Rising rates of injection drug use associated infective endocarditis in Virginia with missed opportunities for addiction treatment referral: a retrospective cohort study

Background: Injection drug use (IDU) is a growing public health threat in Virginia, though there is limited knowledge of related morbidity. The purpose of this study was to describe the temporal, geographic and clinical trends and characteristics of infective endocarditis associated with IDU (IDU-IE) and to identify opportunities for better-quality care of people who inject drugs (PWID). Methods: We reviewed charts for all admissions coded for both IE and drug use disorders at the University of Virginia Medical Center (UVA) from January 2000 to July 2016. A random sample of 30 admissions coded for IE per year were reviewed to evaluate temporal trends in the proportion of IDU associated IE cases. Results: There were a total of 76 patients with IDU-IE during the study period, 7.54-fold increase (prevalence ratio: 8.54, 95% CI 3.70-19.72) from 2000 to 2016. The proportion of IE that was IDU-associated increased by nearly 10% each year (prevalence ratio of IDU per year: 1.09, 95% CI: 1.05-1.14). Patients with IDU-IE had longer hospital stays [median days (interquartile range); IDU-IE, 17 (10-29); non-IDU-IE, 10 (6-18); p-value = 0.001] with almost twice the cost of admission as those without IDU [median (interquartile range); IDU-IE, $47,899 ($24,578-78,144); non-IDU-IE, $26,460 ($10,220-60,059); p-value = 0.001]. In 52% of cases there was no documentation of any discussion regarding addiction treatment. Conclusion: IDU-IE is a severe infection that leads to significant morbidity and healthcare related costs. IDU-IE rates are increasing and will likely continue to do so without targeted interventions to help PWID. The diagnosis and treatment of IDU-IE provides an opportunity for the delivery of addiction treatment, counseling, and harm reduction strategies.