Over diagnosis of chronic obstructive pulmonary disease in the UK- cross sectional analysis of baseline data from Birmingham COPD cohort study
The problem
There is growing concerns that too many people are being over diagnosed and over-treated for a wide range of diseases, such as cancers, asthma, and chronic kidney disease. Consequently, people who do not have the disease will get permanent medical labels and lifelong treatments that will never benefit them, under-management of the true underlying disease and a waste of resources on unnecessary expenditures. From the clinical point of view, a correct diagnosis of COPD is essential because of its specific therapeutic and prognostic consequences on diagnosed patients. However, the focus in most of the literature is on COPD under-diagnosis and not much known about COPD over-diagnosis and over-treatment. We aimed to assess the magnitude of COPD over-diagnosis in the UK primary care settings and examine the characteristics of patients potentially over-diagnosed with COPD.
The approach
We analysed data on 1,473 GP diagnosed COPD patients aged 40 years and over who participated in the Birmingham COPD cohort study-UK. Patients were classified as non-COPD or confirmed-COPD based on post-bronchodilator spirometry results. Characteristics were compared using logistic regression adjusted for age, sex and smoking status.
Findings
Based on GOLD, LLN (GLI-2012 equations) and NICE 2004 definitions, 13.7%, 28.1% and 32.3% of participants were potentially over-diagnosed with COPD respectively. Restrictive pattern of lung disease was observed in 18.9% of non-COPD. Compared to confirmed-COPD, non-COPD were younger (mean age 67.2 versus 69.5 years, OR 0.98; 95% CI 0.96 - 0.99), more likely to be female (52.2% versus 35.4%, OR 0.5; CI 0.4 - 0.7), never smokers (22.9% versus 13.8%, OR 0.5; CI 0.4 - 0.7), obese (39.3% versus 31%, OR 1.7; CI 1.1 - 2.6), with multiple co-morbidities (23.9% versus 16.4%, OR 1.7; CI 1.1 - 2.6) and showed less FEV1 reversibility (10% versus 21.4%, OR 0.4; CI 0.2 - 0.7). Non-COPD participants were more likely to report previous asthma (47.3% versus 38.7%), coronary heart diseases (18.4% versus 14.2%), diabetes (18.9% versus 14.2%) and depression (21.4% versus 16.8%). But the difference between groups was insignificant.
Consequences
Over diagnosis was common. We identified female sex, obesity, restrictive lung pattern and multiple comorbidities as potential predictors for COPD over-diagnosis but recommend a follow-up assessment to examine for spirometry variability.
Credits
- Halima Buni
- Rachel Jordan
- Peymane Adab
- Alexandra Enocson
- Kar Keung Cheng