Adjustment for do-not-resuscitate orders reverses the apparent in-hospital mortality advantage for minorities

Purpose The use of do-not-resuscitate (DNR) orders may differ by sex or ethnicity, and DNR status may be associated with outcomes for hospitalized patients. Thus, we sought to determine whether differences in rates of DNR by sex and ethnicity influenced differences in mortality. Subjects and methods We included all patients admitted to nonfederal California hospitals in 1999 with stroke, congestive heart failure, pneumonia, chronic obstructive pulmonary disease, chronic renal failure, angina, or diabetes mellitus. Rates of physician orders for DNR written within 24 hours of hospital admission and in-hospital mortality were compared between sexes and ethnicities after adjustment for age, admission source and diagnosis, payment type, and comorbidity scores in multivariable logistic regression models. Results Of 327 890 patients included, 25 196 (7.7%) had DNR orders. In adjusted models, women were more likely to have DNR orders than men (odds ratio [OR] 1.19; 95% confidence interval 1.16–1.23; P<0.001) and non-Hispanic whites were more likely to have DNR orders than other ethnicities (OR 1.75; 1.69–1.82; P<0.001). Overall, 13 549 (4.1%) patients died in the hospital. Risk of death was greater in those with a DNR order (OR 7.0; 6.7–7.3; P<0.001). Non-Hispanic whites appeared to have a greater risk of in-hospital death in adjusted models (OR 1.09; 1.04–1.12; P<0.001) when DNR status was ignored; however, the risk of death appeared to be lower in non-Hispanic whites in the complete model with DNR included (OR 0.94; 0.90–0.99; P = 0.01). A survival advantage for women was also more apparent after including DNR status in the adjusted model. Conclusions Women and non-Hispanic whites are more likely to have DNR orders. DNR status affected the measurement of sex-ethnic differences in mortality risk.