Table 1.

Patient characteristics in the full cohort, the subcohort used for application of the KFRE, and the subcohort used for the repeated measures analysis

Characteristic% of Patientsa
Full Cohort (N=47,714)Subcohort for Application of the KFRE (n=9998)Subcohort for Repeated Measures Analysis (n=17,259) (74,341 Pairs)b
Age in yr, median (IQR)59.3 (47.2–70.4)71.3 (61.9–79.1)58.9 (49.0–70.1)
Age category, yr
KDIGO CKD PCR category, mg/gc
 A1: <150 (normal/mild)65.845.359.4
 A2: 150–500 (moderate)19.025.420.9
 A3: >500 (severe)15.229.319.7
KDIGO CKD ACR category, mg/gc
 A1: <30 (normal/mild)61.942.454.7
 A2: 30–300 (moderate)23.831.026.4
 A3: >300 (severe)14.326.618.9
KDIGO CKD eGFR category, ml/min per 1.73 m2
 G1: eGFR≥9035.032.1
 G2: eGFR=60–8933.333.4
 G3A: eGFR=45–5912.338.913.2
 G3B: eGFR=30–4411.134.513.5
 G4: eGFR=15–
 G5: eGFR<
Year of ACR/PCR test pair
Laboratory locationd
  • a Unless otherwise indicated.

  • b Percents in this column are calculated on the basis of the number of patients, using characteristics on the date of the earliest pair.

  • c To convert ACR or PCR from milligrams per gram to milligrams per millimole, multiply by 0.113.

  • d In Edmonton, most urine albumin measurements were made using a Siemens Advia 1800 analyzer, with an immunoturbidimetric method. Urine protein was measured using a colorimetric method (pyrogallol red) on a Protein Pointe Scientific analyzer (from September 2013 to December 2016), a Wako analyzer (July 2011 to September 2013), and a Genzyme analyzer (before July 2011). In Calgary, most measurements were made with a Roche Integra analyzer, with albumin measured with an immunoturbidimetric method and protein with a turbidimetric method (benzethonium chloride). Testing at other sites was done using various analyzers and methods, which we were unable to determine in all cases.