Study of Cardiovascular Health Outcomes in the Era of Claims Data: The XXXX .

@entity1 @entity712 @entity64 @entity583 @entity65
BACKGROUND: Increasingly, the diagnostic codes from administrative claims data are being used as clinical outcomes. METHODS AND RESULTS: Data from the @entity65 ( @entity65 ) 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 @entity583 ( @entity583 ), @entity64 , and @entity712 were defined in 3 ways: the @entity65 adjudicated event ( @entity65 [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 @entity583 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 @entity583 , the incidence was 14.9 events per 1000 @entity1 -years for @entity65 [adj] @entity583 , 8.6 for CMS[1st] @entity583 , and 12.2 for CMS[any] @entity583 . In general, @entity65 risk factor associations were similar across the 3 methods of defining events. Indeed, traditional @entity65 risk factors were also associated with all first hospitalizations not resulting from an @entity583 . 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.
