Estimating utility data from clinical indicators for patients with stable angina

Area of Science:

• Cardiovascular Medicine
• Health Economics
• Outcomes Research

Background:

• Estimating quality-adjusted life years (QALYs) is crucial for health economic evaluations.
• Clinical trials often collect patient-reported outcomes but not direct utility measures.
• Angina patients' health-related quality of life (HRQL) data needs a reliable method for utility mapping.

Purpose of the Study:

• To develop and validate a model for mapping routinely collected clinical data to a health utility scale.
• To enable the estimation of QALYs in angina clinical trials using existing data.
• To provide a tool for economic evaluations in the absence of direct utility measurements.

Main Methods:

• Regression analysis was employed to predict EQ-5D index values.
• Data from 510 stable angina patients from UK cardiac out-patient clinics were utilized.
• The model incorporated Canadian Cardiovascular Society (CCS) angina classification, breathlessness grades, and medication data.

Main Results:

• The final model predicted EQ-5D scores using CCS grades, breathlessness, and medications, achieving an R2 of 0.37.
• Mean EQ-5D scores varied significantly across CCS and breathlessness grades, indicating distinct utility levels.
• Model predictions were more reliable for less severe angina cases compared to severe cases.

Conclusions:

• A feasible model exists to map routine clinical data to health utility values for angina patients.
• This approach facilitates QALY estimation and economic evaluations in clinical trials lacking direct utility data.
• Users should consider the inherent uncertainty in the model's estimates, particularly for severe angina.