Purpose: Vaccine cross-protection and the tendency to offer free-of-charge vaccination to older women demand a new evaluation of the cost-effectiveness of cervical screening and HPV vaccination in Italy.
Method: In Italy the non-mandatory vaccination is available free of charge to preadolescent girls. Each region has its own vaccination program in addition to the national one. We used our previously developed Markov model to describe the natural history of HPV infections and carcinogenesis of cervical cancer. The model was calibrated to fit to empirical age-specific HPV prevalence and incidence of cervical cancer observed in Italy. We simulated 10 million individual life histories using a Monte Carlo micro simulation. If the simulated woman undergoes a preventive strategies her life history can change. These changes represent the effects of the intervention. Strategies are defined by varying the type of first screening test, use of triage, the frequency of the screening program, screening age. Each scenario was evaluated without vaccination, with vaccination at age 11 years or 25 years. Vaccine assumptions: 100% coverage, 75.6% effective against HPV 16/18 infection, and 11% effective against high-risk HPV non 16/18. We compared alternatives strategies using incremental cost-effectiveness ratio (ICER). Discount rate was 3%.
Result: Vaccination at age 25 years was always dominated by strategies without vaccination.
| Preventive strategy | Vaccine | Screening frequency (yrs) | Screening age | ICER (EURO) |
| No screening, non vaccine | No | - | - | - |
| HPV DNA test+Pap test triage | No | 7 | 30 to 65 (to 50 for negative women) | 3269 |
| HPV DNA test+Pap test triage | No | 7 | 30 to 65 | 6581 |
| HPV DNA test+Pap test triage | Yes | 9 | 25 to 65 | 12656 |
| HPV DNA test+Pap test triage | Yes | 7 | 30 to 65 | 13617 |
| HPV DNA test+Pap test triage | Yes | 5 | 30 to 65 (to 50 for negative women) | 31982 |
| HPV DNA test+Pap test triage | Yes | 3 | 30 to 65 (to 50 for negative women) | 151732 |
Conclusion: Under the assumption that vaccination is ineffective in previous infected women, HPV vaccination in women aged 25 years is highly questionable and cost-ineffective. The prolongation of screening interval as well as narrowing the screening age range for women vaccinated at 11 years of age may be acceptable.