Table 1.
Baseline characteristics of cohort by time period
| Characteristic | All | Time Period
|
P-value for trend | ||||
|---|---|---|---|---|---|---|---|
| 85–89 | 90–94 | 95–99 | 00–04 | 05–09 | |||
| N | 554 | 84 | 76 | 131 | 172 | 91 | -- |
|
| |||||||
| Median age, years (IQR) | 60 (47–71) | 62 (45–70) | 61 (43–68) | 64 (49–72) | 58 (47–71) | 58 (46–68) | 0.98 |
|
| |||||||
| Female, % | 47% | 46% | 54% | 45% | 49% | 42% | 0.42 |
|
| |||||||
| Race, % | |||||||
| White | 85% | 87% | 86% | 91% | 83% | 79% | 0.15 |
| Black | 9% | 12% | 8% | 8% | 9% | 9% | 0.61 |
| Other | 6% | 1% | 7% | 2% | 8% | 12% | 0.02 |
|
| |||||||
| Diagnosis, % | |||||||
| GPA | 19% | 15% | 18% | 18% | 20% | 24% | 0.15 |
| MPA | 56% | 58% | 51% | 56% | 55% | 58% | 0.82 |
| RLV | 25% | 26% | 30% | 26% | 24% | 18% | 0.10 |
|
| |||||||
| ANCA ELISA, % | |||||||
| PR3/C | 40% | 44% | 33% | 43% | 41% | 37% | 0.78 |
| MPO/P | 60% | 56% | 67% | 57% | 59% | 63% | |
|
| |||||||
| Organ Involvement, % | |||||||
| Lung | 49% | 50% | 38% | 49% | 52% | 53% | 0.23 |
| Joint | 41% | 36% | 36% | 40% | 44% | 48% | 0.05 |
| Upper respiratory | 35% | 36% | 29% | 34% | 33% | 44% | 0.28 |
| Skin | 23% | 21% | 26% | 25% | 19% | 19% | 0.37 |
| Gastrointestinal | 11% | 15% | 16% | 12% | 8% | 4% | 0.005 |
| Neurologic | 10% | 14% | 8% | 15% | 8% | 7% | 0.13 |
| Muscle | 3% | 6% | 7% | 2% | 3% | 0% | 0.06 |
|
| |||||||
| Pre-existing AAV prior to diagnostic biopsy, % | 10% | 7% | 11% | 10% | 10% | 11% | 0.45 |
|
| |||||||
| Median duration of follow-up, months (IQR) | 31 (11–67) | 35 (11–68) | 32 (7–72) | 23 (7–49) | 29 (14–91) | 38 (11–59) | 0.98 |
|
| |||||||
| Tertiary care, % (vs community practice) | 48% | 30% | 26% | 40% | 55% | 82% | < 0.001 |
|
| |||||||
| Median serum creatinine, mg/dL (IQR) | 3.6 (2–5.9) | 4.8 (3–8.6) | 3.7 (2.1–6.4) | 4.1 (2.3–6.1) | 3.2 (1.8–5.1) | 2.8 (1.6–4.8) | < 0.001 |
|
| |||||||
| Median Glomerular Filtration Rate, ml/min/1.73 m2 (IQR)* | 16 (9–32) | 11 (7–20) | 16 (8–30) | 14 (8–29) | 17 (11–37) | 23 (12–37) | < 0.001 |
|
| |||||||
| Used plasma exchange, % | 16% | 2% | 4% | 10% | 22% | 40% | < 0.001 |
|
| |||||||
| Cyclophosphamide | |||||||
| Ever used, % | 89% | 73% | 80% | 90% | 95% | 99% | < 0.001 |
| Dates of use available, % | 79% | 8% | 72% | 88% | 91% | 96% | < 0.001 |
|
| |||||||
| Median duration of cyclophosphamide, months (IQR) | 7 (4–13) | 17 (14–20) | 8 (5–21) | 7 (5–15) | 7 (6–13) | 6 (4–8) | 0.009 |
*
Glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) formula. AAV, ANCA-associated vasculitis. ANCA, anti-neutrophil cytoplasmic antibody. GPA, granulomatosis with polyangiitis. IQR, interquartile range. MPA, microscopic polyangiitis. MPO/P, myeloperoxidase antibody and/or perinuclear pattern. PR3/C, proteinase 3 antibody and/or cytoplasmic pattern. RLV, renal-limited vasculitis.