<p>Characteristics Associated with Accelerated Lung Function Decline in a Primary Care Population with Chronic Obstructive Pulmonary Disease</p>

Abstract

Background: Estimates for lung function decline in chronic obstructive pulmonary disease (COPD) have differed by study setting and have not been described in a UK primary care population. Purpose: To describe rates of FEV 1 and FVC decline in COPD and investigate characteristics associated with accelerated decline. Patients and Methods: Current/ex-smoking COPD patients (35 years+) who had at least 2 FEV 1 or FVC measurements ≥6 months apart were included using Clinical Practice Research Datalink. Patients were followed up for a maximum of 13 years. Accelerated rate of lung function decline was defined as the fastest quartile of decline using mixed linear regression, and association with baseline characteristics was investigated using logistic regression. Results: A total of 72,683 and 50,649 COPD patients had at least 2 FEV 1 or FVC measurements, respectively. Median rates of FEV 1 and FVC changes or decline were −18.1mL/year (IQR: −31.6 to −6.0) and −22.7mL/year (IQR: −39.9 to −6.7), respectively. Older age, high socioeconomic status, being underweight, high mMRC dyspnoea and frequent AECOPD or severe AECOPD were associated with an accelerated rate of FEV 1 and FVC decline. Current smoking, mild airflow obstruction and inhaled corticosteroid treatment were additionally associated with accelerated FEV 1 decline whilst women, sputum production and severe airflow obstruction were associated with accelerated FVC decline. Conclusion: Rate of FEV 1 and FVC decline was similar and showed similar heterogeneity. Whilst FEV 1 and FVC shared associations with baseline characteristics, a few differences highlighted the importance of both lung function measures in COPD progression. We identified important characteristics that should be monitored for disease progression.

Challenges and Pitfalls of Using Repeat Spirometry Recordings in Routine Primary Care Data to Measure FEV1 Decline in a COPD Population

“…Previous studies have investigated how patient characteristics are associated with FEV 1 decline; however, the purpose of this study was to primarily show how mean rates of FEV 1 decline differed depending on the definition used. [8][9][10]20,21 We found that in the cohorts that did not exclude measurements or individuals due to increases in FEV 1 , the mean rates of FEV 1 and within patient variation remained similar. For this reason, the definition used to create population one (i.e., using all available FEV 1 measurements over follow-up) could be used to describe the rate of FEV 1 decline in a COPD population using CPRD data.…”

“…The mean annual rates of FEV 1 decline described in this study for populations one and three to eight were similar to those reported in previous studies of COPD patients. 4,8,9 Interestingly, population two (those who were excluded due to potential measurement error) had faster rates of FEV 1 decline. More patients with low FEV 1 % predicted were excluded in this population, which meant that there were more patients with milder COPD (higher FEV 1 % predicted) than all other populations.…”

“…Whilst an FEV 1 measurement of 7 L would be considered high in COPD patients, a distribution of FEV 1 measurements was considered based off previous studies. [8][9][10] A previous validation study of spirometry in CPRD GOLD found that of 96.5% of spirometry traces recorded at the general practice in COPD patients were of adequate quality where a respiratory clinician was able to make an interpretation. 6 Of these, 27.9% were identified as post-bronchodilator FEV 1 , 7.2% were confirmed to be pre-bronchodilator FEV 1 , and for the remaining measurements it was unclear if the measurements were pre-or post-bronchodilator.…”

Predictors of Single Bronchodilation Treatment Response for COPD: An Observational Study with the Trace Database Cohort

“…In contrast, age does not seem to have a significant effect on response to treatment. This jeopardizes the traditional idea that COPD unquestionably progresses with age, in other words, that the older the lung function, the weaker the response to single bronchodilation [ 22 ]. In line with other previous authors, our data contradict this view of the disease [ 23 ].…”

Risk Factors of Rapid Lung Function Decline in COPD Patients of Real World

“…Besides demographic risk factors, including a higher age, a lower body mass index (BMI), being a current smoker, and more severe dyspnea (11,14), frequent or acute exacerbation events are important risk factors for the rapid decline in lung function (15)(16)(17). Recent studies indicate that acute exacerbation and a rapid decline in FEV 1 are related with high counts of blood eosinophils (18).…”