COPD in an Academic Primary Care Practice: Defining the Population

Abstract

PURPOSE: To identify and define the population of patients diagnosed with COPD, Emphysema and Chronic Bronchitis in a primary care practice. METHODS: We performed a retrospective chart review of patients with a new diagnosis of COPD, Emphysema or Chronic Bronchitis (ICD-9 491.2, 491.9, 492.8) seen in the primary care practice of Tufts Medical Center from 2001 through 2016. Diagnostic accuracy was determined using clinic notes, pulmonary function testing and chest imaging. Patients were divided into two groups using Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria: COPD and Indeterminate. The COPD group included patients with one or more of the following: an obstructive ventilatory defect on spirometry, radiographic evidence of emphysema, a clinical history consistent with chronic bronchitis. Patients lacking these criteria were Indeterminate. Clinical and diagnostic covariates including age, gender, BMI, comorbidities, smoking history, frequency of pulmonary function testing (PFTs) and pulmonary consultation were compared between the two groups. Data were summarized using means (standard deviations) and n (%) where appropriate. Chi-square and T-test were used for between group comparisons. RESULTS: During the 15 year period, 290 patients seen in the Tufts primary care practice were given a new diagnosis of COPD, Emphysema or Chronic bronchitis. Eighty percent of these patients were correctly diagnosed with COPD (n¼53), Emphysema (n¼152) or Chronic Bronchitis (n¼27). Patients that were Indeterminate (n¼58) had a higher BMI (31.3 AE 7.6 vs. 27.4 AE 6.6, p < 0.0001) and a higher prevalence of a prior Asthma diagnosis (25.9% vs. 8.2%, p < 0.0001). There was no significant difference in age, sex, or primary language between the groups. Pulmonary function testing (45% vs. 74%, p < 0.0001) and pulmonary consultation (41% vs. 65%, p < 0.0009) were significantly less likely to have been performed in the Indeterminate group. CONCLUSIONS: In this academic primary care practice 20% of patients given a new diagnosis of COPD, Emphysema or Chronic Bronchitis were mis-or underdiagnosed as they had not undergone sufficient testing to support the diagnosis. These patients with an Indeterminate diagnosis were more overweight or to have a prior diagnosis of asthma than the COPD patients, implying that alternative diagnoses for their symptoms should be considered. Use of PFTs or pulmonary consultation was interestingly less frequent in this Indeterminate group. These data demonstrate that a significant proportion of patients given the diagnosis of COPD in primary care practices may be mis-identified. This has important implications for provider education, patient outcomes and health services utilization. CLINICAL IMPLICATIONS: Establishing a correct diagnosis of COPD has important implications for individual patients as appropriate clinical interventions can be associated with improved symptoms, functional capacity and quality and duration of life. Proper identification of COPD is also becoming more critical to ...