Correlation between health literacy and utility-based health-related quality of life scores in patients undergoing cardiac rehabilitation: a multicenter clinical study

Health literacy (HL) is correlated with the risk of mortality and readmission during cardiac rehabilitation. However, the correlation between HL and utility-based health-related quality of life (HRQOL) scores has been poorly documented. Therefore, we examined the correlation between HL and utility-based HRQOL scores in participants undergoing cardiac rehabilitation. The data of 448 participants undergoing cardiac rehabilitation from the Kobe-Cardiac Rehabilitation Project for People Around the World (K-CREW) clinical trial were analyzed. Participants were divided into low and high HL cohorts. We used the 14-item Health Literacy Scale (HLS-14) to assess HL and the EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire to assess HRQOL at discharge. The utility scores of the EQ-5D-5L questionnaire were calculated. The median age was 71.0 [61.0–78.0] years, 75.7% of participants were male, and 60% had a low HL. Median utility score was 0.88 [0.75–1.00]. Regarding the dimensions of the EQ-5D-5L questionnaire, more than 60% of participants responded positively to the severity level of “no problem.” In the comparative analysis, the low HL cohort had a statistically significantly lower utility score than that of the high HL cohort (p-value = 0.03). The multivariate analysis revealed that the HLS-14 scores were not statistically significantly correlated with the utility scores. Participants with low HL had lower HRQOL in the comparative analysis. However, multivariate analysis revealed that HL was not statistically significantly correlated with utility-based HRQOL scores. Future studies should explore the influence of confounding or intermediate variables on the correlation between HL and HRQOL.