Cost-Effectiveness of Postoperative Drug Rehabilitation for Injection Drug Users

With the opioid crisis showing no sign of abating, strategies are needed to facilitate postoperative care for endocarditis related to injection drug use (IDU). The current standard, 6 weeks of intravenous antibiotics, yields frequent reoperation and IDU relapse. We examined the cost-effectiveness of inpatient drug rehabilitation (DR) postoperatively to optimize outcomes and costs.

Two postoperative strategies were assessed: hospital-only care (HC) vs HC plus inpatient DR. Monte Carlo simulation evaluated effectiveness in quality-adjusted life-years (QALY) and cost per patient calculated over a 20-year time horizon in 100,000 iterations. Willingness to pay was set to $100,000/QALY. To determine probabilities of continued postoperative IDU, recurrent infection, and death, best available evidence was combined with institutional data from IDU patients. Baseline probability of postoperative IDU was set to 35% after DR vs 60% after HC, and the cost of inpatient rehabilitation to $30,000.

Addition of inpatient DR to standard HC is the favorable strategy, with incremental per-patient cost of $36,920 and 0.93 QALYs gained over 20 years. Sensitivity analysis demonstrates DR is within our willingness-to-pay of $100,000/QALY if postoperative IDU is reduced by at least 7% (from 60% to 53%).

Addition of postoperative inpatient DR for IDU-related endocarditis is cost-effective even if only a modest reduction in IDU is achieved. Collaboration between hospitals and payors to launch pilot programs that provide postoperative addiction treatment and intravenous antibiotics after cardiac operations could dramatically improve endocarditis care.