Dose of hemodialysis and survival: differences by race and sex.
BACKGROUND
Although blacks receive lower doses of hemodialysis than whites, their survival when receiving dialysis treatment is better than that for whites. Previous studies of the relationship between the dose of dialysis and patient survival have not controlled for differences in patient characteristics.


OBJECTIVE
To examine the association of mortality with the dose of hemodialysis for clusters of patients categorized by race and sex.


METHODS
Retrospective analysis of laboratory data and mortality outcomes from 1994, using a national database of hemodialysis patients.


METHODS
A total of 18144 black and white patients receiving hemodialysis 3 times weekly who either lived the entire year receiving hemodialysis or died.


METHODS
The fractional reduction of urea in a single dialysis session as the measured hemodialysis dose (urea reduction ratio [URR]) after controlling for race, sex, age, and diabetes mellitus. Mortality was determined by strata of URRs and albumin and creatinine levels.


RESULTS
Across all age categories, blacks had lower URRs than whites, and men had lower URRs than women. In an age-adjusted model for evaluating interactions among URRs, race, sex, and diabetes, the association of URR with mortality risk was weak among blacks, particularly black men. After adjustment for age and diabetes, death probability curves were most steep for white women with URR values less than 60%. The death probability curves were least steep for black men. There was no meaningful difference between death probability and albumin or creatinine concentration among the race by sex clusters.


CONCLUSIONS
Using URR, the usual measure of hemodialysis dose, the assumption that the association between dialysis dose and survival is uniform across demographic groups appears incorrect. Comparisons of the quality of dialysis patient care should not rely on URR alone to predict patient survival.
Owen
W F
WF
Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA. wfowen@bics.bwh.harvard.edu
Chertow
G M
GM
Lazarus
J M
JM
Lowrie
E G
EG
D001741:Black or African American / Q000706:statistics & numerical data*; D000368:Aged; D003404:Creatinine / Q000097:blood; D003928:Diabetic Nephropathies / Q000401:mortality* / Q000628:therapy*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011336:Probability; D006435:Renal Dialysis / Q000592:standards* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012709:Serum Albumin; D017678:Sex Distribution; D016019:Survival Analysis; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014508:Urea; D044465:White People / Q000706:statistics & numerical data*
D012709:Serum Albumin; D014508:Urea; D003404:Creatinine