Nontraumatic subarachnoid hemorrhage in maintenance dialysis hospitalizations: trends and outcomes

Abstract

Background and purpose: Subarachnoid hemorrhage (SAH) is associated with high mortality, and patients on maintenance dialysis have been shown to be at higher risk for stroke including SAH. However, the outcomes of patients on maintenance dialysis with SAH are not well known. This study was designed to look at incidence and outcomes of SAH in those on maintenance dialysis.

Methods: Using the Nationwide Inpatient Sample Database, hospitalizations with nontraumatic SAH were identified. Age-adjusted incidence rates were calculated by direct standardization to the 2000 US standard population. Logistic regression was used to assess the risk factors for mortality.

Results: Of an estimated 149,091 hospitalizations with SAH, 1631 patients (10.9%) were on maintenance dialysis. Unadjusted incidence of SAH hospitalizations was higher in maintenance dialysis than in the general population (73.5 versus 11.2 per 100,000 population), and similar results were seen on age-adjusted analysis. The unadjusted all-cause inpatient mortality rate for SAH admissions was higher in maintenance dialysis versus the general population (38.4% versus 21.9%; P<0.001). Maintenance dialysis was an independent predictor of mortality (odds ratio, 2.48; 95% confidence interval, 1.85-3.34), although other significant predictors of mortality were similar in both subgroups. Incidence of SAH hospitalizations has been relatively stable during the study period, but mortality seems to be decreasing.

Conclusions: SAH hospitalizations are more common and associated with higher mortality in patients on maintenance dialysis than in the general population. Although being on maintenance dialysis is an independent predictor for mortality in patients with SAH, other predictors of mortality evaluated in this study are not necessarily different between the 2 groups.

Keywords: dialysis; hospitalization; subarachnoid hemorrhage.