Future diagnosis following recorded presentation of symptoms of breathlessness and wheeze in primary care

Problem

The potential to improve patient outcomes through earlier intervention makes research into prodromal symptoms of chronic disease an important priority. Presenting symptoms may be due to a self-limiting condition, or could be an early sign of a number of morbidities. For example, common respiratory symptoms such as breathlessness or wheeze may be a marker for pulmonary or cardiovascular disease. The aim was to assess the risk of future diagnosis of chronic obstructive pulmonary disease (COPD), asthma, and ischaemic heart disease (IHD) following a recorded primary care consultation for breathlessness or wheeze symptoms.

Approach

This was a retrospective cohort study of adults aged ≥18 years, performed within the Clinical Practice Research Datalink (CPRD). Patients with a first coded record of breathlessness or wheeze symptom in primary care at any point between 1997-2010 and with no prior diagnostic record of COPD, asthma, IHD or other respiratory disease were identified as the ‘exposed’ cohort. They were then matched by age, gender and practice to an ‘unexposed’ cohort who also had no prior diagnosis of COPD, asthma, IHD or other respiratory disease, nor had a recorded breathless or wheeze symptom. The risks of future diagnosis of COPD, asthma and IHD were then compared using Cox proportional hazards models with adjustment for socio-demographic characteristics and comorbidity, and stratifying the follow-up period into 0-6 months after initial recorded symptom, 6-12 months, 12-36 months and >36 months.

Findings

There were 265,940 patients identified for both cohorts (42% male; median age 60 (IQR 44, 73)), with a median follow-up of 6.1 years. In the exposed cohort, incidence of COPD was 209 per 10,000 person years (asthma 294/10,000; IHD 287/10,000). In the unexposed cohort, incidence of COPD was 38/10,000; asthma 31/10,000; IHD 108/10,000. Patients recorded with breathlessness/wheeze had a significantly higher risk of future diagnosis of COPD, asthma and IHD. The relationships were strongest during the first 6 months of follow-up but a significant relationship persisted even after 36 months. Median time from first recorded breathlessness/wheeze to diagnosis was 665 days for COPD, 391 days for asthma, and 616 days for IHD.

Consequences

Presentation to primary care of breathlessness and wheeze can be an early indicator of later diagnoses of asthma, COPD and IHD. Delay in diagnosis suggests that GPs should consider the need for further assessment, targeted investigations, referrals, risk management, and health and lifestyle advice when presented with a symptom for which a diagnosis is not initially clear.