Abstract
Background: Health literacy has predicted mortality in heart failure. However, the role of cognitive functioning in this relationship has not been evaluated. We hypothesized that health literacy would predict all-cause mortality but that cognitive functioning would modify the relationship between health literacy and mortality in heart failure.
Objective: The aim of this study was to examine the association between health literacy, cognitive functioning, and mortality in patients with heart failure.
Methods: This secondary analysis of a larger study included 298 patients with heart failure with reduced ejection fraction (trial identifier: NCT01461629). Health literacy was evaluated using the Rapid Estimate of Adult Literacy in Medicine (REALM) and Medical Term Recognition Test (METER), and cognitive functioning was evaluated using the Modified Mini-Mental Status Examination (3MS). Cox proportional hazards regression was used with time-until-death as the dependent variable.
Results: After controlling for age, sex, and race, neither METER nor REALM scores predicted mortality in heart failure (Ps >= .37). However, 3MS predicted mortality in models using the METER ([DELTA][chi]2 = 9.20, P < .01; B = -.07; hazard ratio, 0.94 [95% confidence interval, 0.89-0.98]; P < .01) and REALM ([DELTA][chi]2 = 9.77, P < .01; B = -0.07; hazard ratio, 0.94 [95% confidence interval, 0.90-0.97]; P < .01). Furthermore, adding the 3MS improved model fit.
Conclusions: Cognitive functioning predicted mortality in heart failure better than health literacy. Results suggest the need to further evaluate the contribution of cognitive functioning to increased risk of mortality in those with heart failure.