Quality Assessment of Studies using Quantitative Methodology.

Note. Item description: A; question/objective sufficiently described, B; study design evident and appropriate (in addition to corresponding item in QUALSYST [26]: for 2 points (p), study primarily designed to assess prevalence), C; method of subject/comparison group selection described and appropriate, D; subject (and comparison group, if applicable) characteristics sufficiently described, E; response rate >90% = 2 p, 70–90% = 1 p, <70% = 0 p, F; reasons for nonresponse described AND non-responders described AND comparison of responders and non-responders  = 2 p, at least one of the criteria mentioned for F = 1 p, none of the criteria mentioned for F = 0 p, G; outcome measure(s) well defined and robust to measurement/misclassification bias, H; sample size appropriate (rule of thumb n>100 = 2 p, n>50–100 = 1 p and n<50 = 0 p), I; analytic methods described/justified and appropriate, J; estimate of variance reported for the main results, K; results reported in sufficient detail, L; conclusions supported by the results, Mod  =  moderate.
aFull information regarding scoring of item A, C, D, G, H, I, J, K, L, se corresponding item in QUALSYST [26]. Scoring of item B, E, F, see item description in note under table.
bRatio between total score for each study and maximum total score. Ratio <0.5 was assessed as low quality, 0.5–0.75 as moderate quality, and >0.75 as high quality.
cRatio between sum of item score and maximum item score. Ratio <0.5 was assessed as low quality, 0.5–0.75 as moderate quality, and >0.75 as high quality.