The value of improving failures within a cervical cancer screening program: an example from Norway.

Failures in cervical cancer (CC) screening include nonparticipation, underscreening and loss to follow-up of abnormal results. We estimated the long-term health benefits from and maximum investments in interventions targeted to improving compliance to guidelines while remaining cost-effective. We used a mathematical model empirically calibrated to simulate the natural history of CC in Norway. A baseline scenario reflecting current practice using cytology-based screening was compared to scenarios that target different sources of noncompliance: (i) failure to follow-up women with abnormal results, (ii) screening less frequently than recommended (i.e., underscreening) and (iii) absence of screening. A secondary analysis included human papillomavirus (HPV)-based screening as the primary test. Model outcomes included reductions in lifetime cancer risk and incremental net monetary benefit (INMB) resulting from improvements with compliance. Compared to the status quo, improving all sources of noncompliance leads to important health gains and produced positive INMBs across a range of developed-country willingness-to-pay (WTP) thresholds. For example, a 2% increase in compliance could reduce lifetime cancer risk by 1-3%, depending on the targeted source of noncompliance and primary screening method. Assuming a WTP threshold of $83,000 per year of life saved and cytology-based screening, interventions that increase follow-up of abnormal results yielded the highest INMB per 2% increase in coverage [$19 ($10-21)]. With HPV-based screening, recruiting nonscreeners resulted in the largest INMB [$23 ($18-32)]. Considerable funds could be allocated toward policies that improve compliance with screening under the current cytology-based program or toward adoption of primary HPV-based screening while remaining cost-effective.