Table 3.
HR of AVF use based on univariate and multivariate competing risk analysis
| Covariatea | Level | Unadjusted HR (95% CI) | Adjusted HR (95% CI) |
|---|---|---|---|
| Primary exposure of interest | |||
| Surgeon supply group, by quartile | First (<8.6) | Reference | |
| Second (8.6 to <10.6) | 1.05 (1.02–1.07) | 1.04 (1.01–1.07) | |
| Third (10.6 to <13.6) | 0.98 (0.96–1.01) | 1.04 (1.01–1.07) | |
| Fourth (≥13.6) | 0.96 (0.94–0.99) | 1.03 (1.00–1.06) | |
| Race | Black | 0.93 (0.91–0.95) | 0.90 (0.88–0.92) |
| White | Reference | ||
| Patient sociodemographic and clinical factors at hemodialysis initiation | |||
| Age | <45 | Reference | |
| 45 to <65 | 1.01 (0.99–1.04) | 1.04 (1.01–1.07) | |
| 65 to <80 | 0.83 (0.81–0.86) | 0.92 (0.89–0.95) | |
| 80+ | 0.64 (0.61–0.66) | 0.74(0.71–0.77) | |
| Sex of patient | Male | 1.47 (1.44–1.50) | 1.46 (1.43–1.49) |
| Female | Reference | ||
| Insurance status at ESRD onset | Private employer group insurance | Reference | |
| Medicaid | 0.77 (0.75–0.80) | 0.92 (0.89–0.95) | |
| Medicare | 0.73 (0.71–0.76) | 0.93 (0.90–0.96) | |
| DVA or other | 0.86 (0.83–0.90) | 0.93 (0.89–0.97) | |
| Uninsured | 0.92 (0.88–0.96) | 0.95 (0.91–0.99) | |
| Primary cause of renal failure | Diabetes | 1.08 (1.06–1.11) | 1.05 (1.03–1.08) |
| Glomerulonephritis | 1.03 (0.99–1.07) | 0.94 (0.90–0.98) | |
| Hypertension | Reference | ||
| BMI (kg/m2) | <24.0 | Reference | |
| 24.0 to <28.3 | 1.18 (1.15–1.21) | 1.12 (1.09–1.15) | |
| 28.3 to <34.1 | 1.28 (1.24–1.31) | 1.19 (1.16–1.23) | |
| ≥34.1 | 1.25 (1.22–1.29) | 1.21 (1.17–1.24) | |
| Nephrology care before ESRD | Yes vs. no | 1.07 (1.04–1.09) | 1.08 (1.05–1.10) |
| Comorbid conditions | |||
| Coronary artery disease | Yes vs. no | 0.89 (0.86–0.91) | 0.97 (0.94–1.00) |
| Drug and alcohol use | Yes vs. no | 0.85 (0.81–0.90) | 0.82 (0.78–0.87) |
| Congestive heart failure | Yes vs. no | 0.83 (0.82–0.85) | 0.89 (0.88–0.91) |
| Need assistance with daily activities | Yes vs. no | 0.66 (0.64–0.68) | 0.82 (0.79–0.84) |
| Hypertension | Yes vs. no | 1.23 (1.19–1.27) | 1.19 (1.15–1.22) |
| Transient ischemic attack | Yes vs. no | 0.82 (0.79–0.85) | 0.91 (0.88–0.94) |
| Institutionalized | Yes vs. no | 0.57 (0.55–0.59) | 0.72 (0.69–0.75) |
| Dialysis facility characteristics and ESRD network | |||
| Dialysis chain affiliation | DaVita | 1.31 (1.27–1.35) | 1.27 (1.23–1.32) |
| Fresenius | 1.14 (1.11–1.17) | 1.08 (1.05–1.12) | |
| Midsized | 1.07 (1.03–1.11) | 1.05 (1.01–1.09) | |
| Small/nonchain | Reference | ||
| Hospital affiliation | Hospital based vs. Freestanding | 0.87 (0.83–0.91) | 0.97 (0.91–1.04) |
| Dialysis facility ownership | For profit vs. nonprofit | 1.11 (1.08–1.15) | 1.01 (0.97–1.06) |
| ESRD networkb | Southern California network | Reference | |
| (CT) network of New Englandb | 1.01 (0.95–1.07) | 1.11 (1.03–1.19) | |
| (NY) network of NYb | 0.91 (0.86–0.96) | 1.09 (1.03–1.16) | |
| (FL) ESRD network of FLc | 0.79 (0.76–0.83) | 0.82 (0.78–0.87) | |
| (IL) Renal network of ILc | 0.79 (0.74–0.83) | 0.87 (0.81–0.92) | |
| Community (county) characteristics | |||
| % With high school diploma | >12.9 (median) vs. ≤12.9 | 1.05 (1.03–1.07) | 1.06 (1.03–1.08) |
| Unemployment rate | >4.7% (median) vs. ≤4.7% | 0.97 (0.95–0.99) | 0.98 (0.96–1.00) |
| % Urban | >80.2 (median) vs. ≤80.2 | 1.01 (0.99–1.03) | 1.04 (1.01–1.06) |
| % White | >70.3 (median) vs. ≤70.3 | 1.01 (0.99–1.03) | 1.04 (1.01–1.06) |
AVF, arteriovenous fistula; BMI, body mass index; CT, Connecticut; ESRD, end-stage renal disease; FL, Florida; HR, hazard ratio; IL, Illinois; NY, New York.
a
All were adjusted in the multivariate analysis. Two additional patient-level covariates (diabetes on insulin and size of dialysis facility) and 3 area-level covariates (percent without insurance, median household income, and percent below poverty level) were found to be nonsignificant in both univariate and multivariate analyses.
b
Individual ESRD networks were adjusted in the model. Two ESRD networks with highest AVF use.
c
Two networks with lowest AVF use (18 networks).