In this paper, we identify 8 methods used to measure errors and adverse events in health care and discuss their strengths
and weaknesses. We focus on the reliability and validity of each, as well as the ability to detect latent errors (or system
errors) versus active errors and adverse events. We propose a general framework to help health care providers, researchers,
and administrators choose the most appropriate methods to meet their patient safety measurement goals.
Key words medical error - adverse events - patient safety - measurement
Dr. Thomas is a Robert Wood Johnson Foundation Generalist Physician Faculty Scholar. Dr. Petersen was an awardee in the Research
Career Development Award Program of the VA HSR&D Service (grant RCD 95-306) and is a Robert Wood Johnson Foundation Generalist
Physician Faculty Scholar.
The authors have no potential conflicts of interest. The authors’ funding agencies had no role in the study design; in the
collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for
publication.