Inaccurate diagnosis of COPD: the Welsh National COPD Audit

Background The diagnosis of chronic obstructive pulmonary disease (COPD) is confirmed with spirometry demonstrating persistent airflow obstruction.

Aim To evaluate the clinical characteristics and management of patients in primary care on COPD registers with spirometry incompatible with COPD.

Design and setting A primary care audit of Welsh COPD Read-Coded patient data from the Quality and Outcomes Framework (QOF) COPD register in Wales.

Method Patients on the QOF COPD register with incompatible spirometry (post-bronchodilator forced expiratory lung volume in 1 second/forced vital capacity [FEV1/FVC] ratio ≥0.70) were compared with those with compatible spirometry (FEV1/FVC <0.70).

Results This audit included 63% of Welsh practices contributing 48 105 patients. Only 19% (n = 8957) of patients were post-bronchodilator FEV1/FVC Read-Coded and were included in this study. Of these, 75% (n = 6702) had compatible spirometry and 25% (n = 2255) did not. Patients with incompatible spirometry were more likely female (P = 0.009), never-smokers (P<0.001), had higher body mass index (P<0.001), and better mean FEV1 (P<0.001). Medical Research Council (MRC) breathlessness scores, exacerbation frequency, and asthma co-diagnosis were similar between groups. Patients in both groups were just as likely to receive inhaled corticosteroid (ICS) and long-acting beta-agonists (LABAs), but patients with incompatible spirometry were less likely to receive long-acting muscarinic antagonists (LAMAs) (P<0.001) or LABA/ICS (P = 0.002) combinations.

Conclusion Patients on the COPD QOF register with spirometry incompatible with COPD are symptomatic and managed using significant resources. If quality of care and effective resource use are to be improved, focus must be given to correct diagnosis in this group.