Table 3.
Associations between lifetime stone event rate and laboratory measurements after adjusting for age at 1st stone event, among patients with at least 1 stone event.
| Laboratory Characteristic* | N | Lifetime Stone Event rate | |
|---|---|---|---|
| IRR (95% CI) | P-value | ||
| Urine Oxalate concentration (per 1 unit) | 52 | 0.38 (0.25 to 0.57) | <0.001 |
| Urine Calcium concentration (per 100 units) | 49 | 1.02 (0.86 to 1.20) | 0.84 |
| Urine Calcium* Urine Oxalate concentration (per 100 units) | 48 | 0.87 (0.76 to 0.99) | 0.041 |
| Urine Oxalate (per 1.73m2/24hr) | 53 | 0.53 (0.34 to 0.82) | 0.005 |
| Urine Citrate (per 10,000 1.73m2/24hr) | 48 | 1.02 (0.86 to 1.20) | 0.84 |
| Urine Calcium (per 100 1.73m2/24hr) | 47 | 1.13 (0.94 to 1.36) | 0.18 |
| Ca OX Supersaturation (per 1 unit) | 20 | 1.23 (1.16 to 1.32) | <0.001 |
| Urine Calcium* Urine Oxalate (per 100 units) | 47 | 0.96 (0.81 to 1.14) | 0.64 |
| Urine Oxalate/ Urine Citrate (per 0.001 units) | 50 | 0.95 (0.90 to 1.002) | 0.06 |
| Urine Calcium/ Urine Citrate (per 1 unit) | 48 | 0.81 (0.33 to 2.01) | 0.65 |
| 24hr Urine Volume (per 1,000 1.73m2/24hr <15yrs) | 49 | 1.13 (0.98 to 1.30) | 0.09 |
| eGFR at last follow-up (per 10 mL/min/1/.73m2) † | 28 | 1.02 (0.97 to 1.08) | 0.45 |
IRR=Incidence rate ratio.
Incidence rate ratios and P-values were derived using Poisson regression models modeling the number of lifetime stones with log (age at last follow-up) considered an offset term.
*
Laboratory measure is median value across the patient's lifetime unless otherwise specified.
†
eGFR labs were obtained when patients were 15 years of age or older.