Case-Finding and Treatment Effects in COPD: Secondary Analysis of an Interdisciplinary Intervention Trial

Kate Petrie,1 Michael J Abramson,2 Johnson George1,2 1Centre for Medicine Use and Safety, Monash University, Melbourne, Victoria, Australia; 2School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, AustraliaCorrespondence: Johnson George, Centre for Medicine Use and Safety, Monash University, Melbourne, Victoria, Australia, Email johnson.george@monash.eduBackground: US Preventive Services Taskforce recommends against screening for COPD in asymptomatic adults due to limited evidence on the efficacy of treatments for this population. However, global and Australian guidelines recommend a case-finding approach where those with symptoms and/or risk factors, including smoking, are screened. This study aims to explore patient characteristics by time of COPD diagnosis and the effectiveness of early treatment in those with or without symptoms.Methods: Secondary analysis of a randomised controlled trial that included those with a pre-existing (n=130) or new diagnosis (n=142) of COPD. Those randomised to the intervention arm received an interdisciplinary intervention of smoking cessation support, home medicines review and home-based pulmonary rehabilitation, while controls received usual care. The primary outcome was health-related quality of life (HR-QoL) measured using St George’s Respiratory Questionnaire. To estimate the impact of early treatment, we compared the effectiveness of treatment versus control at 6- and 12-months for the new versus pre-existing diagnosis groups, and those symptomatic versus asymptomatic or minimally symptomatic based on COPD Assessment Test score.Results: Approximately half of those newly diagnosed with COPD were already symptomatic. Early treatment in those diagnosed via case-finding had a positive non-significant impact on HR-QoL. The size of the treatment effects generally favoured the pre-existing diagnosis group when compared to case-finding and favoured those symptomatic when compared to those asymptomatic.Conclusion: Despite useful insights into the impacts of case-finding and early treatments, this study, like most others, was not sufficiently powered. Further larger studies or combining sub-groups across studies are required.Keywords: RCT, screening, interdisciplinary, COPD