BACKGROUND AND OBJECTIVES: All glomerular filtration rate (GFR) estimating equations have been developed from cross-sectional data. The aims of this study were to examine the concordance between use of measured GFR (mGFR) and estimated GFR (eGFR) in tracking changes in kidney function over time among patients with moderately severe chronic kidney disease. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort study of subjects who had been enrolled in the MDRD Study A and who had two or more contemporaneous assessments of mGFR and eGFR (n = 542; mGFR range, 25 to 55 ml/min per 1.73 m(2)) during the chronic phase (month 4 and afterwards). mGFR was based on urinary iothalamate clearance; eGFR was based on the 4-variable MDRD Study equation. Temporal changes in GFR were assessed by within-subject linear regression of time on GFR. RESULTS: Median follow-up time for all subjects was 2.6 yr; median number of GFR measurements was six. The eGFR slope tended to underestimate measured decrements in GFR. The absolute value of the difference in mGFR and eGFR slopes was <or=2 ml/min per 1.73 m(2) per yr among 58.3% of subjects; the remainder of subjects had larger absolute differences. Among the 22 variables studied, none predicted a systematic difference between mGFR slope and eGFR slope. CONCLUSIONS: Although eGFR and mGFR exhibited similar relationships to 22 baseline variables, the overall bias seen in the full cohort suggests that clinicians and researchers should exercise caution when interpreting eGFR slope as a marker of progression of kidney disease.
BACKGROUND AND OBJECTIVES: All glomerular filtration rate (GFR) estimating equations have been developed from cross-sectional data. The aims of this study were to examine the concordance between use of measured GFR (mGFR) and estimated GFR (eGFR) in tracking changes in kidney function over time among patients with moderately severe chronic kidney disease. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort study of subjects who had been enrolled in the MDRD Study A and who had two or more contemporaneous assessments of mGFR and eGFR (n = 542; mGFR range, 25 to 55 ml/min per 1.73 m(2)) during the chronic phase (month 4 and afterwards). mGFR was based on urinary iothalamate clearance; eGFR was based on the 4-variable MDRD Study equation. Temporal changes in GFR were assessed by within-subject linear regression of time on GFR. RESULTS: Median follow-up time for all subjects was 2.6 yr; median number of GFR measurements was six. The eGFR slope tended to underestimate measured decrements in GFR. The absolute value of the difference in mGFR and eGFR slopes was <or=2 ml/min per 1.73 m(2) per yr among 58.3% of subjects; the remainder of subjects had larger absolute differences. Among the 22 variables studied, none predicted a systematic difference between mGFR slope and eGFR slope. CONCLUSIONS: Although eGFR and mGFR exhibited similar relationships to 22 baseline variables, the overall bias seen in the full cohort suggests that clinicians and researchers should exercise caution when interpreting eGFR slope as a marker of progression of kidney disease.
Authors: Andrew D Rule; Timothy S Larson; Erik J Bergstralh; Jeff M Slezak; Steven J Jacobsen; Fernando G Cosio Journal: Ann Intern Med Date: 2004-12-21 Impact factor: 25.391
Authors: Xuelei Wang; Julia Lewis; Lawrence Appel; DeAnna Cheek; Gabriel Contreras; Marquetta Faulkner; Harold Feldman; Jennifer Gassman; Janice Lea; Joel Kopple; Mohammed Sika; Robert Toto; Tom Greene Journal: J Am Soc Nephrol Date: 2006-09-20 Impact factor: 10.121
Authors: Bruce A Perkins; Robert G Nelson; Betsy E P Ostrander; Kristina L Blouch; Andrzej S Krolewski; Bryan D Myers; James H Warram Journal: J Am Soc Nephrol Date: 2005-03-23 Impact factor: 10.121
Authors: Andrew D Rule; Vicente E Torres; Arlene B Chapman; Jared J Grantham; Lisa M Guay-Woodford; Kyongtae T Bae; Saulo Klahr; William M Bennett; Catherine M Meyers; Paul A Thompson; J Philip Miller Journal: J Am Soc Nephrol Date: 2006-02-01 Impact factor: 10.121
Authors: Anthony H Barnett; Stephen C Bain; Paul Bouter; Bengt Karlberg; Sten Madsbad; Jak Jervell; Jukka Mustonen Journal: N Engl J Med Date: 2004-10-31 Impact factor: 91.245
Authors: William F Clark; Jessica M Sontrop; Jennifer J Macnab; Rita S Suri; Louise Moist; Marina Salvadori; Amit X Garg Journal: Clin J Am Soc Nephrol Date: 2011-09-01 Impact factor: 8.237
Authors: Julia Z Xu; Melanie E Garrett; Karen L Soldano; Sean T Chen; Clary B Clish; Allison E Ashley-Koch; Marilyn J Telen Journal: Am J Hematol Date: 2018-09-27 Impact factor: 10.047
Authors: Ian H de Boer; Ronit Katz; Linda F Fried; Joachim H Ix; Jose Luchsinger; Mark J Sarnak; Michael G Shlipak; David S Siscovick; Bryan Kestenbaum Journal: Am J Kidney Dis Date: 2009-09-25 Impact factor: 8.860
Authors: Rebecca Hanratty; Michel Chonchol; L Miriam Dickinson; Brenda L Beaty; Raymond O Estacio; Thomas D Mackenzie; Laura P Hurley; Stuart L Linas; John F Steiner; Edward P Havranek Journal: Nephrol Dial Transplant Date: 2009-11-04 Impact factor: 5.992