Drug Abuse TreatmentPage 1 of 32 Cost Effectiveness of Maintenance Treatment for Heroin Addicts Professor Margaret Brandeau Department of Management Science and Engineering with Greg Zaric, U. Western Ontario Paul Barnett, Palo Alto VA

Drug Abuse TreatmentPage 2 of 32 Outline of Talk Background Model of maintenance therapy for opiate addiction and HIV prevention Results – methadone Results – buprenorphine Other relevant issues

Drug Abuse TreatmentPage 3 of 32 Introduction million IDUs in U.S. High prevalence of HIV among IDUs (5-40%) One-third of new HIV cases due to IDUs New laws require treatment instead of jail time

Drug Abuse TreatmentPage 4 of 32 Methadone maintenance Addicts receive daily doses of methadone Methadone treatment slots only for 15% of IDUs Average wait to enter treatment is 6 months Expansion of MMT is controversial Many health care sponsors (e.g., Medicaid) do not cover MMT Eight states prohibit methadone

Drug Abuse TreatmentPage 5 of 32 Methadone in the news “Mayor Wants To Abolish Use of Methadone” “Methadone: A Cure or an Addiction?; Giuliani Is Right” “Few Successes to Back Mayor’s Methadone Limits” (NY Times, 8/25/98) “Federal Proposal Would Provide Methadone to More Drug Addicts” (NY Times, 9/29/98)

Drug Abuse TreatmentPage 6 of 32 Buprenorphine maintenance Buprenorphine may be safer than methadone Low abuse potential; daily dispensing not required Less effective than methadone in reducing risky behavior Widely used in France Not approved for maintenance treatment in U.S. No price set

Drug Abuse TreatmentPage 7 of 32 Potential benefits of maintenance treatment Reduced HIV transmission Reduced mortality and comorbidities associated with injection drug use Increased quality of life Reductions in cost of HIV care and other health care Reductions in cost of social programs

Drug Abuse TreatmentPage 8 of 32 Potential drawbacks of maintenance treatment Maintenance treatment is costly - $5,000+ / year HIV-infected individuals in maintenance treatment are more likely to receive expensive HIV treatment Maintenance treatment does not induce complete abstinence from risky behavior Average stay in treatment is 2 years 90% of those leaving treatment resume injection drug use!

Drug Abuse TreatmentPage 9 of 32 Policy questions What is the cost effectiveness of expanding existing methadone maintenance programs in the U.S.? What would be the cost effectiveness of buprenorphine maintenance treatment in the U.S., as a function of its price?

Drug Abuse TreatmentPage 10 of 32 Methods Dynamic model of HIV transmission Two scenarios: High (40%) and low (5%) HIV prevalence among IDUs Assumed modest increases in maintenance treatment capacity –Methadone: 10% increase –Buprenorphine: 10% increase All slots incremental 5% net expansion

Drug Abuse TreatmentPage 11 of 32 Methods (cont.) Estimated total costs and health benefits over a 10-year time horizon (societal perspective) Costs: all health care costs Benefits: QALYs gained Calculated incremental CE ratios

Drug Abuse TreatmentPage 12 of 32 Uninfected Persons, X(t) Infected Persons, Y(t) dY/dt = aY(t)[N Y(t)] where: Y(0) = 1 a = sufficient contact rate X(t) + Y(t) = N + 1 Y(t) = [N+1]/[1 + Ne -a(N+1)t ] t Number of Infected Persons at Time t, Y(t) Simplest epidemic model

Drug Abuse TreatmentPage 13 of 32 Schematic of dynamic model Non-IDU HIV+ Non-IDU AIDS IDU IDU, MMT IDU, HIV+ IDU, AIDS IDU, MMT HIV+ IDU, MMT AIDS Not InfectedHIV-InfectedAIDS IDUs Methadone Maintenance Treatment Non-IDUs

Drug Abuse TreatmentPage 14 of 32 Uninfected IDUs, Not in Treatment X 1 (t)          (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t)   (t) Uninfected IDUs, In Treatment X 4 (t) Uninfected Non-IDUs X 7 (t) HIV-Infected IDUs, Not in Treatment X 2 (t) HIV-Infected IDUs, In Treatment X 5 (t) HIV-Infected Non-IDUs X 8 (t) IDUs with AIDS, Not in Treatment X 3 (t) IDUs with AIDS, In Treatment X 6 (t) Non-IDUs with AIDS X 9 (t)     AIDS Deaths                                   j (t) j=1 9   j (t) j=1 9   j (t) j=1 9

Drug Abuse TreatmentPage 15 of 32 etc... Size of compartment 7 (general population) Migration rates Size of compartment 4 (IDUs in MMT) Size of compartment 1 (IDUs not in MMT) Mortality rate Maturation rate New HIV Infections Change in number of IDUs not in MMT Epidemic model equations

Drug Abuse TreatmentPage 16 of 32 Model inputs Drug injection behavior (in/out of treatment) Sexual behavior HIV transmission rates HIV progression rates Mortality rates Quality-of-life estimates Cost per maintenance treatment slot All other health care costs

Drug Abuse TreatmentPage 17 of 32 Methadone assumptions Methadone maintenance cost: $5250/IDU/year Methadone maintenance effectiveness: –80% reduction in injection frequency –70% reduction in sharing –65% annual retention rate –3.5% annual graduation rate

Drug Abuse TreatmentPage 18 of 32 Other data Non-HIV death rates Untreated IDUs – 3% IDUs in MMT – 1.13% Non-IDUs –.14% Progression rates from HIV to AIDS Untreated IDUs, and non-IDUs –.0087 IDUs in MMT –.0082

Drug Abuse TreatmentPage 19 of 32 Cost and quality of life

Drug Abuse TreatmentPage 20 of 32 Results: Methadone maintenance

Drug Abuse TreatmentPage 21 of 32 CE of other HIV interventions HIV treatments (cost/QALY gained) –PCP prophylaxis: $16,000 –MAC prophylaxis: $35,000-$74,000 –CMV retinitis prophylaxis: $160,000 HIV prevention –Post-exposure prophylaxis: $37,000 after occupational exposure; $6,300 after sexual exposure –Incr. condom use among high-risk women: $2,000 –Skills training for gay men: Cost saving

Drug Abuse TreatmentPage 22 of 32 Cost of 100 new slots ($1000’s)

Drug Abuse TreatmentPage 23 of 32 Benefits of 100 new slots ($1000’s)

Drug Abuse TreatmentPage 24 of 32 Results of sensitivity analysis MMT cost effective even if: New slots are twice as costly and half as effective as existing slots No reduction in quality of life for IDUs IDUs receive a quality-of-life adjustment of zero Only life years are measured

Drug Abuse TreatmentPage 25 of 32 Conclusions: Methadone maintenance Expansion of methadone maintenance treatment is cost effective relative to commonly accepted criteria Significant benefits of methadone maintenance programs accrue to non-IDUs Barriers to methadone maintenance may restrict access to a cost-effective medical intervention

Drug Abuse TreatmentPage 26 of 32 Buprenorphine assumptions Buprenorphine maintenance cost: –$5700, $9400, $14,900/IDU/year Buprenorphine maintenance effectiveness: –73% reduction in injection frequency –64% reduction in sharing –65% annual retention rate –2.8% annual graduation rate

Drug Abuse TreatmentPage 27 of 32 CE ratios: Buprenorphine maintenance

Drug Abuse TreatmentPage 28 of 32 Results of sensitivity analysis Buprenorphine cost effective if: –High value assigned to treatment benefit –Low value for treatment benefit, low price Buprenorphine not cost effective if: –No value assigned to LYs of IDUs or those in treatment, and high price –Many IDUs switch from MMT to buprenorphine

Drug Abuse TreatmentPage 29 of 32 Conclusions: Buprenorphine maintenance At $5/dose, buprenorphine maintenance treatment is cost effective Buprenorphine is cost effective at $15/dose only if its adoption does not lead to a decline in MMT Buprenorphine is not likely to be cost effective if the price is $30/dose

Drug Abuse TreatmentPage 30 of 32 Other relevant issues Reductions in cost of social programs Reductions in spread of other diseases (Hepatitis B and C, TB, other STDs) Networks of IDUs Characteristics of IDUs enrolled in the incremental treatment slots Legal, philosophical and moral concerns

Drug Abuse TreatmentPage 31 of 32 Update MMT programs –Expansion in some areas –Budget cutbacks in some states –“Wait for Methadone Puts Hundreds of Lives on Hold” (Seattle PI, 3/17/03)

Drug Abuse TreatmentPage 32 of 32 Update Buprenorphine approved by FDA in October, 2002 –Schedule III drug –Prescribed in doctor’s office –30-day prescriptions –Cost/dose ~ $5 –Medicare coverage: on a state-by-state basis