An instrumental variable approach finds no associated harm or benefit with early dialysis initiation in the United States.
The estimated glomerular filtration rate (eGFR) at dialysis initiation has been rising. Observational studies suggest harm, but may be confounded by unmeasured factors. As instrumental variable methods may be less biased, we performed a retrospective cohort study of 310,932 patients who started dialysis between 2006 and 2008 and were registered in the United States Renal Data System in order to describe geographic variation in eGFR at dialysis initiation and determine its association with mortality. Patients were grouped into 804 health service areas (HSAs) by zip code. Individual eGFR at dialysis initiation averaged 10.8 ml/min per 1.73 m(2) but varied geographically. Only 11% of the variation in mean HSA-level eGFR at dialysis initiation was accounted for by patient characteristics. We calculated demographic-adjusted mean eGFR at dialysis initiation in the HSAs using the 2006 and 2007 incident cohort as our instrument and estimated the association between individual eGFR at dialysis initiation and mortality in the 2008 incident cohort using the two-stage residual inclusion method. Among 89,547 patients starting dialysis in 2008 with eGFR 5-20 ml/min per 1.73 m(2), eGFR at initiation was not associated with mortality over a median of 15.5 months (hazard ratio, 1.025 per 1 ml/min per 1.73 m(2) for eGFR 5-14 ml/min per 1.73 m(2); and 0.973 per 1 ml/min per 1.73 m(2) for eGFR 14-20 ml/min per 1.73 m(2)). Thus, there was no associated harm or benefit with early dialysis initiation in the United States.
Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA.
Julia J
JJ
Scialla
Chronic Disease Research Group, Minneapolis, Minnesota, USA.
Jiannong
J
Liu
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
Deidra C
DC
Crews
Chronic Disease Research Group, Minneapolis, Minnesota, USA.
Haifeng
H
Guo
Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Karen
K
Bandeen-Roche
1] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA [2] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Patti L
PL
Ephraim
Department of Medicine, Seven Oaks General Hospital, University of Manitoba, Winnipeg, Manitoba, Canada.
Navdeep
N
Tangri
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
Stephen M
SM
Sozio
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
Tariq
T
Shafi
Division of Nephrology, Tufts University School of Medicine, Boston, Massachusetts, USA.
Dana C
DC
Miskulin
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA [3] Department of Medicine, Academic Medical Center, Amsterdam, The Netherlands.
Wieneke M
WM
Michels
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA [3] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [4] Nephrology Center of Maryland, Baltimore, Maryland, USA.
Bernard G
BG
Jaar
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [3] Department of Health, Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [4] Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [5] Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Albert W
AW
Wu
San Francisco General Hospital and University of California San Francisco, San Francisco, California, USA.
Neil R
NR
Powe
1] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA [3] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [4] Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
L Ebony
LE
Boulware
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002391:Catchment Area, Health / Q000706:statistics & numerical data*; D016208:Databases, Factual; D061345:Early Medical Intervention; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D006435:Renal Dialysis / Q000009:adverse effects / Q000706:statistics & numerical data* / Q000639:trends; D051436:Renal Insufficiency, Chronic / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D013223:Statistics as Topic; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult