Table 2. Nonparametric 95% reference intervals and their 90% confidence limits.
| Variable | Race | N | Median (q1-q3) | Reference Interval (90% confidence limit) | |
|---|---|---|---|---|---|
| Lower | Upper | ||||
| Fasting urine Ca/Cr | Black and White | 815 | 0.08 (0.04 – 0.12) | 0.008 (0.007 – 0.011) | 0.249 (0.232 – 0.274) |
| Black | 352 | 0.05 (0.03 – 0.09) | 0.007 (0.005 – 0.008) | 0.222 (0.165 – 0.275) | |
| White | 463 | 0.09 (0.06 – 0.14) | 0.019 (0.014 – 0.023) | 0.264 (0.238 – 0.293) | |
| 24-hour urine calcium (mg) |
Black and White | 527 | 79 (48 – 118) | 14 (10 – 16) | 214 (205 – 232) |
| Black | 287 | 70 (42 – 111) | 11 (8 – 15) | 197 (186 – 249) | |
| White | 240 | 91 (54 – 132) | 21 (9 – 24) | 221 (214 – 261) | |
| 24-hour urine Ca/Cr×1,000 |
Black and White | 520 | 94 (56 – 140) | 20 (17 – 23) | 268 (252 – 282) |
| Black | 285 | 72 (44 – 108) | 17 (8 – 20) | 189 (178 – 223) | |
| White | 235 | 127 (89 – 179) | 33 (20 – 40) | 291 (275 – 356) | |