The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
Eric Girardin - One of the best experts on this subject based on the ideXlab platform.
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Quadratic Formula: a new pediatric advance for glomerular filtration rate estimation
Revue medicale suisse, 2014Co-Authors: Hassib Chehade, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:A new Formula for glomerular filtration rate estimation in pediatric population from 2 to 18 years has been developed by the University Unit of Pediatric Nephrology. This Quadratic Formula, accessible online, allows pediatricians to adjust drug dosage and/or follow-up renal function more precisely and in an easy manner.
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new combined serum creatinine and cystatin c Quadratic Formula for gfr assessment in children
Clinical Journal of The American Society of Nephrology, 2014Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:BACKGROUND AND OBJECTIVES: The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. RESULTS: The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P<0.001) increased the κ coefficient to 0.56 and the Quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC Quadratic Formula was derived and internally validated using the cross-validation technique. This Quadratic Formula significantly outperformed the combined Schwartz Formula, which was biased for an iGFR≥91 ml/min per 1.73 m(2). CONCLUSIONS: This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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New Combined Serum Creatinine and Cystatin C Quadratic Formula for GFR Assessment in Children
Clinical journal of the American Society of Nephrology : CJASN, 2013Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:Summary Background and objectives The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)– and serum creatinine (SCreat)–derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. Design, setting, participants, & measurements Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR ( i.e. , logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. Results The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly ( P 2 . Conclusions This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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comparison of the glomerular filtration rate in children by the new revised schwartz Formula and a new generalized Formula
Kidney International, 2013Co-Authors: Francois Cachat, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Eric Girardin, Mohamed Faouzi, Hassib ChehadeAbstract:The most widely used Formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz Formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75ml/min × 1.73m 2 . Here we assessed the accuracy of the Schwartz Formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear Quadratic regression model was fitted and a more accurate Formula was derived. This Quadratic Formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl)) 2 +0.48 × age (years)-(21.53 in males or 25.68 in females). This Formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz Formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103ml/min × 1.73m 2 , but significantly unreliable for higher values. For an accuracy of 20 percent, the Quadratic Formula was significantly better than the Schwartz Formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new Quadratic Formula could replace the revised Schwartz Formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.
Hassib Chehade - One of the best experts on this subject based on the ideXlab platform.
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Quadratic Formula: a new pediatric advance for glomerular filtration rate estimation
Revue medicale suisse, 2014Co-Authors: Hassib Chehade, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:A new Formula for glomerular filtration rate estimation in pediatric population from 2 to 18 years has been developed by the University Unit of Pediatric Nephrology. This Quadratic Formula, accessible online, allows pediatricians to adjust drug dosage and/or follow-up renal function more precisely and in an easy manner.
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new combined serum creatinine and cystatin c Quadratic Formula for gfr assessment in children
Clinical Journal of The American Society of Nephrology, 2014Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:BACKGROUND AND OBJECTIVES: The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. RESULTS: The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P<0.001) increased the κ coefficient to 0.56 and the Quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC Quadratic Formula was derived and internally validated using the cross-validation technique. This Quadratic Formula significantly outperformed the combined Schwartz Formula, which was biased for an iGFR≥91 ml/min per 1.73 m(2). CONCLUSIONS: This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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New Combined Serum Creatinine and Cystatin C Quadratic Formula for GFR Assessment in Children
Clinical journal of the American Society of Nephrology : CJASN, 2013Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:Summary Background and objectives The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)– and serum creatinine (SCreat)–derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. Design, setting, participants, & measurements Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR ( i.e. , logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. Results The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly ( P 2 . Conclusions This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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comparison of the glomerular filtration rate in children by the new revised schwartz Formula and a new generalized Formula
Kidney International, 2013Co-Authors: Francois Cachat, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Eric Girardin, Mohamed Faouzi, Hassib ChehadeAbstract:The most widely used Formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz Formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75ml/min × 1.73m 2 . Here we assessed the accuracy of the Schwartz Formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear Quadratic regression model was fitted and a more accurate Formula was derived. This Quadratic Formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl)) 2 +0.48 × age (years)-(21.53 in males or 25.68 in females). This Formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz Formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103ml/min × 1.73m 2 , but significantly unreliable for higher values. For an accuracy of 20 percent, the Quadratic Formula was significantly better than the Schwartz Formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new Quadratic Formula could replace the revised Schwartz Formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.
Salahuddin Ahmad - One of the best experts on this subject based on the ideXlab platform.
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SU‐FF‐T‐493: Can An Addition of a Simple Constant to Linear Quadratic Formula Improve Cell Survival Curve Fits for Some Cell Lines?
Medical Physics, 2009Co-Authors: F Mckenna, Salahuddin AhmadAbstract:Purpose: To investigate the effect of an unrecognized hyper radio‐sensitivity on radiobiological parameters α and β of the linear Quadratic odel. Methods and Materials: A Chinese hamster cell line designated “choaa8” and a lungcancer cell line designated “ncih226” were fitted to the inear Quadratic (LQ) model (lnS = −αD −βD2) and to a simple constant plus linear Quadratic (CLQ) model (lnS = −c −αD −βD2). The χ2/df of each fit was compared to determine which model gives the best fit to the cell survival curve. Results: The linear Quadratic χ2/df for the “choaa8” and the “ncih226” are 1.55 and .095 respectively. The simple constant plus linear Quadratic χ2/df for the “choaa8” and the “ncih226” are 1.18 and .075 respectively. So the addition of a simple constant to the linear Quadratic Formula provides greater than 20% improvement to the survival curve fits. The α/β _ratio for the LQ “choaa8” is 11.0, whereas the α/β _ratio for the CLQ “choaa8” is 5.4. The α/β _ratio for the LQ “ncih226” is 5.1, whereas the α/β _ratio for the CLQ “ncih226” is 0 indicating α = 0. So the addition of a simple constant in the linear QuadraticFormula can have a dramatic effect on the α/β _ratio._ Conclusion: CLQ provided superior fits compared to the LQ for the two data sets mentioned above. The value of the α/β _ratio was heavily dependent on whether or not an addition of a simple constant to linear Quadratic Formula was used. Further work is required to determine if the improved fit is due to actual physical phenomena such as hyper radio‐sensitivity or an alternative explanation like experimental error or noise in the data.
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su ff t 493 can an addition of a simple constant to linear Quadratic Formula improve cell survival curve fits for some cell lines
Medical Physics, 2009Co-Authors: F Mckenna, Salahuddin AhmadAbstract:Purpose: To investigate the effect of an unrecognized hyper radio‐sensitivity on radiobiological parameters α and β of the linear Quadratic odel. Methods and Materials: A Chinese hamster cell line designated “choaa8” and a lungcancer cell line designated “ncih226” were fitted to the inear Quadratic (LQ) model (lnS = −αD −βD2) and to a simple constant plus linear Quadratic (CLQ) model (lnS = −c −αD −βD2). The χ2/df of each fit was compared to determine which model gives the best fit to the cell survival curve. Results: The linear Quadratic χ2/df for the “choaa8” and the “ncih226” are 1.55 and .095 respectively. The simple constant plus linear Quadratic χ2/df for the “choaa8” and the “ncih226” are 1.18 and .075 respectively. So the addition of a simple constant to the linear Quadratic Formula provides greater than 20% improvement to the survival curve fits. The α/β _ratio for the LQ “choaa8” is 11.0, whereas the α/β _ratio for the CLQ “choaa8” is 5.4. The α/β _ratio for the LQ “ncih226” is 5.1, whereas the α/β _ratio for the CLQ “ncih226” is 0 indicating α = 0. So the addition of a simple constant in the linear QuadraticFormula can have a dramatic effect on the α/β _ratio._ Conclusion: CLQ provided superior fits compared to the LQ for the two data sets mentioned above. The value of the α/β _ratio was heavily dependent on whether or not an addition of a simple constant to linear Quadratic Formula was used. Further work is required to determine if the improved fit is due to actual physical phenomena such as hyper radio‐sensitivity or an alternative explanation like experimental error or noise in the data.
Francois Cachat - One of the best experts on this subject based on the ideXlab platform.
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Quadratic Formula: a new pediatric advance for glomerular filtration rate estimation
Revue medicale suisse, 2014Co-Authors: Hassib Chehade, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:A new Formula for glomerular filtration rate estimation in pediatric population from 2 to 18 years has been developed by the University Unit of Pediatric Nephrology. This Quadratic Formula, accessible online, allows pediatricians to adjust drug dosage and/or follow-up renal function more precisely and in an easy manner.
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new combined serum creatinine and cystatin c Quadratic Formula for gfr assessment in children
Clinical Journal of The American Society of Nephrology, 2014Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:BACKGROUND AND OBJECTIVES: The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. RESULTS: The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P<0.001) increased the κ coefficient to 0.56 and the Quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC Quadratic Formula was derived and internally validated using the cross-validation technique. This Quadratic Formula significantly outperformed the combined Schwartz Formula, which was biased for an iGFR≥91 ml/min per 1.73 m(2). CONCLUSIONS: This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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New Combined Serum Creatinine and Cystatin C Quadratic Formula for GFR Assessment in Children
Clinical journal of the American Society of Nephrology : CJASN, 2013Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:Summary Background and objectives The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)– and serum creatinine (SCreat)–derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. Design, setting, participants, & measurements Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR ( i.e. , logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. Results The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly ( P 2 . Conclusions This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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comparison of the glomerular filtration rate in children by the new revised schwartz Formula and a new generalized Formula
Kidney International, 2013Co-Authors: Francois Cachat, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Eric Girardin, Mohamed Faouzi, Hassib ChehadeAbstract:The most widely used Formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz Formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75ml/min × 1.73m 2 . Here we assessed the accuracy of the Schwartz Formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear Quadratic regression model was fitted and a more accurate Formula was derived. This Quadratic Formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl)) 2 +0.48 × age (years)-(21.53 in males or 25.68 in females). This Formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz Formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103ml/min × 1.73m 2 , but significantly unreliable for higher values. For an accuracy of 20 percent, the Quadratic Formula was significantly better than the Schwartz Formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new Quadratic Formula could replace the revised Schwartz Formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.
Dolores Mosig - One of the best experts on this subject based on the ideXlab platform.
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new combined serum creatinine and cystatin c Quadratic Formula for gfr assessment in children
Clinical Journal of The American Society of Nephrology, 2014Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:BACKGROUND AND OBJECTIVES: The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)- and serum creatinine (SCreat)-derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR (i.e., logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. RESULTS: The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly (P<0.001) increased the κ coefficient to 0.56 and the Quadratic model accuracy to 97%. Therefore, a combined SCreat and CysC Quadratic Formula was derived and internally validated using the cross-validation technique. This Quadratic Formula significantly outperformed the combined Schwartz Formula, which was biased for an iGFR≥91 ml/min per 1.73 m(2). CONCLUSIONS: This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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New Combined Serum Creatinine and Cystatin C Quadratic Formula for GFR Assessment in Children
Clinical journal of the American Society of Nephrology : CJASN, 2013Co-Authors: Hassib Chehade, Annesophie Jannot, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Paloma Parvex, Francois Cachat, Eric GirardinAbstract:Summary Background and objectives The estimated GFR (eGFR) is important in clinical practice. To find the best Formula for eGFR, this study assessed the best model of correlation between sinistrin clearance (iGFR) and the solely or combined cystatin C (CysC)– and serum creatinine (SCreat)–derived models. It also evaluated the accuracy of the combined Schwartz Formula across all GFR levels. Design, setting, participants, & measurements Two hundred thirty-eight iGFRs performed between January 2012 and April 2013 for 238 children were analyzed. Regression techniques were used to fit the different equations used for eGFR ( i.e. , logarithmic, inverse, linear, and Quadratic). The performance of each model was evaluated using the Cohen κ correlation coefficient and the percentage reaching 30% accuracy was calculated. Results The best model of correlation between iGFRs and CysC is linear; however, it presents a low κ coefficient (0.24) and is far below the Kidney Disease Outcomes Quality Initiative targets to be validated, with only 84% of eGFRs reaching accuracy of 30%. SCreat and iGFRs showed the best correlation in a fitted Quadratic model with a κ coefficient of 0.53 and 93% accuracy. Adding CysC significantly ( P 2 . Conclusions This study allowed deriving a new combined SCreat and CysC Quadratic Formula that could replace the combined Schwartz Formula, which is accurate only for children with moderate chronic kidney disease.
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comparison of the glomerular filtration rate in children by the new revised schwartz Formula and a new generalized Formula
Kidney International, 2013Co-Authors: Francois Cachat, Blaisejulien Meyrat, Dolores Mosig, Daniel Bardy, Eric Girardin, Mohamed Faouzi, Hassib ChehadeAbstract:The most widely used Formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz Formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75ml/min × 1.73m 2 . Here we assessed the accuracy of the Schwartz Formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear Quadratic regression model was fitted and a more accurate Formula was derived. This Quadratic Formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl)) 2 +0.48 × age (years)-(21.53 in males or 25.68 in females). This Formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz Formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103ml/min × 1.73m 2 , but significantly unreliable for higher values. For an accuracy of 20 percent, the Quadratic Formula was significantly better than the Schwartz Formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new Quadratic Formula could replace the revised Schwartz Formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.
