Use of Opioids and Outcomes of Pneumonia: Results from the US Nationwide Inpatient Sample

BACKGROUND:Opioids have been shown to increase risk of pneumonia among susceptible population. However, the effect of opioid abuse on the outcome of pneumonia has not been evaluated at the population level. We aimed to compare the outcomes of pneumonia among patients with opioid use disorder and patients without substance use disorder using a large population database.METHODS:We assembled a pneumonia cohort composed of 11,186,564 adult patients from the National Inpatient Sample (NIS; 2005-2014). Patients with opioid disorder were identified using the International Classification of Diseases, 9th Revision, Clinical Modification codes. We compared health-related and economic outcomes between patients with and without opioid disorders using propensity score matching (PSM) analysis to balance baseline differences. The survival differences between two groups of patients were assessed using a Cox proportional hazard model. We further explored the possibility of effect modification by interaction analyses in different populations.RESULTS:After PSM, patients with opioid use disorder were at increased risk of ventilator use (odds ratio [OR]: 1.22, 95% confidence interval [CI]: 1.08 to 1.38, p = 0.0014) and associated with increased length of hospital stay by 0.59 days (95% CI: 0.35 to 0.83, p < 0.001), compared with those without substance use disorder. Patients with opioid use also had higher daily (228.00 USD, 95% CI: 180.51 to 275.49, p < 0.001) and total (1,875.72 USD, 95% CI: 1,259.63 to 2,491.80, p < 0.001) medical costs. Subgroup analyses showed similar results.CONCLUSIONS:Compared with patients without any drug dependence, patients with opioid use disorders had increased risk of complications and resource utilization. This study adds evidence for increased risk for pneumonia complications in the growing patients with opioid use disorders.