Differences in survival on chronic dialysis treatment between ethnic groups in Denmark: a population-wide, national cohort study.
In Western countries, black and Asian dialysis patients experience better survival compared with white patients. The aim of this study is to compare the survival of native Danish dialysis patients with that of dialysis patients originating from other countries and to explore the association between the duration of residence in Denmark before the start of dialysis and the mortality on dialysis.



We performed a population-wide national cohort study of incident chronic dialysis patients in Denmark (≥18 years old) who started dialysis between 1995 and 2010.



In total, 8459 patients were native Danes, 344 originated from other Western countries, 79 from North Africa or West Asia, 173 from South or South-East Asia and 54 from sub-Saharan Africa. Native Danes were more likely to die on dialysis compared with the other groups (crude incidence rates for mortality: 234, 166, 96, 110 and 53 per 1000 person-years, respectively). Native Danes had greater hazard ratios (HRs) for mortality compared with the other groups {HRs for mortality adjusted for sociodemographic and clinical characteristics: 1.32 [95% confidence interval (CI) 1.14-1.54]; 2.22 [95% CI 1.51-3.23]; 1.79 [95% CI 1.41-2.27]; 2.00 [95% CI 1.10-3.57], respectively}. Compared with native Danes, adjusted HRs for mortality for Western immigrants living in Denmark for ≤10 years, >10 to ≤20 years and >20 years were 0.44 (95% CI 0.27-0.71), 0.56 (95% CI 0.39-0.82) and 0.86 (95% CI 0.70-1.04), respectively. For non-Western immigrants, these HRs were 0.42 (95% CI 0.27-0.67), 0.52 (95% CI 0.33-0.80) and 0.48 (95% CI 0.35-0.66), respectively.



Incident chronic dialysis patients in Denmark originating from countries other than Denmark have a better survival compared with native Danes. For Western immigrants, this survival benefit declines among those who have lived in Denmark longer. For non-Western immigrants, the survival benefit largely remains over time.
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands Department of Nephrology, Sint Lucas Andreas Hospital, Amsterdam, The Netherlands.
Tessa O
TO
van den Beukel
Department of Nephrology, Rigshospitalet, Copenhagen, Denmark.
Kristine
K
Hommel
Department of Nephrology, Rigshospitalet, Copenhagen, Denmark.
Anne-Lise
AL
Kamper
Department of Medicine, Roskilde Hospital, University of Copenhagen, Roskilde, Denmark.
James G
JG
Heaf
Department of Nephrology, Sint Lucas Andreas Hospital, Amsterdam, The Netherlands.
Carl E H
CE
Siegert
Department of Psychiatry, Sint Lucas Andreas Hospital and VU University Medical Center, Amsterdam, The Netherlands.
Adriaan
A
Honig
ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Kitty J
KJ
Jager
Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
Friedo W
FW
Dekker
Danish Research Centre for Migration, Ethnicity and Health, Section of Health Services Research, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
Marie
M
Norredam
D000328:Adult; D000368:Aged; D044466:Asian People / Q000208:ethnology; D044383:Black People / Q000208:ethnology; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D054242:Emigrants and Immigrants; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000208:ethnology / Q000401:mortality* / Q000628:therapy; D017678:Sex Distribution; D044465:White People
Denmark; dialysis; ethnicity; survival analysis