BACKGROUND. Whereas studies have shown higher mortality rates in patients w
ith do-not-resuscitate (DNR) orders, most have not accounted for confoundin
g factors related to the use of DNR orders and/or factors related to the ri
sk of death.
OBJECTIVE. TO determine the relationship between the use of DNR orders and
in-hospital mortality, adjusting for severity of illness and other covariat
es.
DESIGN. Retrospective cohort study.
PATIENTs. There were 13,337 consecutive stroke admissions to 30 hospitals i
n 1991 to 1994.
MEASURES. TO decrease selection bias, propensity scores reflecting the like
lihood of a DNR order were developed. Scores were based on nine demographic
and clinical variables independently related to use of DNR orders. The odd
s of death in patients with DNR orders were then determined using logistic
regression, adjustment for propensity scores, severity of illness, and othe
r factors.
RESULTS. DNR orders were used in 22% (n 2,898) of patients. In analyses exa
mining DNR orders written at any time during hospitalization, unadjusted in
-hospital mortality rates were higher in patients with DNR orders than in p
atients without orders (40% vs. 2%, P < 0.001); the adjusted odds of death
was 33.9 (95% CI, 27.4-42.0). The adjusted odds of death remained higher in
analyses that only considered orders written during the first 2 days (OR 3
.7; 95% CI, 3.2-4.4) or the first day (OR 2.4; 95% CI, 2.0-2.9). In stratif
ied analyses, adjusted odds of death tended to be higher in patients with l
ower propensity scores.
CONCLUSION. The risk of death was substantially higher in patients with DNR
orders after adjusting for propensity scores and other covariates. Whereas
the increased risk may reflect patient preferences for less intensive care
or unmeasured prognostic factors, the current findings highlight the need
for more direct evaluations of the quality and appropriateness of care of p
atients with DNR orders.