| PATIENTS | CONTROLS | |||
|---|---|---|---|---|
| Units/wk | Duration (yr)* | Age started(yr)* | Duration (yr) | Age started (yr) |
| > 0 | 30 (23–36) | 17 (16–18)+ | 30 (23–36) | 16 (15–18) |
| > 40 | 20 (14–27) | 22 (18–30)+ | 22 (16–30) | 19 (17–25) |
| > 80 | 12 (6–19) | 29 (21–38)+ | 13 (7–22) | 25 (18–33) |
| > 120 | 3 (0–12) | 32 (24–41)++ | 4 (0–10) | 28 (21–37) |
| > 160 | 0 (0–7) | 33 (27–41)+++ | 0 (0–7) | 30 (24–39) |
↵* : median (interquartile range). +: p < 0.001, ++: p = 0.02, +++: p = 0.017 by Mann-Whitney test for patients vs controls.