Relative risk of acute myocardial infarction and stroke in rosiglitazone users compared with pioglitazone users. AMI, acute myocardial infarction; IV, inverse variance. Red bars, percentage of items in the RTI item bank indicating high risk of bias; yellow bars, percentage of items at unclear risk of bias. Items with low risk of bias not shown. Denominators indicate the number of items evaluated for each study.