Table 1.
Variation factors used for risk score simulations.
Fig 1.
A. Predicted KFRE variation with eGFR. The black line represents the 2-year KFRE estimate for a 50-year old male with a fixed ACR of 30 g/mol. Upper and lower bounds (dotted lines) represent the 95% confidence interval for KFRE risk based on a biological variation in eGFR of 6.6%. B. Predicted KFRE variation with eGFR and inter-laboratory variation. Upper and lower bounds (dotted lines) represent the 95% confidence interval for KFRE risk based on a biological variation in eGFR of 6.6% combined with a reported inter-laboratory variation of 4.3%.
Fig 2.
A Predicted KFRE variation with ACR concentration. The black line represents the 2-year KFRE estimate for a 50-year old male with a fixed eGFR of 30 mL/min/1.72 m2. Upper and lower bounds (dotted lines) represent the 95% confidence interval for the 2-year KFRE risk based on published ACR-concentration variation from 11.3%. B. Predicted KFRE variation with ACR concentration in combination with inter-laboratory variation. Upper and lower bounds (dotted lines) represent the 95% confidence interval for KFRE risk based published ACR variation combined with a reported inter-laboratory variation of 9.6%.
Fig 3.
Comparison of predicted risk variability using a single laboratory, multiple laboratory with different methods, or averaging serial values.
In all panels, the black lines represent the 2-year KFRE estimate for a 50-year old male at fixed ACRs of 3, 30, and 300 g/mol and the upper and lower dotted lines represent 95% confidence intervals. Left Panels: Predicted KFRE with combined variation in eGFR and ACR analyzed by a single method. Center Panels: Predicted KFRE with combined variation in eGFR, ACR, and laboratory method. Variation includes combined inter-laboratory variation. Right Panels: Predicted reduction in KFRE variation by using averages of serial eGFR and ACR measurement. Inter-laboratory variation was excluded to reflect use of a single laboratory.
Fig 4.
Variation in KFRE using serial eGFR and ACR from patients.
A. Variation in 2-year KFRE with eGFR in patients. Variation was determined by calculating the difference in 2-year KFRE using serial eGFR and ACR values from a given patient. Each point represents the difference in KFRE calculated from two pairs of eGFR and ACR values for a single patient within a 3-month time period. B. The same patient data as panel A, except showing variation in 2-year KFRE with ACR on the x-axis.
Table 2.
Mean variability in KFRE risk*.