Table 3.

Unadjusted and adjusted HRs of 1-year mortality for all patients

Number of StationsProportion of Death (Deaths/Total)Death Rate (n per 100 patient-yr)Unadjusted ResultsAdjusted Results: Model 1a
HR (95% CI)P (versus Reference)HR (95% CI)P (versus Reference)
1–530.4 (279/918)40.01.87 (1.45 to 2.40)<0.0011.26 (1.03 to 1.54)0.02
6–1024.1 (4647/19,259)30.21.41 (1.32 to 1.51)<0.0011.13 (1.07 to 1.19)<0.001
11–1521.2 (14,963/70,640)25.91.21 (1.16 to 1.26)<0.0011.04 (1.00 to 1.08)0.03
16–2020.0 (23,585/118,042)24.21.13 (1.09 to 1.18)<0.0011.04 (1.00 to 1.07)0.05
21–2519.5 (17,344/89,149)23.41.10 (1.05 to 1.15)<0.0011.05 (1.01 to 1.09)0.01
26–3017.9 (7385/41,145)21.31 (reference)1 (reference)
31–3518.2 (3602/19,826)21.61.01 (0.95 to 1.08)0.721.08 (1.03 to 1.14)0.002
36–4517.4 (3125/17,911)20.60.97 (0.90 to 1.04)0.411.03 (0.97 to 1.09)0.34
46–6016.5 (1118/6772)19.30.91 (0.81 to 1.01)0.090.98 (0.89 to 1.09)0.72
≥6117.8 (251/1412)21.10.99 (0.86 to 1.14)0.921.16 (0.99 to 1.36)0.08
Number of StationsAdjusted Results: Model 2bAdjusted Results: Model 3cAdjusted Results: Model 4d
HR (95% CI)P (versus Reference)HR (95% CI)P (versus Reference)HR (95% CI)P (versus Reference)
1–51.27 (1.03 to 1.56)0.021.31 (1.08 to 1.60)0.0071.33 (1.09 to 1.63)0.005
6–101.12 (1.06 to 1.18)<0.0011.16 (1.09 to 1.22)<0.0011.17 (1.11 to 1.23)<0.001
11–151.04 (1.00 to 1.08)0.031.05 (1.01 to 1.09)0.0081.06 (1.02 to 1.10)0.002
16–201.04 (1.00 to 1.07)0.031.03 (1.00 to 1.07)0.051.04 (1.01 to 1.08)0.02
21–251.05 (1.01 to 1.09)0.0061.05 (1.01 to 1.09)0.011.05 (1.01 to 1.09)0.006
26–301 (reference)1 (reference)1 (reference)
31–351.08 (1.02 to 1.13)0.0031.08 (1.03 to 1.13)0.0031.07 (1.02 to 1.13)0.007
36–451.02 (0.97 to 1.08)0.391.02 (0.97 to 1.08)0.411.02 (0.97 to 1.08)0.42
46–600.98 (0.89 to 1.09)0.750.98 (0.89 to 1.08)0.670.97 (0.88 to 1.07)0.50
≥611.13 (0.98 to 1.32)0.101.14 (0.97 to 1.35)0.111.11 (0.92 to 1.34)0.29
  • a Adjusted for patient demographic and clinical factors, including race/ethnicity, age, sex, body mass index, estimated GFR, cause of ESRD (diabetes, hypertension, GN, other, and unknown), presence of comorbid conditions (hypertension, diabetes, cardiac failure, atherosclerotic heart disease, cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary disease, and cancer), lifestyle behaviors (smoking, alcohol, and drug dependence), immobility, and pre-ESRD use of erythropoiesis-stimulating agents (model 1).

  • b Additionally adjusted for patient zip code race/ethnicity-specific income, health insurance, and employment (model 2).

  • c Additionally adjusted for facility structural and geographic region, including for-profit status, chain ownership (Dialysis Clinic, Inc., DaVita, Fresenius, other chains, and no chain affiliation), urban/rural location, and US Census regions (Northeast, South, Midwest, and West; model 3).

  • d Additionally adjusted for facility zip code SES, including median household income, percentage of persons who completed high school, percentage of persons in poverty, and percentage of black population (model 4).