Investigating a structured diagnostic pathway for chronic breathlessness in primary care: a feasibility cluster Randomised Controlled Trial

Introduction: A symptom-based pathway for chronic breathlessness with early investigations may reduce delays to diagnosis and improve patient outcomes. Aim: To conduct a feasibility trial of a multicentre cluster Randomised Controlled Trial (cRCT) investigating a structured diagnostic pathway versus usual care (UC) for adults presenting with chronic breathlessness in primary care. Methods: Patients over 40 years presenting with chronic breathlessness (>2 months), without an existing diagnosis, were recruited to a cRCT. Ten Family practices were cluster randomised to a structured diagnostic pathway (intervention) including early investigations, or UC. The primary feasibility outcomes were recruitment and retention rate at one year, to inform future trial design. Secondary outcomes included number of investigations and diagnoses at 3 and 12 months, and patient reported outcome measures (PROMs) assessing symptom burden (Chronic Heart Questionnaire, CHQ) and quality of life (EuroQoL 5 Dimension Utility Index, EQ5D-5L UI) at 6 months and one year. Results: Recruitment rate was 22% (48/220): 65% female, mean (SD) age 66 (11) years, BMI 31.2 (6.5), median (IQR) MRC dyspnoea 2 (2-3). Retention rate was 85% (41/48). The intervention group had a median (IQR) of 8 (7-9) tests compared with 5 (3-6) tests in UC within 3 months. 11/25 (44%) of the intervention group had a coded diagnosis at 12 months verses 6/23 (26%) in UC. The mean difference between the intervention and UC groups from baseline to twelve months was greater than the minimal clinical important difference for the Dyspnoea domain of the CHQ (1.0 ± 0.5) and the EQ5D-5L UI (0.12 ± 0.07). Discussion: A cRCT investigating a structured diagnostic pathway for adults with chronic breathlessness is feasible in primary care, with potential for more timely investigations and diagnoses. PROMs indicate potential patient level benefit and an adequately powered cRCT with health economic analysis is needed to investigate further.