/* SAS Code for calculating U25 eGFR */ /* Reference: Pierce CB, Muņoz A, Ng DK, Warady BA, Furth SL, Schwartz GJ. Age- and sex-dependent clinical equations to estimate glomerular filtration rates in children and young adults with chronic kidney disease. Kidney Int. 2021 Apr;99(4):948-956. doi: 10.1016/j.kint.2020.10.047. Epub 2020 Dec 8. [ PMID: 33301749]*/ /* Online calculators access: https://ckid-gfrcalculator.shinyapps.io/eGFR/ or https://qxmd.com/calculate/calculator_822/ckid-u25-egfr-calculator # Input: VARIABLE DESCRIPTION female sex, 0 for male, 1 for female age age, years (value between 1 to 25 years) ht_m height, meters (value between 0.6 and 2 m) sCr Serum creatinine, mg/dL (value between 0.1 and 10 mg/dL) cyc_ifcc IFCC-calibrated Cystatin C, mg/L (value between 0.2-8 and IFCC-calibrated. A non-calibrated Siemens cystatin C value should be multiplied by 1.17 to approximate its equivalent IFCC-calibrated value.) Output: VARIABLE DESCRIPTION eGFRU25scr U25 eGFR based on serum creatinine only eGFRU25cys U25 eGFR based on IFCC-calibrated cystatin c only eGFRU25ave U25 eGFR based on serum creatinine and IFCC-calibrated cystatin c as average of eGFRU25scr and eGFRU25cys */ * SAS Code to calculate CKiD U25eGFR for use in DATA step; *male; if female=0 and age < 12 then do; ckidKscr = 39.0 * (1.008**(age-12)); ckidKcys = 87.2 * (1.011**(age-15)); end; if female=0 and age >= 12 and age <15 then do; ckidKscr = 39.0 * (1.045**(age-12)); ckidKcys = 87.2 * (1.011**(age-15)); end; if female=0 and age >= 15 and age <18 then do; ckidKscr = 39.0 * (1.045**(age-12)); ckidKcys = 87.2 * (0.960**(age-15)); end; if female=0 and age >= 18 then do; ckidKscr = 50.8; ckidKcys = 77.1; end; *female; if female=1 and age < 12 then do; ckidKscr = 36.1 * (1.008**(age-12)); ckidKcys = 79.9 * (1.004**(age-12)); end; if female=1 and age >= 12 and age <18 then do; ckidKscr = 36.1 * (1.023**(age-12)); ckidKcys = 79.9 * (0.974**(age-12)); end; if female=1 and age >= 18 then do; ckidKscr = 41.4; ckidKcys = 68.3; end; eGFRU25scr= ckidKscr * ht_m / sCr ; eGFRU25cys= ckidKcys * (1 / cyc_ifcc) ; eGFRU25ave= (eGFRU25scr + eGFRU25cys)/2; /* END PROGRAM */