Background: Prior studies show an association between drug use and health care utilization. The relationship between specific drug type and emergent/urgent, inpatient, outpatient, and behavioral health care utilization has not been examined. We aimed to determine if multiple drug use was associated with increased utilization of behavioral health care.
Methods: To assess health care utilization, we conducted a retrospective cohort study of patients who accessed health care at a safety-net medical center and affiliated clinics. Using electronic health records, we categorized patients who used stimulants, opioids, or multiple drugs based on urine toxicology screening tests and/or International Classification of Diseases, 9th Revision (ICD-9). Remaining patients were categorized as patients without identified drug use. Health care utilization by drug use group and visit type was determined using a negative binomial regression model. Associations were reported as incidence rate ratios. Utilization was described by rates of health care-related visits for inpatient, emergent/urgent, outpatient, and behavioral health care among patients who used drugs, categorized by drug types, compared with patients without identified drug use.
Results: Of 95,198 index visits, 4.6% (n=4340) were by patients who used drugs. Opioid and multiple drug users had significantly higher rates of behavioral health care visits than patients without identified drug use (opioid incidence rate ratio [IRR]=7.2; 95% confidence interval [CI]: 3.8-13.8; multiple drug use IRR=5.6, 95% CI: 3.3-9.7). Patients who used stimulants were less likely to use behavioral health services (IRR=1.3, 95% CI: 0.9-2.0) when compared with opioid and multiple drug users, but were more likely to use inpatient (IRR=1.6, 95% CI: 1.4-1.8) and emergent/urgent care (IRR=1.4, 95% CI: 1.3-1.5) services as compared with patients without identified drug use.
Conclusions: Integrated medical and mental health care and drug treatment may reduce utilization of costly health care services and improve patient outcomes. How to capture and deliver primary care and behavioral health care to patients who use stimulants needs further investigation.
Keywords: Health care; multiple drug use; opioid; stimulant; utilization.