The data below are derived from Huang N, Foster M, Lentine K et al. Estimated GFR for living kidney donor evaluation. American Journal of Transplantation [epub ahead of print Nov 23 2015].

##### Step 2: Determine pre-test probability

Result (Pre-test probability based on age, sex and race from US population data)

 Measured GFR Thresholds <60 <70 ≥80 ≥90 Percentage of NHANES participants who had eGFRcr-cys less or above the specified thresholds. If you are interested in the opposite of the threshold (eg < 80), then subtract the value given from 100. 6 12 77 64

You can use the numbers above or a different number based on knowledge of your patient’s medical history. For example, if your patient has a strong family history of CKD, you may wish to alter the pretest probability. If so, write the number to be used as pre-test probability in table below.

 Measured GFR Thresholds <60 <70 ≥80 ≥90

##### Step 3: Calculate the post-test probability

The calculator will look up the likelihood ratio based on the eGFR calculated from the creatinine and cysatin provided above and will compute post-test probability.

 Measured GFR Thresholds <60 <70 ≥80 ≥90 †Post test probability of mGFR above or below the threshold based on eGFRcr. If you are interested in the opposite of the threshold (eg < 80), then subtract the value given from 100. ‡If you also indicated the eGFRcr-cys, the calculator will use the post-test probability from the eGFRcr as the pre-test probability and use it to compute the post-test probability from eGFRcr-cys. If you are interested in the opposite of the threshold (eg < 80), then subtract the value given from 100. Post-test probability from eGFRcr† 94% 94% 94% 94% Post-test probability from eGFRcr-cys‡ 100% 100% 100% 100%

## Summary report

Based on the information supplied:

 Age Sex Race Creatinine Cystatin C Estimated GFR from creatinine ml/min per 1.73 m2 Estimated GFR from creatinine-cystatin C ml/min per 1.73 m2

 Measured GFR Thresholds <60 <70 ≥80 ≥90 †Post test probability of mGFR above or below the threshold based on eGFRcr. If you are interested in the opposite of the threshold (eg < 80), then subtract the value given from 100. ‡If you also indicated the eGFRcr-cys, the calculator will use the post-test probability from the eGFRcr as the pre-test probability and use it to compute the post-test probability from eGFRcr-cys. If you are interested in the opposite of the threshold (eg < 80), then subtract the value given from 100. Pre-test probability Post-test probability from eGFRcr† Post-test probability from eGFRcr-cys‡