SUPPLEMENTAL MATERIAL
List of GFR estimating equations
Supplemental Table 1. Availability of eGFRBIS2 values by sex and age strata
Supplemental Table 2. Sensitivity analysis, excluding all cases with nosocomial acute kidney injury during follow-up. Linear mixed-effects models for the five eGFR equations, pooled results of the multiple imputed data.
Supplemental Figure 1. Available eGFRBIS2 values in the BIS cohort over the entire observation.
Supplemental Figure 2. Sensitivity analysis for the course of eGFRBIS2 1) excluding cases with early lost-to-follow-up (LOF) defined as death, LOF or only phone visit(s) after baseline or the first follow-up, and 2) restricting analysis to cases with all 4 follow-up visits excluding phone visits.
List of GFR estimating equations
CKD-EPI creatinine equation (race-free)
Male: 142 x min(Scr/0.9,1)-0.302 x max(Scr/0.9,1)-1.200 x 0.9938age
Female: 142 x min(Scr/0.7,1)-0.241 x max(Scr/0.7,1)-1.200 x 0.9938age x 1.012 CKD-EPI cystatin C equation (race-free)
Female or male ≤0.8 mg/L: 133 × (Scys/0.8)−0.499 × 0.996Age [× 0.932 if female]
Female or male >0.8 mg/L: 133 × (Scys/0.8)−1.328 × 0.996Age [× 0.932 if female]
CKD-EPI creatinine–cystatin C equation (race-free) Male: 135 x min(Scr/0.9,1)-0.144 x max(Scr/0.9,1)-0.544
x min(Scys/0.8,1)-0.323 x max(Scys/0.8,1)-0.778 x 0.9961age Female: 135 x min(Scr/0.7,1)-0.219 x max(Scr/0.7,1)-0.544
x min(Scys/0.8,1)-0.323 x max(Scys/0.8,1)-0.778 x 0.9961age x 0.963 BIS2 creatinine–cystatin C equation
767 x Scys-0.61 x Scr-0.40 x age-0.57 [x 0.87 if female]
EKFC creatinine equation (only rules relevant for ages≥70 years) For ages >25 years:
Males: Q = 80 μmol/L (0.90 mg/dL) Females: Q = 62 μmol/L (0.70 mg/dL) For ages >40 years:
Scr/Q<1: 107.3 x (Scr/Q)−0.322 × 0.990(Age − 40) Scr/Q≥1: 107.3 × (Scr/Q)−1.132 × 0.990(Age − 40)
Supplemental Table 1. Availability of eGFRBIS2 values by sex and age strata Age strata (years)
70-74 75-79 80-84 85-89 90-94 95-99 ≥100 N=7,134 eGFR
values (100%)
911 (13%)
1,878 (26%)
1,892 (27%)
1,416 (20%)
815 (11%)
214 (3%)
8 (<0.1%) Male
(n=3,298 values, 100%)
384 (12%)
792 (24%)
902 (27%)
670 (20%)
433 (13%)
113 (3%)
4 (<0.1%) Female
(n=3,836 values, 100%)
527 (14%)
1,086 (28%)
990 (26%)
746 (19%)
382 (10%)
101 (3%)
4 (<0.1%) Participants with
eGFRBIS2 values (N) 573 955 1,065 827 489 142 7
Male 251 416 491 394 254 78 4
Female 322 539 574 433 235 64 3
Supplemental Table 2. Sensitivity analysis, excluding all cases with nosocomial acute kidney injury during follow-up. Mixed-effects models for the five eGFR equations; pooled results of the multiple imputed data. Shown are parameter estimates with 95% confidence intervals in brackets. Non- significant factors are shown in italic.
BIS2(crea/cysC) CKD-Epi(Crea/CysC) CKD-Epi(CysC) CKD-Epi(crea) EKFC(crea)
Male
Intercept 54.5
(54.0;55.1)
65.3 (64.5;66.2)
57.5 (56.7;58.3)
68.1 (67.3;68.9)
57.1 (56.5;57.7)
Age (year) -1.3
(-1.4;-1.2)
-1.6 (-1.7;-1.4)
-1.8 (-1.9;-1.6)
-1.1 (-1.3;-1.0)
-1.1 (-1.3;-1.0) Age quadratic term 0.02
(0.001;0.03)
0.02 (-0.006;0.04)
0.03 (0.01;0.05)
0.0007 (-0.02;0.02)
0.004 (-0.01;0.02) Female
Intercept 52.8
(52.2;53.3)
63.6 (62.9;64.4)
55.7 (55.0;56.5)
66.6 (61.7;63.1)
55.2 (54.6;55.7)
Age (year) -1.2
(-1.3;-1.1)
-1.5 (-1.6;-1.4)
-1.6 (-1.8;-1.5)
-1.1 (-1.3;-1.0)
-1.1 (-1.2;-1.0) Age quadratic term 0.02
(0.005;0.03)
0.02 (-0.0009;0.04)
0.04 (0.02;0.06)
-0.002 (-0.02;0.02)
0.002 (-0.01;0.02)
Supplemental Figure 1: Available eGFRBIS2 values in the BIS cohort over the entire observation (baseline and 4 biannual follow-up visits); shown are numbers of eGFR values and their availability relative to the documented follow-up visits. Dropout cases were considered as „death“, if the participant died before or within 3 months of the next intended follow-up (2*x years after the baseline visit); all alive participants or later deaths were considered as lost to follow-up (LOF) with regard to the next pending follow-up. Participants who missed only single follow-ups in between (n=69 visits) are displayed as “no-show”.
Taking into account the death dates and thereby omitting missed visits that would have been due within 3 months before death, a maximum of 8,491
Supplemental Figure 2. Sensitivity analysis for the course of eGFRBIS2 1) excluding cases with early lost-to-follow-up defined as death, LOF or only phone visit(s) after baseline or the first follow-up (n=1,453, dark blue/red), and 2) restricting analysis to cases with all 4 follow-up visits excluding phone visits (n=861, light blue/red) for A) men and B) women; 95% confidence intervals are displayed as dotted lines. The eGFR course estimated with all cases (see also Figure 2) is shown as black line.
When running the eGFR estimation restricted to cases with at least two follow-up visits, and restricted to cases with all 4 follow-up visits, the shape
