# Measuring burden of disease in both asthma and COPD by merging the ACQ and CCQ: less is more?

## TL;DR

Researchers combined two questionnaires to create a shorter one for assessing disease burden in asthma, COPD, and overlapping conditions.

## Contribution

A new nine-question tool for obstructive lung diseases was developed by merging and reducing items from ACQ and CCQ.

## Key findings

- ACQ and CCQ showed strong correlation in asthma (R = 0.82) and COPD (R = 0.83).
- PCA identified nine questions that effectively assess disease burden across asthma, COPD, and ACO.
- The new questionnaire performed consistently in both primary and secondary care settings.

## Abstract

Symptoms of asthma and COPD often overlap, and both diseases can co-exist in one patient. The asthma control questionnaire (ACQ) and clinical COPD questionnaire (CCQ) were developed to assess disease burden in respectively asthma or COPD. This study explores the possibility of creating a new questionnaire to assess disease burden in all obstructive lung diseases by integrating and reducing questions of the ACQ and CCQ. Data of patients with asthma, COPD and asthma-COPD overlap (ACO) were collected from a primary and secondary care center. Patients completed ACQ and CCQ on the same day. Linear regression tested correlations. Principal Component Analysis (PCA) was used for item reduction. The secondary cohort with asthma and COPD patients was used for initial question selection (development cohort). These results were reproduced in the primary care cohort and secondary cohort of patients with ACO. The development cohort comprised 252 patients with asthma and 96 with COPD. Correlation between ACQ and CCQ in asthma was R = 0.82, and in COPD R = 0.83. PCA determined a selection of 9 questions. Reproduction in primary care data (asthma n = 1110, COPD n = 1041, ACO = 355) and secondary care data of ACO patients (n = 53) resulted in similar correlations and PCA-derived selection of questions. In conclusion, PCA determined a selection of nine questions of the ACQ and CCQ: working title ‘the Obstructive Lung Disease Questionnaire’. These results suggest that this pragmatic set of questions might be sufficient to assess disease burden in obstructive lung disease in both primary as secondary care.