Table 4.

Definitions used in the depression variable and evaluation instrument tools.

Study	Depression Variable	Measurement
Norouzi et al. [29]	-The authors define the variable as “depressive symptoms”. However, during the paper, they also use the term depression. -The sum scores can be interpreted as follows (Ahmadpanah et al., 2016): 0–6 points: no depression; 7–19 points: mild depression; 20–34 points: moderate depression; >34 points: severe depression.	-Montgomery-Åsberg Depression Rating Scale (MADRS)
Junge and Prinz [30]	-The authors define the variable as “depressive symptoms”. However, during the paper, they also use the term depression. -The questionnaire also included questions on frequency of intake of medication for depression.	-The Center for Epidemiologic Studies Depression Scale (CES-D)
Smith et al. [31]	-The authors define the variable as “depressive symptoms”. However, during the paper, they also use the term depression.	-The Center for Epidemiologic Studies Depression Scale (CES-D)
Olmedilla et al. [32]	-Depression	-DASS-21
Jensen et al. [33]	-The authors define the variable as “depressive symptoms”. However, during the paper, they also use the term depression. -A cutoff score of 16 to define a clinical, significant level of depression was used.	-The Center for Epidemiologic Studies Depression Scale (CES-D)
Wood et al. [34]	-Depression	-Qualitative research design using interpretative phenomenological -analysis (IPA)
Van Ramele et al. [35]	-Depression	-General Health Questionnaire (GHQ-12)
Sanders and Stevinson [36]	-The authors define the variable as “depressive symptoms”. -Total possible scores range from 0 to 18, with lower scores indicating greater depression.	-Short Depression-Happiness Scale (SDHS; Joseph, Linley, Harwood, Lewis, & McCollam, 2004).
Prinz et al. [37]	-Severity of depression symptoms -Depression	-The Center for Epidemiologic Studies Depression Scale (CES-D) -PHQ-2
Junge and Feddermann-Demont [38]	-The authors define the variable as “depressive symptoms”.	-The Center for Epidemiologic Studies Depression Scale (CES-D)
Gouttebarge et al. [39]	-Depression	-General Health Questionnaire