@article {6932, title = {Study of Cardiovascular Health Outcomes in the Era of Claims Data: The Cardiovascular Health Study.}, journal = {Circulation}, volume = {133}, year = {2016}, month = {2016 Jan 12}, pages = {156-64}, abstract = {

BACKGROUND: Increasingly, the diagnostic codes from administrative claims data are being used as clinical outcomes.

METHODS AND RESULTS: Data from the Cardiovascular Health Study (CHS) were used to compare event rates and risk factor associations between adjudicated hospitalized cardiovascular events and claims-based methods of defining events. The outcomes of myocardial infarction (MI), stroke, and heart failure were defined in 3 ways: the CHS adjudicated event (CHS[adj]), selected International Classification of Diseases, Ninth Edition diagnostic codes only in the primary position for Medicare claims data from the Center for Medicare \& Medicaid Services (CMS[1st]), and the same selected diagnostic codes in any position (CMS[any]). Conventional claims-based methods of defining events had high positive predictive values but low sensitivities. For instance, the positive predictive value of International Classification of Diseases, Ninth Edition code 410.x1 for a new acute MI in the first position was 90.6\%, but this code identified only 53.8\% of incident MIs. The observed event rates for CMS[1st] were low. For MI, the incidence was 14.9 events per 1000 person-years for CHS[adj] MI, 8.6 for CMS[1st] MI, and 12.2 for CMS[any] MI. In general, cardiovascular disease risk factor associations were similar across the 3 methods of defining events. Indeed, traditional cardiovascular disease risk factors were also associated with all first hospitalizations not resulting from an MI.

CONCLUSIONS: The use of diagnostic codes from claims data as clinical events, especially when restricted to primary diagnoses, leads to an underestimation of event rates. Additionally, claims-based events data represent a composite end point that includes the outcome of interest and selected (misclassified) nonevent hospitalizations.

}, keywords = {Blood Glucose, Cardiovascular Diseases, Female, Follow-Up Studies, Health Surveys, Hospitalization, Hospitals, Veterans, Humans, Insurance Claim Review, International Classification of Diseases, Lipids, Male, Managed Care Programs, Medicare, Risk Factors, Sampling Studies, Treatment Outcome, United States}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.115.018610}, author = {Psaty, Bruce M and Delaney, Joseph A and Arnold, Alice M and Curtis, Lesley H and Fitzpatrick, Annette L and Heckbert, Susan R and McKnight, Barbara and Ives, Diane and Gottdiener, John S and Kuller, Lewis H and Longstreth, W T} }