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					Cost Effectiveness of a Human Papillomavirus Vaccine in
  reducing the risk of cervical cancer in Ireland using a
              transmission dynamic model.



Cara Usher1, Lesley Tilson1, Cathal Walsh2, Jens Olsen3, Martin Rudbeck
                        Jepsen4, Michael Barry1.


    1. National Centre for Pharmacoeconomics, Dublin, Ireland.
    2. Dept. of Statistics, Trinity College Dublin, Ireland.
    3. University of Southern Denmark, Odense, Denmark.
    4. Statens Serum Institut, Copenhagen, Denmark.
Aim

 To evaluate the cost effectiveness of a combined primary
   (vaccination) and secondary (screening) approach to
     managing pre-cancerous and cancerous lesions
                             vs
 A population-based cervical cancer screening programme
                     alone in Ireland.
       Human Papilloma Virus (HPV)
More than 100 different types of HPV infection have
been characterised:
– High risk – most common are HPV 16, 18, 45 and 31.


– Low risk- include HPV types 6, 11.




                                   Cause ~70% of
            Cause ~ 90% of         cervical cancers
            anogenital warts
      Human Papilloma Virus (HPV) Vaccine
   Two vaccines currently developed:
       1.Gardasil® – protects against HPV types 16, 18, 6 and 11.
       2.Cervarix ® – protects against HPV types 16 and 18.


   Efficacy demonstrated for up to 5.5 years after vaccination.


   Requirement for booster dose at later time not established.


Routine cytology screening still required, as vaccines do not protect
against all oncogenic types of HPV.
        Natural history of HPV


                Infection                  Progression
Normal Cervix               HPV infected                 CIN 2/3   Cancer
                              Cervix

                              (CIN 1)
                Clearance                  Regression
                       Methods

Framework
• Scope of analysis agreed with economic modelling group
in Denmark and EAG in Ireland.

Comparator
• Population-based cervical cancer screening programme

Perspective
• Healthcare payer
                               Model Structure


     Transmission model                          Cost Effectiveness Model
Simulated infection caused                  Outputs from transmission model
by HPV 16&18 only, using sexual             combined with resource use and
    behaviour patterns1.                    cost data

HPV type-specific prevalence                Incremental effects
- Artistic trial2.                          ( incidence CIN 1-3, CC)

Calibration: Estimates CIN1-3,              Incremental costs
    CC incidence                            (costs of vaccination vs no
                                            vaccination)
1.    Layte et al, 2006.
2.    Kitchener et al, 2006.
                 Model Inputs

• Epidemiological data

          • Sexual behaviour patterns
          • HPV-type distribution
          • Prevalence of HPV infection
          • Incidence of premalignant and invasive CC

• Resource use data

          • Vaccination costs
          • Direct medical costs
          • Unit cost data
                  Model Inputs
• Time Horizon

         • 70 yrs (9 – 79 years)
• Outcome Measure

         • Life Years Gained
• Vaccine Coverage

         • 80% (based on Men C catch-up programme).
• Discounting

         • 3.5% costs & benefits
Scenario                Coverage

12 yr old females            80%

12 yr olds + catch-up        80%
to 15 yrs
12 yr olds + catch-up        80%
to 17 yrs
12 yr olds + catch-up        80%
to 19 yrs
12 yr olds + catch-up        80%
to 26 yrs                    30% (GP)
Model Inputs   Vaccine efficacy                 95.2%
(Summary)      Duration of vaccine protection   Lifelong
               Screening                        25-44 yrs, 80% screened every
                                                3 yrs
                                                45-60 yrs, 80% screened every
                                                5 yrs
               Proportion of CIN 1-3 caused     74% CC
               by HPV 16 & 18                   50% CIN 2/3, 35% CIN 1
               Cost of vaccine                  €100

               Administration costs             €30 (<19 yrs)
                                                €58 (>19 yrs)
               Direct Medical Costs
               • CIN 1                          €617
               • CIN 2/3                        €1,632
               • Invasive cancer                €18,160
               Discount Rate                    3.5% (costs & benefits)
Parameter                         One-Way SA    Probabilistic SA
Vaccine Efficacy                  88% - 99%     Beta (35, 2)
Duration of vaccine protection    10            Bernoulli (0, 5)
                                  yrs/booster
Vaccine Coverage                  60%           Beta (20, 5)
Screening                         62%           Beta (20, 5)
Proportion of CIN 1-3 and CC      60% CC        Beta (60, 20) CC
caused by HPV 16 / 18             40% CIN 2/3   CIN 2/3 in proportion
                                  21% CIN 1     CIN 1
Cost of vaccine (per dose)        €80 - €120    N (100, 10)
Administration costs (per dose)   €15 - €45     N(30, 7) truncated to be +ive
Direct Medical Costs               20%          N (0, 0.1)
Discount rate                     0 and 6%      Triangular (0, 3.5, 6%)
  Results (1) – Simulation Model


                       4.5
Female Incidence [%]




                        4
                                                                                        No vaccination HPV16
                       3.5

                        3
                                                                                        No vaccination HPV18
                       2.5                                                              Base case HPV16
                        2                                                               Base case HPV18
                       1.5                                                              HPV16 catch-up
                         1
                                                                                        HPV18 catch-up
                       0.5

                        0
                                 12
                                      18
                                           24
                                                30
                                                     36
                                                          42
                                                               48
                                                                    54
                                                                         60
                                                                              66
                                                                                   72
                       0
                             6




                                       Time from intervention
Results (2) – Cases Averted

     Health         Estimated total     Average annual
     state         number of cases in   number of cases
                         2004            averted due to
                                        HPV vaccination
     CIN 1             7,259              2,245


     CIN2/3            3,515              1,435


     Cervical           200                 111
     cancer

     Deaths from         93                  52
     cervical
     cancer
Results (3) – Cost Effectiveness of the base-case
                       vaccination programme
             (HPV vaccination & screening vs screening alone)


    Incremental costs    Incremental life
      (discounted)                               ICER
                           years gained
                           (discounted)



       € 6,984,496         401.8 years       € 17,383 / LYG
Results (3) – Cost Effectiveness of catch-up vaccination
                             programmes
                               12

                               11
                                                                                                        Scenario 5    ICER €24,534/LYG
                               10
                                                                                                       Scenario 4    ICER €22,038/LYG
  Incremental cost million €




                               9

                               8
                                                                                                       Scenario 3
                                                                                                                     ICER €20,646/LYG
                                                                                                      Scenario 2
                                                                                                                   ICER €18,893/LYG
                               7
                                                                                                   Scenario 1   ICER €17,383/LYG
                               6

                               5

                               4

                               3

                               2

                               1
                                        No vaccination
                               0
                                    0   50         100   150     200     250     300   350   400         450

                                                               Incremental LYG




12 yr olds + Catch-Up to 15 yrs: ICER €52,968/LYG.
Results (4) – Sensitivity Analysis: Probabilistic




                                 97.5 centile




       2.5 centile
Results (5) – Sensitivity Analysis: One-Way
            €17,383/LYG              Population screening coverage (62%)

                                                  Proportion caused by HPV 16/18 (60% Cervical
                                                  cancer, 40% CIN 2/3, 21% CIN 1)
                                      Vaccine efficacy (85-99%)

                                                             Booster dose at 10 years

                                     Vaccine coverage (60%)

                                             Cost of administration of vaccine (15-45 per dose)

                                              Cost of vaccine (80-120 per dose)

                                        Direct medical Costs (+/-20%)
                                                                              Discount rate (0-6%)

        0     5000   10000   15000   20000      25000   30000     35000   40000    45000

                                        ICER
Summary


• Cost-effectiveness of base-case vaccination programme
                   ICER €17,383/LYG


• Cost-effectiveness of catch-up vaccination programmes
            ICER €52,968/LYG (12-15 yr olds)
Strengths / Limitations

• Study framework, i.e. a collaborative approach to assessing
cost-effectiveness of an intervention in a short timeframe.

• Uncertainty with data.
      • cross-protection
      • requirement for booster
      • vaccine efficacy against types 6 & 11
Conclusions

• Epidemiological impact of vaccination

• Cost effective to vaccinate 12 yr old females

• Cost effective to vaccinate 12 – 15 yr old females
  5th August 2008

Minister for Health Approves Introduction Of Cervical Cancer
                   Vaccination Programme


 “It is clear the main priority now is to move to the introduction of
 the vaccination programme for 12 year old girls to commence in
                          September 2009” .
Acknowledgements

				
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