Table 3.

Risk of bias assessment for randomized controlled trials

^aIn a cluster randomized trial, there are other domains to consider for risk of bias, including (1) recruitment bias; (2) baseline imbalance; (3) loss of clusters; (4) incorrect analysis; and (5) comparability. We judged Curtis 2011 [22] to be at high risk due to loss of clusters, incorrect analysis (due to lack of adjustment for clustering effects), and non-comparability between hospitals. Green = low risk of bias, Yellow = unclear risk of bias, Red = high risk of bias