Introduction

Obstructive Lung Disease-Questionnaire (OLD-Q) is a potential new tool for monitoring disease burden in both asthma and COPD. OLD-Q was developed in patients with asthma or COPD in a specialized referal center by merging/reducing questions of asthma control questionnaire (ACQ) and clinical COPD questionnaire (CCQ). It contains 9 items on a 6-point scale. Validation in primary care and in asthma-COPD overlap (ACO) specifically are next steps.

Aim

Validate OLD-Q in patients with ACO in tertiary care and patients with obstructive lung disease in primary care

Methods

Data of ACO patients in tertiary care were obtained from the same hospital as the development cohort. Data of patients with asthma, COPD or ACO were derived from a primary care center in Rotterdam. ACQ-5 and CCQ were completed on the same day. Linear regression and Principal Component Analysis(PCA) were used and compared to PCA of the development cohort.

Results

53 patients with ACO in tertiary care and 2.506 in primary care (asthma: n=1110, COPD: n=1041, ACO: n=355) were included. Correlation between ACQ and CCQ was 0.83 in ACO patients in tertiary cohort. In the primary cohort, correlation was 0.81 in asthma, 0.80 in COPD, and 0.81 in ACO. PCA of both validation cohorts resulted in similar selection of questions as the original OLD-Q and therefore needed no change in item selection. Alpha Cronbach?s showed high reliability.

Conclusion

Validation of the OLD-Q in ACO and in primary care resulted in similar results as in the development cohort. This implies that this new, practical tool for measuring disease burden might be applicable in all patients with obstructive lung disease.