Leveling up: Treating Uptake as Endogenous May Increase the Value of Screening Programs.

Abstract

Background. We aimed to illustrate that health economists should consider individual heterogeneity when solving the problem of finding the optimal combination of sensitivity and specificity that maximizes the average health utility of a target population in a screening program. Methods. A theoretical framework compares the solution under standard economics of diagnoses to the optimal combination under an endogenous uptake analysis, where screening participation is given by heterogenous health preferences. An applied example used calibrated parameters with real data from the bowel cancer screening program in the United Kingdom. Scenario analyses show how the results would change with parameter values, if disease risk and health utilities were not independent and if screening uptake were not completely determined by health preferences. Results. A general theoretical result states that the endogenous uptake analysis leads to a weakly higher true- and false-positive rate than would be optimal under the standard approach. In the same way, the endogenous solution would lead to a lower uptake rate. The base-case scenario of the applied example illustrates that a screening program using the endogenous solution would generate 21.1% more quality-adjusted lifeyears than when using the standard solution. The scenario analyses show when the endogenous analysis is most valued and that the general result applies for a wide range of situations when theoretical assumptions are relaxed. Limitations. The results obtained are valid under the assumptions made. Analysts should evaluate if those could hold in the applied screening context. Conclusions. Individual heterogeneity and uptake decisions are relevant factors to consider in the problem of finding an optimal combination of sensitivity and specificity for a screening test.