Abstract:
Cytology remains the mainstay of cervical cancer screening in South Africa (SA), however
false negative rates are 25–50%. In contrast, human papillomavirus (HPV) screening techniques
have higher sensitivity for cervical cancer precursors. The cobas® 4800 HPV test
detects pooled high-risk HPV types and individual genotypes HPV 16 and 18. Using a mathematical
budget impact model, the study objective was to evaluate the clinical and budget
impact of replacing primary liquid-based cytology (LBC) with primary HPV-based screening
strategies. In SA, current LBC screening practice recommends one test every ten years, followed
by large loop excision of the transformation zone (LLETZ) if indicated. HPV testing
can be performed from an LBC sample, where no additional consultations nor samples are
required. In the budget impact model, LBC screening for 2 cycles (one test every ten years)
was compared to cobas® 4800 HPV test for 2 cycles (one test every 5 years). The model
inputs were gathered from literature and primary data sources. Indicative prices for LBC and
cobas® 4800 HPV test were R189 and R457, respectively. Model results indicate that best
outcomes for detection of disease were seen using cobas® 4800 HPV test. Forty-eight percent
of cervical cancer cases were detected compared to 28% using LBC, and 50% of cervical
intraepithelial neoplasia (CIN) 2 and CIN3 cases, compared to 25% with LBC. The
budget impact analysis predicted that the cost per detected case of CIN2 or higher would be
R 56,835 and R46,980 for the cobas® 4800 HPV and LBC scenarios, respectively. This
equates to an incremental cost per detected case of CIN2 or higher of R9 855. From this model we conclude that a primary HPV screening strategy will have a significant clinical
impact on disease burden in South Africa.
