OBJECTIVES: Chronic lung disease, specifically COPD and asthma, impacts more than 500 million adults worldwide, and is associated with high healthcare spending and significant disease related morbidity. While the direct impact of substance use disorder is well documented, little is known about the indirect impact of substance misuse within this patient population. Utilizing administrative data, we quantified the secondary morbidity, mortality and healthcare utilization attributable to substance misuse in patients with chronic lung disease on a national scale

METHODS: Utilizing the National Readmissions Database we identified patients with a diagnosis of COPD or asthma admitted to a hospital within the United States between 2012-2015. Within this patient subgroup, ICD-9/10-CM codes were utilized to determine the prevalence of substance misuse by drug class. Utilizing weighted regression analysis, morbidity, mortality and healthcare utilization differences between the two groups were identified. The impact of tobacco use, with or without associated substance misuse, was determined, and adjusted for in final analysis.

RESULTS: 1,087,226 patients with an index admission for COPD or asthma were identified. Of these patients 4.01% had a documented diagnosis of substance misuse. Patients with documented substance misuse of any kind had an increased cost per index admission, with an increased risk of respiratory failure (OR: 1.44 (95%CI: 1.37, 1.52, p<0.001) and need for mechanical ventilation (OR 1.44 (95%CI: 1.37, 1.52 p <0.05). The additional index admission costs totaled $24 million for our cohort. Additionally substance misuse was associated with an increased risk of readmission. (OR 1.29 95%CI: 1.25, 1.33 p<0.001).

CONCLUSIONS: Substance misuse is associated with an increase in healthcare utilization and healthcare cost in patients with chronic lung disease. Targeted substance misuse treatment in this patient population has the potential for significant cost savings to the healthcare system.