Purpose: U.S.-based physicians with appropriate training may prescribe buprenorphine-naloxone (BPN) to treat opioid dependence in office-based settings, where many patients prefer to be treated. U.S. patent exclusivity for BPN ends in October 2009. We evaluated the cost-effectiveness of long-term office-based BPN treatment for clinically stable patients compared to no treatment, and the value of additional research, under alternative drug pricing scenarios.
Methods: A decision analytic model simulated a cohort of clinically stable opioid dependent individuals, who have already completed six months of office-based BPN treatment. Data were from a published cohort study reporting retention in treatment and opioid use with median 13.4 months follow-up. Outcomes included patient and provider costs in 2006 U.S. dollars, quality adjusted life years (QALYs), and incremental cost-effectiveness (CE) ratios ($/QALY); costs and QALYs were discounted at 3% annually. Uncertainty in estimated monthly costs (from the cohort) and utilities (from a U.K. study) were evaluated in probabilistic sensitivity analyses (10,000 simulations), and we calculated the expected value of partial perfect information (EVPPI) for utilities and costs with two-level simulations (1000 inner loops and 100 outer loops).
Results: In the base case, office-based BPN has a CE ratio of $44,100/QALY compared to no treatment after 24 months, and $30,800/QALY after 60 months, with 56% and 58% of simulations below $100,000/QALY respectively. With BPN price reductions due to generic competition, CE ratios are lower but model uncertainty remains (see table). At a threshold of $100,000/QALY, EVPPI/person is $14,300 for utilities and $100 for costs after 24 months ($759,000 and $5,300 for the cohort); EVPPIs are similar with lower BPN prices.
| Scenario | Incremental Cost ($) | Incremental QALY | Incremental CE Ratio ($/QALY) | % Simulations <$100K/QALY |
| 24-month outcomes | ||||
| Base case | $5,361 | 0.12 | $44,100 | 56% |
| BPN price reduced 20% | $4,653 | 0.12 | $38,100 | 57% |
| BPN price reduced 50% | $3,545 | 0.12 | $29,200 | 59% |
| 60-month outcomes |
|
|
|
|
| Base case | $8,583 | 0.28 | $30,800 | 58% |
| BPN price reduced 20% | $7,420 | 0.28 | $26,600 | 58% |
| BPN price reduced 50% | $5,676 | 0.28 | $20,400 | 59% |
Conclusion: Office-based BPN for clinically stable patients is a cost-effective alternative to no treatment at a threshold of $100,000/QALY. Even if BPN prices fall due to generic competition, the value of collecting additional data about utilities on and off BPN therapy is high compared to the cost of this research.
Candidate for the Lee B. Lusted Student Prize Competition