Treatment burden mediates the association between the number of comorbidities and health-related quality of life in young and middle-aged patients with hypertension and comorbidities
Authors: Lee J , Lee K S 
Published: July 2023

Abstract

Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Research Foundation of Korea grants funded by the Korea government (2021R1C1C100849812).

Background
The patient-reported outcome such as health-related quality of life (HRQoL) is important in providing patient-centered care to patients with hypertension. Previous studies have shown that comorbidities are negatively associated with HRQoL in patients with hypertension. To effectively improve their HRQoL, it is crucial to comprehend the mechanism of how comorbid diseases affect the HRQoL. Patients with multimorbidity experience an increased burden of treatment associated with simultaneously managing multiple chronic conditions. The treatment burden can contribute to poor HRQoL. Therefore, we hypothesize that treatment burden mediates the association between the number of comorbidities and HRQoL among patients with hypertension. Because most studies on the HRQoL of patients with hypertension have been conducted in older people, levels of treatment burden are different between older and younger patients, this study was conducted in young and middle-aged hypertensive patients with comorbidities.

Purpose
To examine the mediating effect of treatment burden on the association between the number of comorbidities and HRQoL in young and middle-aged hypertensive patients with comorbidities.

Methods
Hypertensive patients (age 19-54 years) with additional diseases completed the cross-sectional questionnaire survey. The number of comorbidities was measured based on self-report using the list of 20 or more chronic conditions. The treatment burden was measured with the 13-item Multimorbidity Treatment Burden Questionnaire, and high scores indicate a higher level of treatment burden. HRQoL was measured with the Patient-Reported Outcomes Measurement Information System-29 profile v2.1 (PROMIS-29 v2.1). The scores from the PROMIS-29 v2.1 were used to compute the PROMIS-Preference scores, which is a summary score of the HRQoL. The PROMIS-Preference scores ranged from 0 (bad health) to 1 (ideal health). To examine the mediating role of treatment burden on the relationship between the number of comorbidities and HRQoL, the mediation analysis was performed after adjusting for sex. This analysis was conducted using Mplus 8.8 with 5000 bootstrap samples.

Results
A total of 186 hypertensive patients with comorbidities (mean age 44.9 years; 72% male) were included in this study. Patients had an average of 2.6 additional chronic conditions along with hypertension. (SD: 1.7). The mean HRQoL score was 0.35 (SD: 0.21). The direct effect of the number of comorbidities on HRQoL was significant, and the indirect effect mediated by treatment burden was also significant (Figure).

Conclusion
We found that the treatment burden mediated the association between the number of comorbidities and HRQoL in young and middle-aged patients with hypertension and comorbidities. These findings suggest that strategies to lower the treatment burden are important to improve the HRQoL in this population.