Sex Differences in "Do Not Attempt Resuscitation" Orders After Out-of-Hospital Cardiac Arrest and the Relationship to Critical Hospital Interventions

Abstract

Purpose: Women who experience out-of-hospital cardiac arrest have similar rates of survival to hospital admission as men; however, women are less likely to survive to hospital discharge. We hypothesized that women would have higher rates of "do not attempt resuscitation" (DNAR) orders and that this order would be associated with lower use of aggressive interventions.

Methods: We identified adult hospital admissions with a diagnosis of cardiac arrest (ICD-9 427.5) from the 2010 California State Inpatient Dataset. Multivariable logistic regression was used to test the association between patient sex and a DNAR order within the first 24 h of admission, adjusting for patient demographic characteristics and comorbid medical conditions. In secondary analysis, procedures performed after establishment of DNAR order and survival to hospital discharge were compared by sex.

Findings: We analyzed 6562 patients (44% women, 56% men) who experienced out-of-hospital cardiac arrest and survived to hospital admission. In unadjusted analysis, more women than men had establishment of a DNAR order during the first 24 h of admission (23.4% versus 19.3%; P < 0.01). After adjusting for age, race, and comorbid conditions, women remained significantly more likely to have a DNAR order established during the first 24 h of their hospital admission after cardiac arrest compared with men (odds ratio = 1.23; 95% CI, 1.09-1.40). No sex difference was found in procedures used after DNAR order was established.

Implications: Female survivors of cardiac arrest are significantly more likely than men to have a DNAR order established within the first 24 h of in-hospital treatment. The establishment of a DNAR order is associated with patients undergoing fewer procedures than individuals who do not have a DNAR order established. Given that patients who have a DNAR order receive less-aggressive intervention after arrest, it is possible that an early DNAR order may contribute to sex differences in survival to hospital discharge.

Keywords: DNR; cardiac arrest; outcomes; sex differences.