Diagnosis of the cause of chronic dyspnoea in primary and tertiary care: characterizing diagnostic confidence

Yao C Huang, Olivia R Ferry, Scott C McKenzie, Rayleen V Bowman, Michael Hamilton, Philip J Masel, Kwun M Fong, Ian A Yang

Chronic dyspnoea (breathlessness) in adults is a common symptom, the exact cause of which may be difficult to diagnose on initial presentation. We characterised the diagnostic complexity of chronic dyspnoea in primary care and tertiary care. This retrospective observational study screened consecutive referral letters of all adult patients referred to cardiology or respiratory clinics at a tertiary referral hospital, during May to June 2015. For patients referred due to chronic dyspnoea, data were analysed from the initial referral letter and subsequent specialist clinic letters for the 6-month time period after referral. Of 1,370 patient referrals, 122 patients (mean age 63 y, 55% female) were referred due to chronic dyspnoea. One hundred and five patients (86%) were referred from primary care and 17 (14%) from other hospital clinics. Sixty-one percent were referred with an evident diagnosis (referrer was confident of the initial diagnosis), whereas 39% had non-evident or unclear diagnoses. By 6 months after referral, a definitive final diagnosis had been determined by the specialist clinics in 62% of patients. The majority of patients had been referred appropriately to a cardiology or respiratory clinic, based on the final diagnosis. However, only 26% of diagnoses were fully concordant between the initial referrer diagnosis and the final specialist clinic diagnosis, with 26% being partially concordant and 48% non-concordant. Diagnostic certainty of the referrer was associated with concordance of diagnosis between the referrer and specialist clinic (P<0.001). In adult patients referred due to chronic dyspnoea to hospital specialist clinics, there is considerable diagnostic uncertainty about its aetiology, for both referring doctors and specialist clinics. These results demonstrate the current difficulty in diagnosing the cause of chronic dyspnoea in adults, and highlight the need for evidence-based diagnostic pathways.