A string of mistakes: the importance of cascade analysis in describing, counting, and preventing medical errors.
BACKGROUND
Notions about the most common errors in medicine currently rest on conjecture and weak epidemiologic evidence. We sought to determine whether cascade analysis is of value in clarifying the epidemiology and causes of errors and whether physician reports are sensitive to the impact of errors on patients.


METHODS
Eighteen US family physicians participating in a 6-country international study filed 75 anonymous error reports. The narratives were examined to identify the chain of events and the predominant proximal errors. We tabulated the consequences to patients, both reported by physicians and inferred by investigators.


RESULTS
A chain of errors was documented in 77% of incidents. Although 83% of the errors that ultimately occurred were mistakes in treatment or diagnosis, 2 of 3 were set in motion by errors in communication. Fully 80% of the errors that initiated cascades involved informational or personal miscommunication. Examples of informational miscommunication included communication breakdowns among colleagues and with patients (44%), misinformation in the medical record (21%), mishandling of patients' requests and messages (18%), inaccessible medical records (12%), and inadequate reminder systems (5%). When asked whether the patient was harmed, physicians answered affirmatively in 43% of cases in which their narratives described harms. Psychological and emotional effects accounted for 17% of physician-reported consequences but 69% of investigator-inferred consequences.


CONCLUSIONS
Cascade analysis of physicians' error reports is helpful in understanding the precipitant chain of events, but physicians provide incomplete information about how patients are affected. Miscommunication appears to play an important role in propagating diagnostic and treatment mistakes.
Woolf
Steven H
SH
Department of Family Medicine, Virginia Commonwealth University, Richmond, VA, USA. swoolf@vcu.edu
Kuzel
Anton J
AJ
Dovey
Susan M
SM
Phillips
Robert L
RL
D000293:Adolescent; D000328:Adult; D000368:Aged; D015984:Causality; D003142:Communication; D005260:Female; D006801:Humans; D008297:Male; D019300:Medical Errors / Q000517:prevention & control* / Q000706:statistics & numerical data*; D008875:Middle Aged; D015203:Reproducibility of Results; D013597:Systems Analysis; D014342:Truth Disclosure