Predictive Value of Life's Crucial 9 for Cardiovascular and All-Cause Mortality: A Prospective Cohort Study From the NHANES 2007 to 2018

Abstract

Background: The predictive value of Life's Crucial 9 (LC9), a recently proposed cardiovascular health risk score combining psychological health and Life's Essential 8 (LE8), remains unclear.

Methods and results: In this cohort study, we included 16 290 adults without cardiovascular disease from the 2007 to 2018 cycles of NHANES (National Health and Nutrition Examination Survey). The LC9 was the mean of the LE8 score and the depression score, which represented a dimension of psychological health. The study outcomes were cardiovascular and all-cause mortality. Cox proportional hazard models were fitted to estimate the association of LC9 and LE8 scores with outcomes. The differences in Harrell's concordance index, net reclassification improvement index, and integrated discrimination improvement were calculated to assess the predictive ability of the depression score in addition to the LE8 score. During a median follow-up of 7.08 years, 879 (5.40%) participants died, and 242 (1.49%) died from cardiovascular disease. The adjusted hazard ratio (HR) of per LE8 10-score increase for cardiovascular mortality was 0.80 (95% CI, 0.72-0.88; P<0.001) and the adjusted HR of per LC9 10-score increase was 0.77 (95% CI, 0.69-0.86; P<0.001). Adding the depression score to the LE8 score, the improvement in concordance index for cardiovascular mortality was 0.001 (95% CI, -0.001 to 0.003; P=0.30), the net reclassification improvement index was 10.6% (95% CI, -7.6% to 18.9%; P=0.073), and the IDI was 0.002 (95% CI, 0.000-0.007; P=0.033). The results for all-cause mortality showed similar patterns.

Conclusions: Compared with the LE8, the improvement in the predictive value of LC9 was negligible. It may not be necessary to add a depression score to the current cardiovascular health score.

Keywords: Life's crucial 9; NHANES; all‐cause mortality; cardiovascular mortality; predictive value.

Figure 1. Flow chart of the sample selection.

NHANES indicates National Health and Nutrition Examination Survey.

Figure 2. Subgroup analysis for the associations between pre Life's Crucial 9 10‐score increase and cardiovascular mortality.

The models were adjusted for age, sex, race or ethnicity, education level, marital status, and the ratio of family income to poverty. We employed the age as a categorial variable when testing the interaction between age and Life's Crucial 9 score and as a continuous variable when using age as a covariate. GED indicates general educational development; and HR, hazard ratio.

Figure 3. Subgroup analysis for the associations between pre Life's Crucial 9 10‐score increase and all‐cause mortality.

The models were adjusted for age, sex, race or ethnicity, education level, marital status, and the ratio of family income to poverty. We employed the age as a categorial variable when testing the interaction between age and Life's Crucial 9 score and as a continuous variable when using age as a covariate. GED indicates general educational development; and HR, hazard ratio.