OBJECTIVES

: Medicine therapy-related quality of life (MTRQoL) is the difference between theoretically maximal obtainable and observed health-related quality of life (HRQoL) post-treatment. Health utility (HU) is a HRQoL measure that reflects both health status and preference for that health status. Little was known about the association between MTRQoL and HU. This study aimed to assess the relationship between MTRQoL and HU.

METHODS

: This study applied the database from our project “Psychometric properties of the Patient-Reported Outcomes Measure of Pharmaceutical Therapy for Quality of Life (PROMPT-QoL).” The sample of 1,156 patients was identified from three university hospitals in Bangkok, Thailand, between July 2014 and March 2015. Inclusion criterion were outpatients aged 18 or over who were continuously taking any medicines at least three months to treat their diseases. Exclusion criteria were the patients with cognitive impairment or with communicative or psychiatric problems. MTRQoL was measured by a novel instrument called the PROMPT-QoL which had 43 items with nine domains. Health utility measures included EQ-5D-5L and EQ-VAS. Multiple linear regression models using stepwise method were employed to evaluate the association between MTRQoL and HU.

RESULTS

: The regression model showed that EQ-5D-5L utility score had the highest significant correlation with Impact of Medicine and Side Effects follow by Satisfaction with Medicine Effectiveness, Psychological Impacts of Medication Use, and Availability and Accessibility domains of PROMPT-QoL, respectively (adjusted R = 13.7%). Another regression model demonstrated that EQ-VAS was highest associated with Satisfaction with Medicine Effectiveness, followed by Impact of Medicine and Side Effects and Overall QoL, respectively (adjusted R = 13.5%).

CONCLUSIONS

: This research found that the PROMPT-QoL explained about 14% of variance in EQ-5D-5L and EQ-VAS utility scores. This implies that these two concepts are different. Additionally, different HU methods are correlated with different domains of the PROMPT-QoL. More research can be done to explore these relationships.