Fig. 2From: Adding non-randomised studies to a Cochrane review brings complementary information for healthcare stakeholders: an augmented systematic review and meta-analysisRisk of bias by study design. Low risk of bias; Unclear risk of bias; High risk of bias; Not applicable; RCT: randomised controlled trial; QRCT: quasi-randomised controlled trial; CBA*: controlled before-after study (with at least two intervention and two control sites); CBA: controlled before-after study; ITS: interrupted-times-series study; BA: before-after study (without external control group); XS: cross-sectional study (with concurrent measurement of intervention exposure and outcomes)Back to article page