Estimated glomerular filtration rate is unreliable in detecting XXXX during follow-up after cystectomy and urinary diversion.

@entity1 @entity177 @entity8680
PURPOSE: To evaluate the accuracy of estimated glomerular filtration rate (eGFR) against the reference standard of isotopic GFR (iGFR) in monitoring renal function during follow-up after cystectomy and urinary diversion. METHODS: @entity1 who had undergone cystectomy and ileal conduit urinary diversion at two centres between August 2001 and August 2006 were identified. eGFR calculated using the MDRD formula was compared to @entity8680 EDTA measured iGFR values measured at similar time-points during follow-up. RESULTS: Six hundred and fourteen paired iGFR and eGFR results were analysed from 166 @entity1 (18  % female, median age 70  years). There was a significant difference between paired iGFR and eGFR measurements (p  <  0.0001) with a mean bias of +1.8  mls/min/1.73m(2) (SD 18.0) and a 95  % limit of agreement of -33.5 to 37.2  mls/min/1.73m(2). iGFR and eGFR values converged at a GFR of approximately 45  mls/min/1.73m(2). 70.6  % of @entity1 experienced a @entity177 greater than expected (>0.58  mls/min/1.73m(2)/year). In 22.4  % of these @entity1 , a decline of greater than 10  % in iGFR occurred that was undetected by eGFR measurements, which overestimated GFR. There was no significant relationship between @entity1 height, weight or body mass index and the accuracy of eGFR measurements. CONCLUSIONS: iGFR measurement is recommended following ileal conduit urinary diversion if early signs of @entity177 are to be detected. eGFR overestimates GFR in critically relevant ranges and fails to detect loss in a clinically significant proportion of @entity1 .
