*2.5. Quality Assessment*

The 'Standard quality assessment criteria for evaluating primary research papers from a variety of fields' [45] was used to assess the methodological quality of the included studies. The checklist consists of 14 items which were given a certain score depending on whether or not the specific criterion was met ("no" = 0, "partial" = 1, "yes" = 2). Depending on the study design, some items were not applicable and were therefore scored as 'not applicable (N/A)' and excluded from the calculation of the total score. The total sum was calculated by summing the total number of "yes" multiplied by 2 and the total number of "partials" multiplied by 1. The total possible sum was calculated as follows: 28 − (number of 'N/A' × 2). Lastly, the summary score was calculated by dividing the total sum by the total possible sum.
