BACKGROUND: The four principles of Beauchamp and Childress--autonomy, 
non-maleficence, beneficence and justice--have been extremely influential in the 
field of medical ethics, and are fundamental for understanding the current 
approach to ethical assessment in health care. This study tests whether these 
principles can be quantitatively measured on an individual level, and then 
subsequently if they are used in the decision making process when individuals 
are faced with ethical dilemmas.
METHODS: The Analytic Hierarchy Process was used as a tool for the measurement 
of the principles. Four scenarios, which involved conflicts between the medical 
ethical principles, were presented to participants who then made judgments about 
the ethicality of the action in the scenario, and their intentions to act in the 
same manner if they were in the situation.
RESULTS: Individual preferences for these medical ethical principles can be 
measured using the Analytic Hierarchy Process. This technique provides a useful 
tool in which to highlight individual medical ethical values. On average, 
individuals have a significant preference for non-maleficence over the other 
principles, however, and perhaps counter-intuitively, this preference does not 
seem to relate to applied ethical judgements in specific ethical dilemmas.
CONCLUSIONS: People state they value these medical ethical principles but they 
do not actually seem to use them directly in the decision making process. The 
reasons for this are explained through the lack of a behavioural model to 
account for the relevant situational factors not captured by the principles. The 
limitations of the principles in predicting ethical decision making are 
discussed.