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

Circulation. 2016 Jan 12;133(2):156-64. doi: 10.1161/CIRCULATIONAHA.115.018610. Epub 2015 Nov 4.


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: epidemiology; heart failure; incidence; myocardial infarction; stroke.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Blood Glucose / analysis
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / epidemiology*
  • Cardiovascular Diseases / therapy
  • Female
  • Follow-Up Studies
  • Health Surveys
  • Hospitalization / statistics & numerical data
  • Hospitals, Veterans / statistics & numerical data
  • Humans
  • Insurance Claim Review
  • International Classification of Diseases
  • Lipids / blood
  • Male
  • Managed Care Programs / statistics & numerical data
  • Medicare / statistics & numerical data*
  • Risk Factors
  • Sampling Studies
  • Treatment Outcome
  • United States / epidemiology


  • Blood Glucose
  • Lipids