Hostname: page-component-7c8c6479df-8mjnm Total loading time: 0 Render date: 2024-03-27T11:17:52.480Z Has data issue: false hasContentIssue false

Microrisks for Medical Decision Analysis

Published online by Cambridge University Press:  10 March 2009

Ronald A. Howard
Affiliation:
Stanford University

Extract

Many would agree on the need to inform patients about the risks of medical conditions or treatments and to consider those risks in making medical decisions. The question is how to describe the risks and how to balance them with other factors in arriving at a decision. In this article, we present the thesis that part of the answer lies in defining an appropriate scale for risks that are often quite small. We propose that a convenient unit in which to measure most medical risks is the microprobability, a probability of 1 in 1 million. When the risk consequence is death, we can define a micromort as one microprobability of death. Medical risks can be placed in perspective by noting that we live in a society where people face about 270 micromorts per year from interactions with motor vehicles.

Continuing risks or hazards, such as are posed by following unhealthful practices or by the side-effects of drugs, can be described in the same micromort framework. If the consequence is not death, but some other serious consequence like blindness or amputation, the microrisk structure can be used to characterize the probability of disability.

Once the risks are described in the microrisk form, they can be evaluated in terms of the patient's willingness-to-pay to avoid them. The suggested procedure is illustrated in the case of a woman facing a cranial arteriogram of a suspected arterio-venous malformation. Generic curves allow such analyses to be performed approximately in terms of the patient's sex, age, and economic situation. More detailed analyses can be performed if desired.

Microrisk analysis is based on the proposition that precision in language permits the soundness of thought that produces clarity of action and peace of mind.

Type
Special Section: Technology Assessment and Surgical Policy
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Howard, R. A. On making life and death decisions. Readings on the principles and applications of decision analysis, vol. 2. Menlo Park, CA: Strategic Decisions Group.Google Scholar
(Reprinted from Societal risk assessment, Schwing, R. C. & Albers, W. R. Jr, (Eds.). General Motors Research Laboratories, 1980, 89113.)Google Scholar
Howard, R. A., On fates comparable to death. Readings on the principles and applications of decision analysis, vol. 2. Menlo Park, CA: Strategic Decisions Group.Google Scholar
(Reprinted from Management Science, vol. 30, No. 4, 04 1984.)Google Scholar