New publication from our Health Economics theme – Mapping functions for the PHQ-9 and GAD-7 to generate EQ-5D-3L for economic evaluation
Clara Mukuria, Matthew Franklin, Sebastian Hinde
Researchers from ARC Y&H have developed an alternative approach for estimating overall quality of life in mental health studies, even when standard measures aren’t available. Overall quality of life is important as it can be combined with length of life to generate “quality adjusted life years’ (QALYs) which are used when assessing if a treatment is worth its costs. However, in many clinical trials for depression and anxiety treatments, researchers use questionnaires such as the Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) to measure symptoms.
The team, led by Clara Mukuria, Matthew Franklin, and Sebastian Hinde, wanted to find a way to convert PHQ-9 and GAD-7 scores into a measure called the EQ-5D-3L. This measure is commonly used to calculate QALYs. Using data from four clinical trials involving patients with depression symptoms, the researchers created mathematical models to predict EQ-5D-3L scores based on PHQ-9 and GAD-7. They tested different types of models and found that one called the “adjusted limited dependent variable mixture model” worked best.
The results will allow researchers to estimate quality of life improvements in studies that only used PHQ-9 and GAD-7 questionnaires. This information can help decision-makers better understand the value of different mental health treatments. The researchers hope their work will make it easier to conduct economic evaluations of mental health treatments, potentially leading to better healthcare decisions and improved patient care.
