Kine Pedersen

Vaccination and screening strategies to accelerate cervical cancer elimination in Norway: a model-based analysis

Experts have proposed an 'EVEN FASTER' concept targeting age-groups maintaining circulation of human papillomavirus (HPV). We explored effects of the vaccination component of these proposals compared with cervical cancer (CC) screening-based interventions on age-standardized incidence rate (ASR) and CC elimination (<4 cases/100,000) timing in Norway. We used a model-based approach to evaluate HPV vaccination and CC screening scenarios compared with a status-quo scenario reflecting previous vaccination and screening. For cohorts ages 25-30 years, we examined 6 vaccination scenarios that incrementally increased vaccination coverage from current cohort-specific rates. Each vaccination scenario was coupled with three screening strategies that varied screening frequency. Additionally, we included 4 scenarios that alternatively increased screening adherence. Population- and cohort-level outcomes included ASR, lifetime risk of CC, and colposcopy referrals. Several vaccination strategies coupled with de-intensified screening frequencies lowered ASR, but did not accelerate CC elimination. Alternative strategies that increased screening adherence could both accelerate elimination and improve ASR. The vaccination component of an 'EVEN FASTER' campaign is unlikely to accelerate CC elimination in Norway but may reduce population-level ASR. Alternatively, targeting under- and never-screeners may both eliminate CC faster and lead to greater health benefits compared with vaccination-based interventions we considered.

Switching clinic‐based cervical cancer screening programs to human papillomavirus self‐sampling: A cost‐effectiveness analysis of vaccinated and unvaccinated Norwegian women

AbstractSeveral countries have implemented primary human papillomavirus (HPV) testing for cervical cancer screening. HPV testing enables home‐based, self‐collected sampling (self‐sampling), which provides similar diagnostic accuracy as clinician‐collected samples. We evaluated the impact and cost‐effectiveness of switching an entire organized screening program to primary HPV self‐sampling among cohorts of HPV vaccinated and unvaccinated Norwegian women. We conducted a model‐based analysis to project long‐term health and economic outcomes for birth cohorts with different HPV vaccine exposure, that is, preadolescent vaccination (2000‐ and 2008‐cohorts), multiage cohort vaccination (1991‐cohort) or no vaccination (1985‐cohort). We compared the cost‐effectiveness of switching current guidelines with clinician‐collected HPV testing to HPV self‐sampling for these cohorts and considered an additional 44 strategies involving either HPV self‐sampling or clinician‐collected HPV testing at different screening frequencies for the 2000‐ and 2008‐cohorts. Given Norwegian benchmarks for cost‐effectiveness, we considered a strategy with an additional cost per quality‐adjusted life‐year below $55 000 as cost‐effective. HPV self‐sampling strategies considerably reduced screening costs (ie, by 24%‐40% across cohorts and alternative strategies) and were more cost‐effective than clinician‐collected HPV testing. For cohorts offered preadolescent vaccination, cost‐effective strategies involved HPV self‐sampling three times (2000‐cohort) and twice (2008‐cohort) per lifetime. In conclusion, we found that switching from clinician‐collected to self‐collected HPV testing in cervical screening may be cost‐effective among both highly vaccinated and unvaccinated cohorts of Norwegian women.

Cost‐effectiveness of primary human papillomavirus triage approaches among vaccinated women in Norway: A model‐based analysis

AbstractAs Norway considers revising triage approaches following their first adolescent cohort with human papillomavirus (HPV) vaccination entering the cervical cancer screening program, we analyzed the health impact and cost‐effectiveness of alternative primary HPV triage approaches for women initiating cervical cancer screening in 2023. We used a multimodeling approach that captured HPV transmission and cervical carcinogenesis to evaluate the health benefits, harms and cost‐effectiveness of alternative extended genotyping and age‐based triage strategies under five‐yearly primary HPV testing (including the status‐quo screening strategy in Norway) for women born in 1998 (ie, age 25 in 2023). We examined 35 strategies that varied alternative groupings of high‐risk HPV genotypes (“high‐risk” genotypes; “medium‐risk” genotypes or “intermediate‐risk” genotypes), number and types of HPV included in each group, management of HPV‐positive women to direct colposcopy or active surveillance, wait time for re‐testing and age at which the HPV triage algorithm switched from less to more intensive strategies. Given the range of benchmarks for severity‐specific cost‐effectiveness thresholds in Norway, we found that the preferred strategy for vaccinated women aged 25 years in 2023 involved an age‐based switch from a less to more intensive follow‐up algorithm at age 30 or 35 years with HPV‐16/18 genotypes in the “high‐risk” group. The two potentially cost‐effective strategies could reduce the number of colposcopies compared to current guidelines and simultaneously improve health benefits. Using age to guide primary HPV triage, paired with selective HPV genotype and follow‐up time for re‐testing, could improve both the cervical cancer program effectiveness and efficiency.