1. Am J Kidney Dis. 2014;63(6):806-815 R3 박세정 /prof. 이태원 Comparative Effectiveness of Early Versus Conventional Timing of Dialysis Initiation in Advanced CKD

2. trend during the past decade : initiation of dialysis therapy at higher levels of kidney function the IDEAL (Initiating Dialysis Early and Late) trial Most observational studies have been limited by lead time bias & survivor bias. Sjölander A, et al. Comparing different strategies for timing of dialysis initiation through inverse probability weighting. Am J Epidemiol. 2011;174(10):1204-1210.  allows survival time to originate at a common level of kidney function allows pts who die before starting dialysis to contribute to the analysis BMJ 2010;340:b5087

3. METHODS Overview an observational cohort study comparing the effectiveness of early vs. later dialysis therapy initiation among adults with advanced CKD Data Source and Study Population Cleveland Clinic Foundation (CCF) CKD Registry (at least 2 eGFR ≤ 60 mL/min/1.73 ㎡ 90 days apart) January 1, 2005 ~ September 15, 2009 diagnosis code : CKD, polycystic kidney disease, glomerulonephritis, diabetic nephropathy, hypertensive nephrosclerosis, renovascular disease Data Collection demographic, sCr level, cause of ESRD, comorbid conditions

4. METHODS Study Population Serum Creatinine Measurements varied in number and timing MDRD (Modification of Diet in Renal Disease) Study equation Cohort Inclusion Criteria mimic a clinical trial randomly assigning pts at risk for ESRD to early or later dialysis therapy initiation best linear unbiased prediction 

6. METHODS Key Variables Dialysis Initiation Strategy early : begin dialysis w/ a predicted eGFR ≥ 10 & <20 mL/min/1.73 ㎡ later : begin dialysis w/ a predicted eGFR <10 mL/min/1.73 ㎡ undeclared Covariates defined based upon proximity of their measurement to the date of study entry age, race, sex, smoking status, comorbid conditions, causes of CKD, median BWt, phosphate binder & vit D use, erythropoiesis-stimulating agent use, serum iPTH & P levels, Hb, K, BUN, serum bicarbonate, serum albumin, proteinuria Outcome Assessment mortality = death from any cause, ascertained from the electronic health records

7. METHODS Stastical Analyses “from-threshold” analysis  survivor bias inverse probability weighting Sensitivity and Diagnosis Analyses examined various truncation threshold declared discrepancy between dialysis therapy initiation strategy as defined by predicted eGFR and as ascertained from the USRDS record of the observed eGFR

8. RESULTS Patient Characteristics by Dialysis Status

10. RESULTS Patient Characteristics by Dialysis Initiation Strategy

13. RESULTS Mortality hazard ratio 1.59 (95% CI 0.89-2.84)

14. CONCLUSION Most patients did not initiate dialysis therapy during follow-up, and many died without ever receiving dialysis. No statistically significant difference in survival was observed for early and later initiation strategies. This is the first US-based study accounting for both lead time bias and survivor bias in an analysis of outcomes related to dialysis therapy timing.