Cost Effectiveness in Maintenance Management by lpe20000

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									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 Treatment                                    Page 1 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 Treatment                        Page 2 of 32
                       Introduction
   • 1-1.5 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 Treatment                           Page 3 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 Treatment                            Page 4 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 Treatment                        Page 5 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 Treatment                         Page 6 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 Treatment                          Page 7 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 Treatment                          Page 8 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 Treatment                          Page 9 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 Treatment                       Page 10 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 Treatment                          Page 11 of 32
           Simplest epidemic model
                        Uninfected        Infected
                       Persons, X(t)    Persons, Y(t)

  dY/dt = aY(t)[N + 1 - Y(t)]

  where: Y(0) = 1
                                        Y(t) = [N+1]/[1 + Ne-a(N+1)t]
          a = sufficient contact rate

          X(t) + Y(t) = N + 1


Number of Infected
Persons at Time t, Y(t)



                                                        t

Drug Abuse Treatment                                        Page 12 of 32
       Schematic of dynamic model
                        Not Infected    HIV-Infected    AIDS

                                         IDU,           IDU,
IDUs                       IDU
                                         HIV+           AIDS

 Methadone                                 IDU, MMT       IDU, MMT
 Maintenance                 IDU, MMT
                                             HIV+           AIDS
 Treatment

Non-IDUs                                Non-IDU        Non-IDU
                         Non-IDU
                                         HIV+           AIDS


 Drug Abuse Treatment                                     Page 13 of 32
                                                                                                

                                       9
                                       j(t)                                                     IDUs with AIDS,
             Uninfected IDUs,         j=1             HIV-Infected IDUs,                                                       
             Not in Treatment                          Not in Treatment                             Not in Treatment
                    X1(t)                                     X2(t)                                        X3(t)

    (t)      (t)                            (t)     (t)                        (t)       (t)

                                                                                                                  
                            (t)                                       (t)                                      (t)
                                              9




                                                                                                                                               AIDS Deaths
                   Uninfected IDUs,           j(t)            HIV-Infected IDUs,                          IDUs with AIDS,          
                                              j=1
                    In Treatment                                    In Treatment                                 In Treatment
                        X4(t)                                           X5(t)                                        X6(t)




                (t)      (t)                           (t)      (t)                        (t)        (t)
                                       9
               Uninfected             j(t)            HIV-Infected                             Non-IDUs                    
                                      j=1
                Non-IDUs                                    Non-IDUs                                  with AIDS
                  X7(t)                                       X8(t)                                      X9(t)


                                                                                                




Drug Abuse Treatment                                                                                                                   Page 14 of 32
                  Size of compartment 4                                       Epidemic model
                      (IDUs in MMT)
                                                                                    equations
Size of compartment 7           Size of compartment 1
 (general population)            (IDUs not in MMT)

                                                                                                              9
  X 1 (t )   71 (t ) X 7 (t )   41 (t ) X 4 (t )  X 1 (t )(17 (t )  14 (t )   1  1 )  X 1 (t ) 1 j (t )
                                                                                                              j 1




                Migration rates
                                                                                     Maturation
Change in number of                                                                                           New HIV
                                                                                        rate
 IDUs not in MMT                Mortality rate                                                                Infections

                                                                                                                  9
 X 2 (t )  82 (t ) X 8 (t )  52 (t ) X 5 (t )  X 2 (t )( 28 (t )   25 (t )   2   2   2 )  X 1 (t ) 1 j (t )
                                                                                                                j 1


    
 X 3 (t )  93 (t ) X 9 (t )  63 (t ) X 6 (t )   2 X 2 (t )  X 3 (t )(39 (t )  36 (t )   3  3   3 )
                                                                                                                               etc...
        Drug Abuse Treatment                                                                                 Page 15 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 Treatment                             Page 16 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 Treatment                        Page 17 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 Treatment                           Page 18 of 32
               Cost and quality of life
                                      HIV-
                       Uninfected   Infected   AIDS

   Untreated            $3,850      $8,653     $36,401
   IDUs                  (.80)       (.72)      (.42)
   MMT                  $8,261      $18,806    $40,812
                         (.90)       (.81)      (.48)
   Non-IDUs             $1,210      $6,013     $33,761
                        (1.00)       (.90)      (.53)


Drug Abuse Treatment                               Page 19 of 32
                  Results:
            Methadone maintenance
                       High-Prevalence Low-Prevalence
                         Community       Community
      Methadone cost      $17.0 m          $4.8 m

      Net cost            $10.9 m          $3.3 m

      QALYs gained          1300            301

      CE ratio             $8,200         $10,900



Drug Abuse Treatment                              Page 20 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 Treatment                                Page 21 of 32
  Cost of 100 new slots ($1000’s)
                          High-Prevalence Low-Prevalence
                            Community       Community
Methadone                      4538           4538

HIV care – IDUs                -970            -540

HIV care – non-IDUs            -321            -323

Other health – IDUs            -569            -796

Other health – non-IDUs        241             242

Total cost                     2919           3121
Drug Abuse Treatment                            Page 22 of 32
Benefits of 100 new slots ($1000’s)
                                High-Prevalence Low-Prevalence
                                  Community       Community

Infections averted – IDUs             51               20

Infections averted – non-IDUs         19               12

QALYs – IDUs                         149               81

QALYs – former IDUs                   28               46

QALYs – never IDUs                   178              160


  Drug Abuse Treatment                              Page 23 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 Treatment                          Page 24 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 Treatment                        Page 25 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 Treatment                            Page 26 of 32
                CE ratios:
        Buprenorphine maintenance
                             $5/Dose   $15/Dose $30/Dose
All Slots incremental:
 High-prevalence community   $10,800   $20,500      $35,000
 Low-prevalence community    $14,000   $26,000      $44,200
5% Net Expansion:
 High-prevalence community   $14,000   $35,100      $66,700
 Low-prevalence community    $17,700   $44,500      $84,700

 Drug Abuse Treatment                            Page 27 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 Treatment                             Page 28 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 Treatment                          Page 29 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 Treatment                         Page 30 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 Treatment                        Page 31 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



Drug Abuse Treatment                     Page 32 of 32

								
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