Borderline and mildly dyskaryotic smears (BMD) are the most common type of cervical cytologic abnormalities. In the Netherlands, women are triaged to colposcopy only when BMD does not normalize within 6 months, but this nevertheless induces a considerable amount of negative side effects (unnecessary referrals and treatment, anxiety). An infection with an oncogenic type of human papillomavirus (HPV) is a necessary factor in progression to invasive cervical cancer. HPV can be detected in about one half of the persistent BMD. We assessed expected costs and negative side effects for three different HPV triage strategies of women with persistent BMD, and compared them to the current standard practice of referring all women with a persistent BMD regardless of HPV status.
The following HPV triage strategies: A – immediate referral of all HPV+ women at baseline (i.e., shortly after the second BMD smear), B – immediate referral of all women HPV+ 6 months after baseline, and C – follow-up of women HPV+ at baseline, with an immediate referral if still HPV+ after 6 months, were compared to the current standard practice. The expected average costs and negative side effects were calculated through the percent of women testing HPV+ at different time points, the cervical intraepithelial neoplasia distribution, and post-referral abnormality rates. Epidemiologic input parameters were observed in a clinical trial performed at our medical center. Unit costs reflect the recent Dutch practice.
Triaging women with persistent BMD based on detecting HPV is less expensive than the current standard practice. Regardless of the HPV strategy analyzed, fewer women need to undergo treatment and on average remain in follow-up for a shorter period of time. Among the HPV strategies, strategy B is the cheapest, followed by strategies C and A, respectively. On average, women are kept in follow-up the shortest time under strategy A. A sensitivity analysis showed that these findings are robust to uncertainties in the data.
HPV triage strategies of persistent BMD that rely on clearance of the HPV within a relatively short period (e.g., within 6 months in strategies B and C) enjoy a cost advantage over strategies which immediately refer all/HPV+ women, but those that act on HPV infection earlier (e.g., strategy A) have a higher potential to reduce the negative side effects.