. Author manuscript; available in PMC: 2020 Dec 4.

Published in final edited form as: JAMA Cardiol. 2020 Feb 1;5(2):147–155. doi: 10.1001/jamacardio.2019.4528

Table 4.

Risk Analysis for Changes in CPC Counts During Exercise for Composite Event Rate of Cardiovascular Death and Myocardial Infarction

Variable	C Statistic (95% CI)	Change in C Statistic (95% CI)	Continuous NRI (95% CI)	IDI (95% CI)
Model^a	0.72 (0.62–0.80)	NA	NA	NA
Model plus CD34⁺ change	0.76 (0.69–0.86)	0.04 (0.01–0.11)	0.50 (0.21–0.71)	0.03 (0.01–0.08)
Model plus CD34⁺/CXCR4⁺ change	0.77 (0.71–0.91)	0.06 (0.02–0.13)	0.54 (0.28–0.79)	0.04 (0.01–0.11)

Abbreviations: CPC, circulating progenitor cell; IDI, integrative discrimination improvement; NA, not applicable; NRI, net reclassification index.

The model includes age; sex; race; smoking history; body mass index (calculated as weight in kilograms divided by height in meters squared); history of heart failure, hypertension, dyslipidemia, and diabetes; baseline CD34⁺ levels; baseline CXCR4⁺ levels; and positive stress test results.