BACKGROUND: Severity of chronic pulmonary obstructive disease (COPD) is an important predictor of COPD outcomes and mortality.
OBJECTIVE: To evaluate the availability of data on spirometry and symptoms using electronic medical records from the Clinical Practice Research Datalink (CPRD) in the United Kingdom (UK). To assess and compare the severity of COPD using the GOLD 2016 classification and an adapted algorithm.
METHODS: Cohort study of new users of aclidinium and other COPD medications between 2012 and 2015, aged ≥40 years with COPD. Severity was classified as GOLD A, B, C, or D according to a) % predicted FEV1 (recorded or estimated using expected FEV1 or FEV1); b) symptoms from the modified Medical Research Council (mMRC) dyspnoea grade, the COPD Assessment Test (CAT), or physician-recorded breathlessness; and c) exacerbation history. Severity was also classified using the adapted algorithm as mild, moderate, severe, and very severe based on intermittent/regular use of bronchodilators, exacerbations with/without hospitalisation, use of oxygen therapy, and lung transplantation, respectively.
RESULTS: The study included 67,195 new users of COPD medications aged ≥40 years with COPD. Spirometry results on recorded % predicted FEV1, expected FEV1, and FEV1 were available for 27.8%, 16.0%, and 78.5% of the patients, respectively. The % predicted FEV1 (recorded or estimated) was available for 81.3% of the patients. The mMRC, CAT, and breathlessness symptoms were available for 68.8%, 8%, and 23.8%, of patients, respectively. Symptoms could be assessed in 76.3% of the patients. Information to classify patients into GOLD 2016 categories was available for 76.3 % of patients. The GOLD 2016 definition classified more patients under the high-risk categories (59.5% GOLD C/D) than the adapted algorithm (43.8% severe/very severe).
CONCLUSIONS: In the CPRD, a high percentage of patients with COPD had recorded data on spirometry and symptoms that can be used to assess COPD severity using the GOLD 2016 definition. The adapted algorithm can be used in patients with missing information on spirometry or symptoms, although it may underestimate the prevalence of more severe COPD compared to the GOLD 2016 classification.
