type of study in the inclusion criteria will be helpful. If a wide range of types of publications were considered, the authors could have used the JBI Critical Appraisal Checklists because the JBI Scientific Committee had designed specific checklists for all types of studies. ^{Reference Behghadami and Janati7,Reference Porritt, Gomersall and Lockwood8}

Systematic reviews are different and more valid than other literature reviews because they provide the best evidence available to researchers. This systematic review should provide an explicit and repeatable methodology. Therefore, it is recommended that physicians, researchers, and journals follow the PRISMA guidelines because they improve the quality of reports of such studies.