Uncertainty of the Knowledge Base

Compared with many other highly technical hazardous endeavors, health care activities—despite many advances—are inexact procedures based upon incomplete knowledge, and are performed in a rapidly changing world on an increasingly aging population. Uncertainty is large, and error margins are small. Health care professionals and their patients both possess incomplete medical knowledge. As one surgeon recently noted:

We look for medicine to be an orderly field of knowledge and procedure. But it is not. It is an imperfect science, an enterprise of constantly changing knowledge, uncertain information, fallible individuals, and at the same time lives on the line. There is science in what we do, yes, but also habit, intuition, and sometimes plain old guessing. The gap between what we know and what we aim for persists. And this gap complicates everything we do (Gawande, 2002:7).

Event Investigation

Accidents in non–health care domains, such as transportation, are newsworthy and publicly investigated, and the results are widely disseminated. In contrast, mishaps in health care, again with some exceptions (e.g., radiological events), tend to be investigated quietly at the local level, and, until recently, findings were neither shared nor made available for public scrutiny.


In summary, health care institutions are complex systems, and their complexity includes features that are less often present in the kinds of hazardous hi-tech systems that are often used as models for effective safety management. This does not mean that health care professionals cannot learn valuable safety lessons from these other domains; rather, HCOs, policy officials, nurses, and all parties working to increase patient safety need to be mindful of the distinctive features of health care delivery that make it even more susceptible to the production of errors.


Berwick D. 2002. A user’s manual for the IOM’s “Quality Chasm” report. Health Affairs 21(3):80–90.

Gawande A. 2002. Complications: A Surgeon’s Notes on an Imperfect Science. New York, NY: Metropolitan Books, Henry Holt and Company.

Goodman P. 2001. Missing Organizational Linkages: Tools for Cross-Level Organizational Research. Thousand Oaks, CA: Sage Publications.

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