APPLICATION OF THE PRINCIPLE OF MARGINAL ANALYSIS TO SAMPLING PRACTICE USING PROSTATIC CHIPPINGS AS A MODEL

Aims-To demonstrate an application of health economic principles in hi stopathology by using the sampling of transurethral resections of pros tate specimens. By demonstrating how marginal costs are calculated the aim is to illustrate that the potential opportunity cost of sampling entire specimens is much greater than would be anticipated by taking a verage cost, or the cost of producing a histological section alone. Me thod-A mathematical model is used with data obtained from the Aberdeen pathology department files and published estimates of the likely perc entage of cancerous chippings in each specimen. Results-The average co st of each cancer detected remains low, between pound 47 and pound 151 , in all the scenarios examined. However, the marginal costs can becom e high, exceeding pound 10 000 in larger specimens, if all the chippin gs are processed. Conclusions-This study demonstrates that there are p otential opportunity cost penalties to histopathological services asso ciated with sampling strategies. Although the results are derived from a hypothetical mathematical model using local data that applies only to histopathology, the method could be widely applied. The principles of marginal analysis should be performed by multidisciplinary teams an d include outcomes as well as a broader range of costs, including thos e that arise subsequent to diagnosis.