Table 3.

Explicit Definitions of Futility in Studies Supporting Claims of Futility

Author	Intervention/population	Definition	Reference to Schneiderman’s threshold	Type of definition	Comment
Cone 200516	CPR§/ OOHCA§	A 1/100 chance of helping the patient	Yes	A posteriori	Addresses issue of the confidence interval & need for denominator≥ 100
Hamel 199738	Dialysis + ICU§/ ICU	CE ratio of $50,000/QALY§	No	A priori	Does not discuss futility as much as cost- effectiveness
Rodriguez 199739	ICU/ ICU	Less than 2% chance of survival with favorable function	Yes	A priori	Refers to Schneiderman's threshold but does not necessarily accept it
Sasson 200833	CPR/OOHCA	Less than 1% success	Yes	A priori	Does not refer to denominator, but refers to power to detect misclassification
Teno 199440	ICU or hospital treatment/ seriously ill adult patients	No more than 1% chance of 2 month survival	Yes	A priori	Refers to Schneiderman’s threshold but does not necessarily accept
Väyrynen 200837	CPR/a-systolic OOHCA	Cut off of 1% chance of survival	Yes	A priori	No reference to denominator

§ICU: intensive care unit, CPR: cardiopulmonary resuscitation, OOHCA: out of hospital cardiac arrest, CE: cost effectiveness, QALY: quality adjusted life year.