Background: Previously, we showed that sex-specific complete blood count (CBC) risk scores strongly predicted risk of all-cause mortality in multiple sets of general medical patients. This study evaluated the CBC risk score in an independent, well-studied international primary risk population of lower-risk individuals initially free from cardiovascular (CV) disease.
Design: Observational secondary analysis of a randomized trial population.
Methods: The previously derived and validated CBC score was evaluated for association with all-cause mortality among CV disease-free females (n = 6568) and males (n = 10,629) enrolled for up to 5 years in the Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial. Associations of the CBC score with CV mortality and with major CV disease were also tested.
Results: The CBC score predicted all-cause mortality, with univariable hazard ratio (HR) 4.83 (95% CI 3.70-6.31) for the third CBC score tertile vs. the first tertile, and HR 2.31 (CI 1.75-3.05) for the second tertile (p trend < 0.001). The CBC score retained significance after adjustment: HR 1.97 (CI 1.46-2.67) and 1.51 (CI 1.13-2.00) for tertiles 3 and 2 vs. 1, respectively (p trend < 0.001). The CBC score also predicted CV mortality (p trend = 0.025) and the primary JUPITER endpoint (p trend = 0.015). c-statistics for mortality were 0.729 among all, and 0.722 and 0.750 for females and males, respectively.
Conclusions: The CBC risk score was strongly associated with all-cause mortality among JUPITER trial participants and had good discrimination. It also predicted CV-specific outcomes. This CBC score may be useful in identifying cardiac disease-free individuals at increased risk of mortality.
Keywords: CBC; clinical decision rule; clinical prediction rule; red cell distribution width.
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