Because most studies in this field are cross-sectional studies. The AXIS tool (to assess the quality of cross-sectional studies) is used for studies quality assessment (38). However, in this study, given that our subject is very specialized, to evaluate the quality of articles, the expert team designs 10 questions according to the characteristics of the study and tools in the field of environmental sciences, including the criteria designed by Bilotta et al., (39-41). The questions are designed to cover Selectionselection and performance bias (questions 3, 6), Assessment; assessment bias (questions 1, 2, 4, 5), Bias; bias linked to clarity and publication bias (questions 8, 10),; and Detectiondetection bias (questions 7, 9) as much as possible. In table 2, if the answer is "Yes", it is indicated thatindicating low bias and high quality. Therefore, a score equal to 1 is assigned to it. If the answer is "No", it indicates high bias and low quality, then it is given a score equal to 0. If questionquestions do not allow us to reach a clear Yes/Noyes/no answer to these questions, we will classify the answer as "Unclear", Thereforetherefore, it should be reviewed by team members before scoring. Finally, if the answer is "Unclear", it indicates medium bias and medium quality. Therefore, therefore, a score equal to 0.5 is assigned to it.
Before screening all articles (pre-screening), to evaluate include and exclude criteria, randomly, 10% of the articles (minimum 50) will be screened by two reviewers and use Kappa tests to evaluate. If the kappaKappa score of 0.6≤scores, our include and exclude criteria are acceptable;, otherwise, including and excluding criteria will be modified, and the process will be repeated until an acceptable Kappa score is achieved.
If our search strategy fails to retrieve test list articles. Wethen we need to modify search strategy again, until it retrieves all test list articles.