OPEN Health
Professor Ben van Hout - Scientific Founder
Professor Ben van Hout is the Scientific Founder at OPEN Health HEOR & Market Access and Professor of Health Economics at the University of Sheffield. Ben has extensive experience in economic modeling and has contributed to the methodology of economic evaluation in various areas. Bens core expertise is in quality-of-life research, Bayesian statistics, complex data analyses, and economic modeling.
An article written by Ben van Hout
Excuses and Confusion With Respect to Survival Analysis
Excuses An exponential model assumes that the probability to die at any point in time is constant, conditional upon whether one has lived up till that point (the hazard rate). Cancers grow; the bigger the tumour load, the higher the probability of dying and as such one would expect the hazard rate to increase over time. Thus, an exponential model may not make sense.
One may have heard me saying something along those lines during ISPOR conferences. I remember one occasion when a junior researcher proudly showed me that an exponential model fitted the data quite well, and I asked, a bit tongue-in-cheek, whether this made sense.
She should have humiliated me, with all respect, of course. She should have responded by telling me, “Each individual may have his/her own cancer growth curve, and indeed for each individual, the probability of dying may increase with time. And yes, an exponential model for cancer survival may not make much sense on an individual level. However, Professor van Hout, that does not mean that it cannot be appropriate on a population level.”