Abstract for: Our Walk to the End of Cancer? Understanding Long-Term Trends in Medical Screening
In this study we develop the first integrated, broad boundary feedback theory and formal model to explain the dynamics of medical screening. The theory includes a decision-theoretic core around harms and benefits including the fundamental tradeoff between sensitivity and specificity; and feedbacks that condition guidelines and actual practice. To provide context we use the case of PSA screening for prostate cancer as a motivating example, but our model is generic and applicable to other contexts such as mammography. We present a behaviorally realistic, boundedly-rational model of detection and selection for health screening that creates oscillations in policy recommendation thresholds of formal guidelines. This core model, entailing only the evidence generation and translation processes, demonstrates how oscillations are natural to this category of problems due to inherent delays in evidence-based screening. These fluctuations lead to long periods during which screening guidelines are suboptimal.