Cardiovascular and noncardiovascular mortality among patients starting dialysis.
BACKGROUND
Cardiovascular mortality is considered the main cause of death in patients receiving dialysis and is 10 to 20 times higher in such patients than in the general population.


OBJECTIVE
To evaluate if high overall mortality in patients starting dialysis is a consequence of increased cardiovascular mortality risk only or whether noncardiovascular mortality is equally increased.


METHODS
Using data from between January 1, 1994, and January 1, 2007, age-stratified mortality in a European cohort of adults starting dialysis and receiving follow-up for a mean of 1.8 (SD, 1.1) years (European Renal Association-European Dialysis and Transplant Association [ERA-EDTA] Registry [N = 123,407]) was compared with the European general population (Eurostat).


METHODS
Cause of death was recorded by ERA-EDTA codes in patients and matching International Statistical Classification of Diseases, 10th Revision codes in the general population. Standardized cardiovascular and noncardiovascular mortality rates, their ratio, difference, and relative excess of cardiovascular over noncardiovascular mortality were calculated.


RESULTS
Overall all-cause mortality rates in patients and the general population were 192 per 1000 person-years (95% confidence interval [CI], 190-193) and 12.055 per 1000 person-years (95% CI, 12.05-12.06), respectively. Cause of death was known for 90% of the patients and 99% of the general population. In patients, 16,654 deaths (39%) were cardiovascular and 21,654 (51%) were noncardiovascular. In the general population, 7,041,747 deaths (40%) were cardiovascular and 10,183,322 (58%) were noncardiovascular. Cardiovascular and noncardiovascular mortality rates in patients were respectively 38.1 per 1000 person-years (95% CI, 37.2-39.0) and 50.1 per 1000 person-years (95% CI, 48.9-51.2) higher than in the general population. On a relative scale, standardized cardiovascular and noncardiovascular mortality were respectively 8.8 (95% CI, 8.6-9.0) and 8.1 (95% CI, 7.9-8.3) times higher than in the general population. The ratio of these rates, ie, relative excess of cardiovascular over noncardiovascular mortality in patients starting dialysis compared with the general population, was 1.09 (95% CI, 1.06-1.12). Relative excess in a sensitivity analysis in which unknown/missing causes of death were regarded either as noncardiovascular or cardiovascular varied between 0.90 (95% CI, 0.88-0.93) and 1.39 (95% CI, 1.35-1.43).


CONCLUSIONS
Patients starting dialysis have a generally increased risk of death that is not specifically caused by excess cardiovascular mortality.
Department of Clinical Epidemiology, Leiden University Medical Center, C7-104, PO Box 9600, 2300 RC Leiden, The Netherlands. d.j.de_jager@lumc.nl
Dinanda J
DJ
de Jager
Diana C
DC
Grootendorst
Kitty J
KJ
Jager
Paul C
PC
van Dijk
Lonneke M J
LM
Tomas
David
D
Ansell
Frederic
F
Collart
Patrik
P
Finne
James G
JG
Heaf
Johan
J
De Meester
Jack F M
JF
Wetzels
Frits R
FR
Rosendaal
Friedo W
FW
Dekker
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012042:Registries; D006435:Renal Dialysis / Q000401:mortality*; D012306:Risk; D055815:Young Adult