Effect of screening for undiagnosed COPD on respiratory hospitalisation and mortality; 4 year follow up of the TargetCOPD trial

Abstract

At least half of those with COPD are undiagnosed, but current guidelines do not recommend screening partly because evidence of clinical benefit is not available.

We previously conducted the TargetCOPD trial demonstrating that yield from active case-finding was significantly higher compared to routine practice (OR=7.45). We now report on clinical outcomes at 4yr follow up.

We obtained data through NHS Digital on mortality and hospitalisations (all-cause and respiratory) for 74,693 participants from all 54 practices in the TargetCOPD case-finding trial. Cox proportional hazard models, using random effects, adjusted for potential confounding factors were used to model time to event outcomes (first respiratory hospital admission, first all cause hospital admission and death) in the case-finding and routine arms. Time to event was censored at death or data extraction (Sept17) if no event occurred. Analyses were adjusted for a range of potential confounders, including age, sex, ethnicity and baseline values for lung function, comorbidities and smoking status.

Of the 32,743 participants in the case-finding arm, 1,557 had a respiratory hospitalisation compared to 1,899/ 41,950 in the routine arm over a mean follow up of 4.3 years (adjusted hazard ratio (HR) 1.04; 95% CI: 0.73, 1.47). The corresponding HR for all cause hospitalisation and mortality were 1.06 (0.66, 1.71) and 1.15 (0.82, 1.61) respectively.

Thus despite screening resulting in higher yield, there were no differences in clinical outcomes at 4 years. Further research is needed to understand the process of management following screening and the effectiveness of existing treatments in case-found patients.