Modelling the cost-effectiveness and capacity impact of changes to colposcopy referral guidelines for women with mild dyskaryosis in the UK Cervical Screening Programme.

OBJECTIVE To evaluate the capacity implications and health economic impact of new guidelines recommending referral to colposcopy after one mild result during cervical screening rather than after two consecutive mild results. DESIGN A mathematical model of the country's colposcopy services and the clinical pathways from smear result through to treatment is constructed. The model incorporates national questionnaire data on referral numbers and management practices, routine data and published research results. SETTING All English NHS colposcopy services. POPULATION Women aged 25 to 64 years. METHODS The national average workload impact of the change in referral guidelines is predicted, and the impact in differing local circumstances is evaluated within the model. A long-term health economic model examines the resulting costs and predicted change in quality-adjusted life years (QALYs). MAIN OUTCOME MEASURES Colposcopy workload implications for single mild dyskaryosis referral and cost per QALY analysis. RESULTS We found that single mild dyskaryosis referral implies, on average, a 21% increase in colposcopy workload for services not currently operating this policy. The health economic model predicted a cost per QALY gained as a result of the implementation of the new referral guidelines of around pound7,500. CONCLUSIONS Referral after one mild result will increase workload at colposcopy; however, it may be possible to counterbalance the additional workload by altering other clinical practice. The change to referral guidelines would be considered cost-effective in comparison with many interventions routinely available on the NHS.