Table 2.

Positive predictive value of heart failure diagnosis codes for validated events according to encounter type

EventPatients, nSampled, nValidated events, nPPV (95% CI), %
Principal diagnosis hospitalization225534992 (82 to 98)
Secondary diagnosis hospitalization12361976332 (26 to 39)
Two outpatient encounters403634470 (57 to 81)
  • Persons with at least one potential heart failure event during follow were sampled according to the encounter type of the first potential event. Participants with prevalent heart failure at baseline were ineligible to have outpatient heart failure events during follow up. International Classification of Disease, Ninth Revision, codes were used to identify potential heart failure events: 402. × 1, 404. × 1, 425.4, 428. PPV, positive predictive value; 95% CI, 95% confidence interval.