C2.5 COPD case finding
The US Preventive Services Task Force reviewed the evidence on screening asymptomatic adults for COPD using questionnaires or office-based screening pulmonary function testing from January 2000 to January 2015. The review found no direct evidence to determine the benefits and harms of screening or to determine the benefits of treatment in screen-detected populations. On this basis, screening of asymptomatic adults was not recommended (Guirguis-Blake 2016, U. S. Preventive Services Task Force 2016). A targeted systematic review commissioned by the USPSTF to update the evidence on the effectiveness of screening asymptomatic adults found no new studies over the subsequent period January 1, 2015, to March 25, 2022 (Webber 2022) [evidence level I].
Simple lung function tools can assist practitioners in the case finding of individuals who have undiagnosed COPD. The devices measure the amount of exhaled air in the first 1 and 6 seconds of expiration (FEV1, FEV6) and calculate FEV1/FEV6, which is the ratio of the amount of air forcibly exhaled in the first second relative to the first 6 seconds. Schnieders et al (2021) published a systematic review and meta-analysis of the performance of micro-spirometers or two questionnaires compared to post-bronchodilator spirometry for detection of COPD. The meta-analysis included 17 studies. The overall area under the curve (AUC) of micro-spirometers was 0.84 (95% CI 0.80–0.89). For questionnaires the AUC for the COPD population screener (COPD-PS) questionnaire was 0.77 (95% CI 0.63–0.85) and the COPD diagnostic questionnaire (CDQ) was 0.72 (95% CI 0.64–0.78) (Schnieders 2021). If spirometry is unavailable either a micro spirometer or questionnaire are useful tests for early detection.
Lung Foundation Australia’s Position Paper: COPD case finding in community settings, recommends that previously undiagnosed individuals aged 35 years or older should be assessed with the symptom checklist, followed by a COPD screening device with an FEV1/FEV6 cut-off < 0.75. Individuals with an FEV1/FEV6 ratio < 0.75 should undergo formal diagnostic spirometry. Symptomatic individuals with an FEV1/FEV6 ratio ≥ 0.75 should be encouraged to visit their general practitioner as they may be at risk of other diseases or lung conditions and may require more formalised testing.
In a retrospective analysis of health data in Canada (Johnson 2020), over 99% of people with COPD had incurred at least one visit in any of the previous 5 years prior to recording of the diagnosis. This study highlights the potential for earlier diagnosis, and intervention.
COPD is commonly undiagnosed, until presentation requiring a hospital admission. A review of 39 studies with a variety of case finding strategies, including five studies comparing earlier diagnostic strategies with usual care, has found that postal questionnaire approaches had poor results, while active opportunistic case finding through primary care had greater chance of detection (Haroon 2015). Practice led symptom questionnaires of patients clinically suspected to have COPD, followed by diagnostic assessment, had the best diagnostic yields. Widespread population screening for COPD is not recommended (Guirguis-Blake 2016, U. S. Preventive Services Task Force 2016).
Based upon an analysis of 4,484 COPD subjects in the ‘Genetic Epidemiology of COPD cohort’, DeMeo et al demonstrated that females are more susceptible to the effects of COPD than males with respect to symptom burden, including severity of dyspnoea, and exacerbation risk, especially in younger females. Given this greater COPD burden, the study highlighted the potential of under diagnosis as well as under treatment of COPD in females (DeMeo 2018). Retrospective data suggests that females are at higher risk of presenting with a moderate or severe exacerbation than men (Stolz 2019). A large study (29,678) of randomly selected residents of Copenhagen aged between 40 and 80 found 11% had FEV1/FVC <0.70 and FEV1 <80% of predicted on pre-bronchodilator spirometry. Treatable problems were identified in many of these participants, including smoking (45%), insufficient physical activity (12%), obesity (28%), undiagnosed hypertension (28%) and undiagnosed hypercholesterolaemia (48%) (Çolak 2022).
Patients that are added to a COPD register as a result of a systematic screening programme (Haroon 2020) received significantly higher levels of appropriate clinical care. However only one in five case-found patients were actually registered in the database to potentially go on to receive such care. Case finding is only likely to improve clinical care if patients with newly identified disease are promptly added to an active primary care COPD register.
 Level of evidence could not be assigned due to heterogeneity