Validation of Diagnostic and Procedural Codes for Identification of Acute Cardiovascular Events in US Veterans with Rheumatoid Arthritis

OBJECTIVE: To assess the accuracy of International Classification of Diseases, Ninth Revision, and Current Procedural Terminology codes for identifying cardiovascular (CV) events (myocardial infarction [MI], stroke, coronary artery bypass graft [CABG], and percutaneous coronary intervention [PCI]) in enrollees of the Veterans Affairs Rheumatoid Arthritis (VARA) registry. DESIGN: We performed a validation study from VARA enrollment until 6/1/2010 to compare the accuracy of CV events in those with and without CV-event coding in inpatient and outpatient records to evaluate for CV events +/− 3 months of the coding. The positive predictive value (PPV) was calculated, and codes with a PPV ≥50% were included in a composite coding algorithm. RESULTS: We evaluated 107 individuals for 21 CV-event codes and 60 individuals without CV-event coding. The PPV varied between 0–100%. Composite coding algorithms’ PPV ranged from 70–100%. CONCLUSIONS: Validation of these algorithms allows for identification of acute CV events with known accuracy. The sensitivity and PPV of coding algorithms for CABG and PCI exceed that of stroke and MI.