Optimizing Cervical Cancer Screening by Age at Vaccination for Human Papillomavirus: Health and Resource Implications.

BACKGROUND

Widespread vaccination for human papillomavirus (HPV) alters the landscape of cervical cancer (CC) risk, requiring adaptations to the CC screening program.

OBJECTIVE

To assess the cost-effectiveness and harm-benefit tradeoffs of adapting CC screening strategies on the basis of age at HPV vaccination.

DESIGN

Individual-based mathematical modeling study.

DATA SOURCES: Published data.

TARGET POPULATION: Hypothetical cohorts of women vaccinated in 7 different age groups (12, 13 to 15, 16 to 18, 19 to 21, 22 to 24, 25 to 27, and 28 to 30 years) with either bivalent or nonavalent vaccines in Norway.

TIME HORIZON: Lifetime.

PERSPECTIVE: Extended health care sector (that is, including patient time and travel costs).

INTERVENTION: HPV-based screening strategies that varied screening start age, interval, and number of lifetime screening tests.

OUTCOME MEASURES: Incremental cost-effectiveness ratios, defined as the additional cost per quality-adjusted life-year (QALY) gained. "Preferred" (that is, cost-effective) screening for each age group was identified using a cost-effectiveness threshold of $55 000 per QALY. Harm-benefit tradeoffs were quantified as the ratio of colposcopy referrals to CC cases averted.

RESULTS OF BASE-CASE ANALYSIS: For all vaccination age groups and both vaccines, less frequent screening with longer intervals between screening than the 5-year interval currently recommended was consistently preferred at the threshold of $55 000 per QALY, but the preferred strategy varied by age at vaccination. For women vaccinated between ages 12 and 24 years, preferred strategies involved screening every 15 to 25 years, resulting in screening 2 to 3 times per lifetime.

RESULTS OF SENSITIVITY ANALYSIS: Less frequent screening remained a preferred strategy under imperfect screening adherence and in scenarios that excluded bivalent vaccine cross-protection.

LIMITATION: The analysis did not address screening for unvaccinated women, who may benefit from herd immunity.

CONCLUSION

A high-value screening program likely involves less frequent screening for women who were vaccinated against HPV by age 30 years. Strategies could be tailored on the basis of age at vaccination and type of HPV vaccine.

PRIMARY FUNDING SOURCE: Norwegian Cancer Society and National Cancer Institute.