Imaging Utilization and Cost of Substance Use in an Urban Academic Medical Center During the Contemporary Opioid Epidemic.

Rationale And Objectives: To determine the recent impact of illicit substance use on imaging utilization and associated costs.

Methods: Retrospective study from an inner city urban multi-site academic medical center. Institutional Review Board (IRB) approval was obtained with a waiver of informed consent. A substance use cohort comprised patients 12 years old presenting to the Emergency Department (ED) January 2017 to June 2019 with a positive urine toxicology and an ICD code associated with substance use. The comparison cohort was randomly selected from a group of ED patients who presented with no or negative urine toxicology and no documented substance use ICD code. Data extracted from the EMR included demographics, number and type of imaging studies, Charlson comorbidity index, and in-hospital mortality during the study period.

Results: The substance use and comparison cohorts comprised 3191 and 3200 patients, respectively. The substance use cohort was older on average (mean age 45.67 ± 14.88 vs 43.91 ± 20.57 years), more often male (63% [2026/3191] vs. 39% [1255/3200]) and had a mean Charlson score 88% higher than the comparison cohort (3.33 vs 1.78). The majority of both cohorts were ethnic minorities (<10% white). The substance use cohort had significantly more imaging vs the comparison cohort, total 36,413 (mean 11.41 exams/patient) vs total 12,399 (mean 3.87 exams/patient), p < 0.0001, and was higher for all modalities except mammography. Average imaging costs per patient were nearly 300% higher for the substance use vs comparison cohort, ($1287.18 vs. $434.70).

Conclusion: Imaging utilization and associated costs were substantially higher for patients with a positive urine toxicology and substance use related ICD codes compared to the broader ED population in an underserved urban population.