Two of the researchers independently applied the ACROBAT-NRSI process to 37 papers included in two widely cited systematic reviews of non-randomized studies of the relationship between the use of thiazolidinediones (drugs used to treat diabetes, such as rosiglitazone and pioglitazone) and cyclooxygenase-2 (COX-2) inhibitors (nonsteroidal anti-inflammatory drugs [NSAIDs] such as ibuprofen) and major cardiovascular events (heart attack [myocardial infarction] and heart failure). Here, PTGS2 is linked to diabetes mellitus.