Multimorbidity and COPD medication receipt among medicaid beneficiaries with newly diagnosed COPD

BACKGROUND: Multimorbidity is highly prevalent among patients with COPD. The association between multimorbidity and COPD medication management is not well researched. The aim of this study was to examine the association between multimorbidity and COPD medication receipt among Medicaid beneficiaries with newly diagnosed COPD. METHODS: A retrospective longitudinal dynamic cohort design was used, and data were extracted from Medicaid Analytic eXtract files from 2005 to 2008. Medicaid beneficiaries with newly diagnosed COPD (N 19,060) were identified using the International Classification of Diseases, 9th Revision, Clinical Modification, for COPD. This code (for commonly co-occurring conditions with COPD) was used to create a multimorbidity variable. These conditions included anxiety, arthritis, bipolar disorder, cardiovascular diseases, depression, diabetes, hypertension, hyperlipidemia osteoporosis, and schizophrenia. Medicaid beneficiaries with newly diagnosed COPD were categorized as: (1) physical multimorbidity only, (2) psychiatric multimorbidity only, (3) both physical and psychiatric multimorbidity, and (4) no multimorbidity. Receipt of COPD medications (short-or long-acting bronchodilators, inhaled corticosteroids) was identified using National Drug Codes. Bivariate relationships between multimorbidity and COPD medication receipt were tested using the chi-square test of independence. The associations between multimorbidity and COPD medication receipt were analyzed with logistic and multinomial logistic regression analyses. RESULTS: Among Medicaid beneficiaries with newly diagnosed COPD, 81.9% had at least one co-occurring chronic condition. After controlling for subject characteristics, adults with multimorbidity were less likely to receive COPD medications compared with those without any inflammation-related multimorbidity. For example, those with physical multimorbidity were less likely to receive short-acting bronchodilators (adjusted odds ratio [OR] 0.76, 95% CI 0.69 - 0.83), long-acting bronchodilators (adjusted OR 0.84, 95% CI 0.76 - 0.92), and inhaled corticosteroids (adjusted OR 0.75, 95% CI 0.68 - 0.82) compared with those with no inflammation-related multimorbidity.CONCLUSIONS: The prevalence of multimorbidity is very high among Medicaid beneficiaries with newly diagnosed COPD. Our findings indicate poor COPD medication management among those with multimorbidity.