Comorbidity Associations with AATD Among Commercially Insured and Medicare Beneficiaries with COPD in the US

Introduction: Alpha-1 antitrypsin deficiency (AATD) is often not identified in patients with chronic obstructive pulmonary disease (COPD) until advanced stages of disease, despite the availability of genetic testing. While clinical practice guidelines provide recommendations on patients who should be tested, more refined algorithms are needed to identify COPD patients who are likely candidates for AATD testing and to prevent delays in diagnosis and treatment. The objective of this study was to identify comorbid associations with AATD among patients diagnosed with COPD in the United States. Methods: Using data from the 2012-2017 PharMetrics Plus Administrative Claims Database and 2011-2014 Medicare Fee for Service 5% Sample, patients with COPD (ICD-9-CM: 491.xx, 492.xx, or 496, ICD-10-CM J41, J42, J43, J44) and AATD (ICD-9-CM: 273.4, ICD-10-CM: E88.01) were identified. Patient demographic and diagnostic characteristics were assessed. Logistic regression models were developed to identify significant predictors of AATD. Results: A cohort of 344,528 Medicare beneficiaries with COPD (of which 302 (0.09%) also had two diagnoses of AATD) and a cohort of 340,259 commercially insured patients with COPD (of which 1076 (0.3%) also had a diagnosis of AATD) were constructed. Associations with AATD identified in both models included ICD-9-CM and ICD-10-CM codes for chronic pulmonary heart disease, chronic liver disease and cirrhosis, and liver transplant. Discussion: Significant associations with a diagnosis of AATD among patients with COPD were consistently represented in each of the datasets evaluated, which suggests meaningful comorbidity implications in AATD patients. These findings reinforce the need to test individuals with COPD for AATD as early as possible to help reduce the development of associated comorbid conditions.