To screen or not to screen? Is it worth it for oral cancer?

Abstract

Design The cost-effectiveness of oral cancer screening programmes in a number of primary care environments was simulated using a decision analysis model. Primary data on actual resource use and costs were collected by case note review in two hospitals. Additional data needed to inform the model were obtained from published costs, from systematic reviews and by expert opinion using the Trial Roulette approach1. The value of future research was determined using 'expected value of perfect information' (EVPI) for the decision to screen and for each of the model inputs. Setting Hypothetical screening programmes conducted in a number of primary care settings. Eight strategies were compared: (A) no screen; (B) invitational screen in general medical practice; (C) invitational screen in general dental practice; (D) opportunistic screen in general medical practice; (E) opportunistic screen in general dental practice; (F) opportunistic high-risk screen in general medical practice; (G) opportunistic high-risk screen in general dental practice; and (H) invitational screen with a specialist. Participants were a hypothetical population over the age of 40 years of age. Main outcome measures The main measures were mean lifetime costs and quality-adjusted life-years (QALY) of each alternative screening scenario and incremental cost-effectiveness ratios (ICER) to determine the additional costs and benefits of each strategy over another. Results No screening (strategy A) was always the cheapest option. Strategies B, C, E and H were never cost-effective and were ruled out by dominance or extended dominance. Of the remaining strategies, the ICER for the whole population (age 49–79 years) ranged from £15 790 to £25 961 per QALY. Modelling a 20% reduction in disease progression always gave the lowest ICER. Cost-effectiveness acceptability curves showed that there is considerable uncertainty in the optimal decision identified by the ICER, depending on both the maximum amount that the UK National Health Service may be prepared to pay and the impact that treatment has on the annual malignancy transformation rate. Overall, however, high-risk opportunistic screening by a general dental or medical practitioner (strategies F and G) may be cost-effective. EVPI were high for all parameters with population values ranging from £8 million to £462 million. The values were significantly higher in males than females, however, but also varied depending upon malignant transformation rate, effects of treatment and willingness to pay. Partial EVPI showed the highest values for malignant transformation rate, disease progression, self-referral and costs of cancer treatment. Conclusions Opportunistic high-risk screening, particularly in general dental practice, may be cost-effective. This screening may be more effectively targeted to younger age groups, particularly 40–60 year olds. There is considerable uncertainty in the parameters used in the model, however, particularly malignant transformation rate, disease progression, patterns of self-referral and costs. Further study is needed on malignant transformation rates of oral, potentially malignant lesions and to determine the outcome of treatment of those lesions. Evidence has been published to suggest that intervention has no greater benefit than 'watch and wait' and, hence, a properly planned randomised controlled trial may be justified. Research is also needed into the rates of progression of oral cancer and on referral pathways from primary to secondary care and their effects on delay and stage of presentation.