Table 3.

Items that will be collected using the data extraction form

Parameter	Information for extraction
Population	Participant inclusion and exclusion criteria Demographic characteristics (age, sex and ethnicity distributions) Sample size
Exposure	Definition and identification of individuals with the risk factor(s) of interest Number of individuals with the risk factor(s) of interest
Comparator	Definition and identification of individuals without the risk factor(s) of interest Number of individuals without the risk factor(s) of interest
Outcome	Definition and identification of mental illness outcome(s) Number of individuals in exposed and comparison group with the outcome
Study characteristics	Bibliographic information (authors, journal, publication year, volume, page numbers and doi) Study design Study setting Study sampling frame Methods of participant recruitment Aims and objectives
Study results	Unadjusted and fully adjusted effect estimates for the association between risk factors and mental illness Confounders measured and adjusted for analysis