Relationship between Stroke and Mortality in Dialysis... : Clinical Journal of the American Society of Nephrology (original) (raw)

Original Articles

Relationship between Stroke and Mortality in Dialysis Patients

Wetmore, James B.*; Phadnis, Milind A.†; Ellerbeck, Edward F.‡; Shireman, Theresa I.‡; Rigler, Sally K.§; Mahnken, Jonathan D.†

*Department of Medicine, Division of Nephrology, Hennepin County Medical Center, Minneapolis, Minnesota; and

†Department of Biostatistics,

‡Department of Preventive Medicine and Public Health, and

§Department of Medicine, University of Kansas School of Medicine, Kansas City, Kansas

Correspondence: Dr. James B. Wetmore, Division of Nephrology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN, 55415. Email: [email protected]

Received March 20, 2014

Accepted September 8, 2014

Online date: October 15, 2014

Abstract

Background and objectives

Stroke is common in patients undergoing long-term dialysis, but the implications for mortality after stroke in these patients are not fully understood.

Design, setting, participants, & measurements

A large cohort of dually-eligible (Medicare and Medicaid) patients initiating dialysis from 2000 to 2005 and surviving the first 90 days was constructed. Medicare claims were used to ascertain ischemic and hemorrhagic strokes occurring after 90-day survival. A semi-Markov model with additive hazard extension was generated to estimate the association between stroke and mortality, to calculate years of life lost after a stroke, and to determine whether race was associated with differential survival after stroke.

Results

The cohort consisted of 69,371 individuals representing >112,000 person-years of follow-up. Mean age±SD was 60.8±15.5 years. There were 21.1 (99% confidence interval [99% CI], 20.0 to 22.3) ischemic strokes and 4.7 (99% CI, 4.2 to 5.3) hemorrhagic strokes after cohort entry per 1000 patient-years. At 30 days, mortality was 17.9% for ischemic stroke and 53.4% for hemorrhagic stroke. The adjusted hazard ratio (AHR) depended on time since entry into the cohort; for patients who experienced a stroke at 1 year after cohort entry, for example, the AHR of hemorrhagic stroke for mortality was 25.4 (99% CI, 22.4 to 28.4) at 1 week, 9.9 (99% CI, 8.4 to 11.6) at 3 months, 5.9 (99% CI, 5.0 to 7.0) at 6 months, and 1.8 (99% CI, 1.5 to 2.1) at 24 months. The corresponding AHRs for ischemic stroke were 11.7 (99% CI, 10.2 to 13.1) at 1 week, 6.6 (99% CI, 6.4 to 6.7) at 3 months, and 4.7 (99% CI, 4.5 to 4.9) at 6 months, remaining significantly >1.0 even at 48 months. Median months of life lost were 40.7 for hemorrhagic stroke and 34.6 for ischemic stroke. For both stroke types, mortality did not differ by race.

Conclusions

Dialysis recipients have high mortality after a stroke with corresponding decrements in remaining years of life. Poststroke mortality does not differ by race.