Background: Benefits of screening should outweigh its potential harms. We compared various metrics to assess the balance of benefits and harms of cervical cancer screening. Methods: We used a cervical cancer natural history Markov model calibrated to the Canadian context to simulate 100,000 unvaccinated women over a lifetime of screening with either cytology every 3 years or human papillomavirus (HPV) testing every 5 years. We estimated the balance of benefits and harms attributable to screening using various metrics, including colposcopies/life-year gained, and net lifetime quality-adjusted life-years (QALY) gained, a measure integrating women's health preferences. We present the average (minimum–maximum) model predictions. Results: Cytology-based screening led to 1,319,854 screening tests, 30,395 colposcopies, 13,504 life-years gained over a lifetime, 98 screening tests/life-year gained, 2.3 (1.6–3.3) colposcopies/life-year gained, and a net lifetime gain of 10,735 QALY (5,040–17,797). HPV-based screening with cytology triage in the same population would lead to 698,250 screening tests, 73,296 colposcopies, 15,066 life-years gained over a lifetime, 46 screening tests/life-year gained, 4.9 colposcopies/life-year gained (2.9–11.1), and a net lifetime gain of 11,690 QALY (4,409–18,742). HPV-based screening was predicted to prevent more cancers, but also incur more screening harms than cytology-based screening. Conclusions: Metrics using colposcopies as the main harm outcome favored cytology-based screening, whereas metrics based on screening tests and health preferences tended to favor HPV-based screening strategies. Impact: Whether HPV-based screening will improve the balance between benefits and harms of cervical cancer screening depends on how the balance between benefits and harms is assessed.
Bibliographical noteFunding Information:
This work was supported by the Canadian Institutes of Health Research (operating grant 68893, team grant 83320, and catalyst grant HSE-151297 to E.L. Franco, and Fellowship Award to T. Malagón). Thestudy funder hadno rolein the studydesign; in the collection, analysis, and interpretation of the data; in the writing of the report; or in the decision to submit the article for publication. All the authors had full access to the data and take responsibility for the integrity of the data and the accuracy of the data analysis.