Fig. 1

Quality assessment of the studies. Checklist for assessing the quality of quantitative studies. 1 Question / objective sufficiently described?, 2 Study design evident and appropriate?, 3 Method of subject/comparison group selection or source of information/input variables described and appropriate?, 4 Subject (and comparison group, if applicable) characteristics sufficiently described?, 5 Sample size appropriate?, 6 Analytic methods described/justified and appropriate?, 7 Some estimate of variance is reported for the main results?, 8 Controlled for confounding?, 9 Results reported in sufficient detail?, 10 Conclusions supported by the results?. Checklist for assessing the quality of qualitative studies. 1 Question / objective sufficiently described?, 2 Study design evident and appropriate?, 3 Context for the study clear? 4 Connection to a theoretical framework / wider body of knowledge?, 5 Sampling strategy described, relevant and justified?, 6 Data collection methods clearly described and systematic?, 7 Data analysis clearly described and systematic?, 8 Use of verification procedure(s) to establish credibility?, 9 Conclusions supported by the results?, 10 Reflexivity of the account?