Table 1.
Baseline characteristics before and after weighting in the assisted peritoneal dialysis and hemodialysis groups
| Variable | Before Weighting | After Weighting | ||||
|---|---|---|---|---|---|---|
| Assisted PD, n=203 | HD, n=872 | Standardized Difference | Assisted PD, n=203 | HD,a n=198 | Standardized Difference | |
| Age, yr, mean (SD) | 68.9 (13.2) | 64.2 (15.7) | 0.80 | 68.9 (13.2) | 68.8 (6.6) | 0.02 |
| Men, % | 56 | 62.2 | 0.12 | 56 | 59 | 0.06 |
| Race, white, % | 86 | 90 | 0.12 | 86 | 87 | 0.03 |
| Comorbidity, % | ||||||
| Diabetes | 52 | 52 | 0.01 | 52 | 50 | 0.05 |
| CAD | 34 | 34 | 0 | 34 | 33 | 0.03 |
| CHF | 23 | 27 | 0.10 | 23 | 21 | 0.04 |
| Other cardiac | 24 | 29 | 0.11 | 24 | 23 | 0.02 |
| Cerebrovascular | 17 | 17 | 0.01 | 17 | 18 | 0.01 |
| PVD | 13 | 17 | 0.11 | 13 | 14 | 0.02 |
| Cancer | 14 | 18 | 0.11 | 14 | 15 | 0.03 |
| History of GI bleed | 5.9 | 8.0 | 0.08 | 5.9 | 7.0 | 0.04 |
| Body mass index, mean (SD) | 28.1 (10.2) | 31.4 (30.0) | 0.18 | 28.1 (10.2) | 27.8 (3.86) | 0.04 |
| ADG, mean (SD) | 10.5 (3.76) | 10.9 (3.63) | 0.10 | 10.5 (3.76) | 10.5 (1.67) | 0.01 |
| Hemoglobin before start, g/dl, mean (SD) | 10.7 (1.5) | 9.5 (1.7) | 0.69 | 10.7 (1.5) | 10.6 (0.78) | 0.07 |
| Serum albumin before start, g/dl, mean (SD) | 3.7 (0.5) | 3.4 (1.4) | 0.29 | 3.7 (0.5) | 4.0 (1.6) | 0.15 |
| eGFR, ml/min per 1.73 m2, mean (SD) | 9.0 (4.6) | 8.6 (6.0) | 0.07 | 9.0 (4.6) | 8.8 (2.3) | 0.05 |
| Neighborhood income quintile,b % | ||||||
| 1 | 22 | 23 | 0.19 | 22 | 25 | 0.14 |
| 2 | 23 | 19 | 0.19 | 23 | 23 | 0.14 |
| 3 | 21 | 17 | 0.19 | 21 | 18 | 0.14 |
| 4 | 18 | 20 | 0.19 | 18 | 15 | 0.14 |
| 5 | 16 | 22 | 0.19 | 16 | 18 | 0.14 |
| Rural resident | 17 | 12.7 | 0.09 | 17 | 15 | 0.06 |
| ≥4 mo Nephrology care before start, % | 97 | 76 | 0.48 | 97 | 96 | 0.03 |
| ≥12 mo Nephrology care before start, % | 91 | 65 | 0.52 | 91 | 86 | 0.13 |
| Nephrology visits in prior year, mean (SD) | 13.8 (6.3) | 10.2 (6.7) | 0.59 | 13.8 (6.3) | 14.3 (5.1) | 0.08 |
| Family physician visits in prior year, mean (SD) | 12.6 (14.1) | 14.7 (16.1) | 0.08 | 12.6 (14.1) | 12.6 (5.9) | 0.01 |
| Hospital visits in prior year, mean (SD) | 0.92 (1.38) | 1.47 (1.51) | 0.38 | 0.92 (1.38) | 0.83 (0.7) | 0.08 |
| Hospital days in prior year if admitted, mean (SD) | 13.2 (15.4) | 22.2 (25.1) | 0.37 | 13.2 (15.4) | 15.5 (6.3) | 0.20 |
| Inpatient start, % | 10.8 | 53.6 | 0.91 | 10.8 | 12.6 | 0.06 |
Standardized differences of >0.10 are generally considered meaningful. PD, peritoneal dialysis; HD, hemodialysis; CAD, coronary artery disease; CHF, congestive heart failure; PVD, peripheral vascular disease; GI, gastrointestinal; ADG, John Hopkins Aggregated Diagnosis Group.
The weighting procedure used age, sex, race, comorbidities, ADG, body mass index, predialysis laboratory values, eGFR, income, rural residence, predialysis care, prior visits with nephrologist and family physician, inpatient start, dialysis program, and year of dialysis start; 872 individual patients contributed to the analyses, but after weighting, the sample size was equivalent to 198 patients. However, they were well balanced in terms of baseline covariates.
Neighborhood income quintile is a household size–adjusted measure of household income on the basis of the 2006 Census data. The quintiles were defined within each neighborhood and not across the entire province to minimize the effect of large differences in housing costs and ensure an equal percentage of the population in each income quintile.