Derivation of normative data for the COPD assessment test (CAT)

Area of Science:

• Pulmonary Medicine
• Clinical Epidemiology

Background:

• Traditional COPD classification using spirometry overlooks disease heterogeneity.
• The COPD Assessment Test (CAT) is recommended for assessing COPD patient health status.
• Limited normative data exists for CAT in non-COPD populations, hindering optimal cut-off determination.

Purpose of the Study:

• To characterize COPD Assessment Test (CAT) normative values in a non-COPD population.
• To evaluate the psychometric properties of the CAT questionnaire.
• To identify predictors of high CAT scores in individuals without COPD.

Main Methods:

• The CanCOLD study, a population-based cohort, administered CAT questionnaires to subjects with COPD, at-risk smokers, and healthy controls.
• Normative values and psychometric properties of the CAT were analyzed in 500 non-COPD subjects.
• Multivariable logistic regression identified predictors of high CAT scores (≥16).

Main Results:

• The mean CAT score in non-COPD subjects was 6 (SD 5.09), with higher scores in females and those over 80.
• Internal consistency for the CAT was high (Cronbach alpha = 0.79).
• Current smoking, asthma, and musculoskeletal disease were significantly associated with CAT scores ≥16.

Conclusions:

• Characterizing CAT scores in the general population provides a basis for norm-based comparisons.
• Longitudinal follow-up is needed to optimize CAT score cut-offs for clinical use.