Dear Editor,
Dehghani et al. have provided remarkable results in their recent article in your esteemed journal; A Step-by-Step Framework on Discrete Events Simulation in Emergency Department; A Systematic Review, Volume 5, Issue 2 [1]. Given that systematic review studies have the highest level of evidence and play an important role in evidence-based decision making in healthcare [2], it is necessary to explain and clarify a few points about this mentioned study.

1. The first point is about the title, according to the explanation given in the materials and methods section, this study is not a systematic review, and only the first phase of this review is systematic.
2. The second point is about the abstract, where the number of articles has been included in the method section and it is wrong, because the number of include studies is a part of the results of a systematic review. Of course, this objection is correctly stated in the results section in the full text of the article.
3. The third point is related to the number of searched databases. In a systematic review, all existing studies in one area should be identified. When we search for only two data bases, we lose a lot of relevant studies. With a simple search on the other databases, you can find quite relevant articles that are not included in this study. Examples of such studies are Kozlowski et al., [3], Bair et al., [4], and Hoerning et al., [5].
4. The fourth point is about the search period. Is there a compelling reason to choose this interval? If there is such a reason, authors should mention it in the article.
5. The fifth point is about the quality assessment of included studies. There is nothing about the quality assessment of included studies and used checklist. While, quality assessment/appraisal is one of the main steps in a systematic review.
6. The sixth point is about the qualitative method. The authors have stated that they have used qualitative review. What qualitative method is used for data analysis? The only mention of qualitative review is not how to analyze the results. The expression "qualitative review" does not indicate how to analyze the results.
7. The seventh point is about the number of duplicate sentences in the text of the article. There are examples of these cases like lines 23 and 25 about time limitation, or description of Figure one at the end of review method and as well as at the beginning of the results at the beginning and end of the results section.
8. The eighth point is about importing the records to EndNote. Interestingly, the researchers first read the articles on the basis of the title and abstract, and then imported the records to EndNote and removed the duplicates.
9. The ninth point is that no finding has been made for the second phase of the study in the results section.

Notwithstanding the good results of this study, it seems that the method of study is not clear and does not have the transparency. There are many pitfalls in the methodology and study results. It is recommended that authors write the report in accordance with the PRISMA Protocol in order to prevent such problems [6, 7]. This will make the study process transparent and preventing errors during reporting the results. The existence of such clear mistakes will also affect the credibility of the authors, journals and the publishers. It is advisable for respected referees of journals to apply stronger strategies when review such studies to avoid problems like this.

Conflict of Interest: None declared.