Asthma and COPD – how often do patients have both conditions?

04 Jun 2018

Asthma and COPD share many characteristics and symptoms, and the differential diagnosis between the two diseases can be difficult in primary care. Francis Nissen and colleagues have recently done a study to quantify how commonly patients with chronic obstructive pulmonary disease (COPD) have a concomitant diagnosis of asthma, and how commonly patients with asthma have a concomitant diagnosis of COPD in UK primary care. They found that a concurrent asthma and COPD diagnosis only affects a relative minority of patients with COPD (14.5%) or asthma (14.8%), and that asthma diagnoses may be over-recorded in people with COPD.

The study was based upon data from previous validation studies, including 400 COPD patients and 352 asthma patients from the Clinical Practice Research Datalink (CPRD), with disease status confirmed by review of questionnaires sent to general practitioners (GPs). The prevalence of concurrent asthma and of COPD in validated cases of either disease was examined based on CPRD coding, GP questionnaires and requested additional information. More than half (52.5%) of validated COPD patients had ever received a diagnostic asthma Read code. However, when considering additional evidence to support a diagnosis of asthma, concurrent asthma was only likely in 14.5% of validated COPD patients. Of the validated asthma patients, 15.1% had a diagnostic COPD Read code, although COPD was only likely in 14.8% of validated asthma patients. The full paper has just been accepted for publication in the British Journal of General Practice.