Evidence to Support Change of Clinical Pathway Following Colposcopy Treatment for Cervical Intraepithelial Neoplasia in Canada.

Objectives: Human papillomavirus (HPV) testing can be incorporated into the post-treatment pathway of cervical intraepithelial neoplasia (CIN) to confirm disease-free status. To inform a post-treatment strategy based on risk of recurrence, we modelled disease and economic outcomes.

Methods: The current Alberta, Canada, post-treatment care pathway-cytology testing with colposcopy assessment-was compared with 6 other scenarios incorporating cytology, HPV testing, or both tests at different time points in a modelling study based on a microsimulation program. Input parameter values for the screening participation, screening age groups, and follow-up options and test compliance for HPV, cytology, and colposcopy were varied, based on Alberta cervical cancer screening program data. Health outcomes over the short- and long-term were projected, which incorporated the increasing population-level coverage of HPV vaccination. Lifetime incremental cost-effectiveness ratios (ICERs) were used to evaluate economic outcomes and descriptive statistics compared with numbers of tests, visits, and procedures as well as changes in incidence and mortality rates between the scenarios.

Results: At 5 years after implementation of the "HPV testing alone at 6 and 18 months" post-treatment pathway, the number of colposcopies dropped by 36% and the number of pre-cancer treatments, by 6%. Lifetime ICERs were CAD $6170 versus $248,495 per quality-adjusted life-year compared with the status quo pathway. Cervical cancer incidence and mortality rates decreased significantly and similarly in all scenarios.

Conclusion: Strategies that involve HPV testing in CIN post-treatment follow-up care are expected to be more cost effective with improved clinical outcomes than traditional cytology and colposcopy-based follow-up.