Investigating a structured diagnostic approach for chronic breathlessness in primary care: a mixed-methods feasibility cluster randomised controlled trial

Background There is a need to reduce delays to diagnosis for chronic breathlessness to improve patient outcomes.Objective To conduct a mixed-methods feasibility study of a larger cluster randomised controlled trial (cRCT) investigating a structured symptom-based diagnostic approach versus usual care for chronic breathlessness in primary care.Methods 10 general practitioner practices were cluster randomised to a structured diagnostic approach for chronic breathlessness including early parallel investigations (intervention) or usual care. Adults over 40 years old at participating practices were eligible if presenting with chronic breathlessness without an existing explanatory diagnosis. The primary feasibility outcomes were participant recruitment and retention rate at 1 year. Secondary outcomes included number of investigations at 3 months, and investigations, diagnoses and patient-reported outcome measures (PROMs) at 1 year. Semistructured interviews were completed with patients and clinicians, and analysed using thematic analysis.Results Recruitment rate was 32% (48/150): 65% female, mean (SD) age 66 (11) years, body mass index 31.2 kg/m2 (6.5), median (IQR) Medical Research Council dyspnoea 2 (2-3). Retention rate was 85% (41/48). At 3 months, the intervention group had a median (IQR) of 8 (7-9) investigations compared with 5 (3-6) investigations with usual care. 11/25 (44%) patients in the intervention group had coded diagnosis for breathlessness at 12 months compared with 6/23 (26%) with usual care. Potential improvements in symptom burden and quality of life were observed in the intervention group above usual care.Conclusions A cRCT investigating a symptom-based diagnostic approach for chronic breathlessness is feasible in primary care showing potential for timely investigations and diagnoses, with PROMs potentially indicating patient-level benefit. A further refined fully powered cRCT with health economic analysis is needed.