Effectiveness of case finding strategies for COPD in primary care: a systematic review and meta-analysis

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is widely underdiagnosed, but the most effective approach for identifying these patients is unknown.

Aims: The aim of this study was to summarise and compare the effectiveness of different case finding approaches for undiagnosed COPD in primary care.

Methods: A systematic review of primary studies of any design evaluating case finding strategies for COPD in primary care among individuals aged ⩾35 years with no prior diagnosis was conducted. Medline, Embase and other bibliographic databases were searched from 1997 to 2013, and methodological quality was assessed using standard tools. Results were described and meta-analysis of the uptake and yield from different approaches was performed where there was sufficient homogeneity.

Results: Three randomised controlled trials (RCTs), 1 controlled trial and 35 uncontrolled studies were identified that assessed the identification of new cases of COPD through systematic case finding. A range of approaches were used including pre-screening with questionnaires (n=13) or handheld flow meters (n=5) or direct invitation to diagnostic spirometry (n=30). Overall, any approach identified more undiagnosed COPD compared with usual care. Targeting those at higher risk (e.g., smokers) and pre-screening (e.g., using questionnaires) is likely to increase the yield. However, studies were heterogeneous and were limited by a lack of comparison groups, inadequate reporting and diversity in the definition of COPD, which limited our ability to draw firm conclusions.

Conclusions: There is extensive heterogeneity among studies evaluating case finding strategies for COPD, with few RCTs. Well-conducted RCTs comparing case finding approaches are needed to identify the most effective target population, recruitment strategy and screening tests, using a clinical definition of COPD, and addressing the limitations highlighted in this review. There is also a need to evaluate the impact of case finding on clinical care and patient outcomes.

Figure 1

Article selection.

Figure 2

Quality assessment. '*' indicates only studies evaluating screening questionnaires and/or handheld flow meters.

Figure 3

Random-effects meta-analysis of the proportion of eligible ever smokers diagnosed with COPD when opportunistically invited for spirometry (restricted to studies that defined airflow obstruction as FEV₁/FVC<0.7).