Mapping the clinical chronic obstructive pulmonary disease questionnaire onto generic preference-based EQ-5D values

Area of Science:

• Health Outcomes Research
• Patient-Reported Outcomes

Background:

• Chronic Obstructive Pulmonary Disease (COPD) management relies on accurate health status assessment.
• EuroQol five-dimensional questionnaire (EQ-5D) and clinical chronic obstructive pulmonary disease (COPD) questionnaire (CCQ) are commonly used patient-reported outcome measures.

Purpose of the Study:

• To develop and validate predictive models for EQ-5D values using CCQ scores.
• To assess the performance of these models across different populations and EQ-5D value sets.

Main Methods:

• Utilized data from three clinical trials (RECODE, GO-AHEAD, MARCH).
• Employed correlation and principal-component analysis to explore CCQ-EQ-5D relationships.
• Developed and validated various regression models using estimation and validation samples, assessing internal and external validity.

Main Results:

• CCQ domains 'functional state' and 'mental state' correlated with four EQ-5D dimensions; 'pain/discomfort' was independent.
• Models showed good agreement for mean EQ-5D values in internal validation but significant differences in external validation.
• Systematic underestimation in mild health states and overestimation in severe health states were observed.

Conclusions:

• Predictive models can approximate mean EQ-5D values in similar populations.
• The observed biases in predicting EQ-5D values for mild and severe health states restrict their utility in Markov models.
• Cautious application of mapping techniques is recommended for COPD health status assessment.