@article {1385, title = {Comparison of risk prediction using the CKD-EPI equation and the MDRD study equation for estimated glomerular filtration rate.}, journal = {JAMA}, volume = {307}, year = {2012}, month = {2012 May 09}, pages = {1941-51}, abstract = {

CONTEXT: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation more accurately estimates glomerular filtration rate (GFR) than the Modification of Diet in Renal Disease (MDRD) Study equation using the same variables, especially at higher GFR, but definitive evidence of its risk implications in diverse settings is lacking.

OBJECTIVE: To evaluate risk implications of estimated GFR using the CKD-EPI equation compared with the MDRD Study equation in populations with a broad range of demographic and clinical characteristics.

DESIGN, SETTING, AND PARTICIPANTS: A meta-analysis of data from 1.1 million adults (aged >= 18 years) from 25 general population cohorts, 7 high-risk cohorts (of vascular disease), and 13 CKD cohorts. Data transfer and analyses were conducted between March 2011 and March 2012.

MAIN OUTCOME MEASURES: All-cause mortality (84,482 deaths from 40 cohorts), cardiovascular mortality (22,176 events from 28 cohorts), and end-stage renal disease (ESRD) (7644 events from 21 cohorts) during 9.4 million person-years of follow-up; the median of mean follow-up time across cohorts was 7.4 years (interquartile range, 4.2-10.5 years).

RESULTS: Estimated GFR was classified into 6 categories (>=90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m(2)) by both equations. Compared with the MDRD Study equation, 24.4\% and 0.6\% of participants from general population cohorts were reclassified to a higher and lower estimated GFR category, respectively, by the CKD-EPI equation, and the prevalence of CKD stages 3 to 5 (estimated GFR <60 mL/min/1.73 m(2)) was reduced from 8.7\% to 6.3\%. In estimated GFR of 45 to 59 mL/min/1.73 m(2) by the MDRD Study equation, 34.7\% of participants were reclassified to estimated GFR of 60 to 89 mL/min/1.73 m(2) by the CKD-EPI equation and had lower incidence rates (per 1000 person-years) for the outcomes of interest (9.9 vs 34.5 for all-cause mortality, 2.7 vs 13.0 for cardiovascular mortality, and 0.5 vs 0.8 for ESRD) compared with those not reclassified. The corresponding adjusted hazard ratios were 0.80 (95\% CI, 0.74-0.86) for all-cause mortality, 0.73 (95\% CI, 0.65-0.82) for cardiovascular mortality, and 0.49 (95\% CI, 0.27-0.88) for ESRD. Similar findings were observed in other estimated GFR categories by the MDRD Study equation. Net reclassification improvement based on estimated GFR categories was significantly positive for all outcomes (range, 0.06-0.13; all P < .001). Net reclassification improvement was similarly positive in most subgroups defined by age (<65 years and >=65 years), sex, race/ethnicity (white, Asian, and black), and presence or absence of diabetes and hypertension. The results in the high-risk and CKD cohorts were largely consistent with the general population cohorts.

CONCLUSION: The CKD-EPI equation classified fewer individuals as having CKD and more accurately categorized the risk for mortality and ESRD than did the MDRD Study equation across a broad range of populations.

}, keywords = {African Continental Ancestry Group, Aged, Algorithms, Asian Continental Ancestry Group, Cardiovascular Diseases, Cohort Studies, Decision Support Techniques, European Continental Ancestry Group, Female, Glomerular Filtration Rate, Humans, Kidney Failure, Chronic, Male, Middle Aged, Models, Theoretical, Risk Assessment, Sex Factors}, issn = {1538-3598}, doi = {10.1001/jama.2012.3954}, author = {Matsushita, Kunihiro and Mahmoodi, Bakhtawar K and Woodward, Mark and Emberson, Jonathan R and Jafar, Tazeen H and Jee, Sun Ha and Polkinghorne, Kevan R and Shankar, Anoop and Smith, David H and Tonelli, Marcello and Warnock, David G and Wen, Chi-Pang and Coresh, Josef and Gansevoort, Ron T and Hemmelgarn, Brenda R and Levey, Andrew S} } @article {6796, title = {A Meta-analysis of the Association of Estimated GFR, Albuminuria, Diabetes Mellitus, and Hypertension With Acute Kidney Injury.}, journal = {Am J Kidney Dis}, volume = {66}, year = {2015}, month = {2015 Oct}, pages = {602-12}, abstract = {

BACKGROUND: Diabetes mellitus and hypertension are risk factors for acute kidney injury (AKI). Whether estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio (ACR) remain risk factors for AKI in the presence and absence of these conditions is uncertain.

STUDY DESIGN: Meta-analysis of cohort studies.

SETTING \& POPULATION: 8 general-population (1,285,045 participants) and 5 chronic kidney disease (CKD; 79,519 participants) cohorts.

SELECTION CRITERIA FOR STUDIES: Cohorts participating in the CKD Prognosis Consortium.

PREDICTORS: Diabetes and hypertension status, eGFR by the 2009 CKD Epidemiology Collaboration creatinine equation, urine ACR, and interactions.

OUTCOME: Hospitalization with AKI, using Cox proportional hazards models to estimate HRs of AKI and random-effects meta-analysis to pool results.

RESULTS: During a mean follow-up of 4 years, there were 16,480 episodes of AKI in the general-population and 2,087 episodes in the CKD cohorts. Low eGFRs and high ACRs were associated with higher risks of AKI in individuals with or without diabetes and with or without hypertension. When compared to a common reference of eGFR of 80mL/min/1.73m(2) in nondiabetic patients, HRs for AKI were generally higher in diabetic patients at any level of eGFR. The same was true for diabetic patients at all levels of ACR compared with nondiabetic patients. The risk gradient for AKI with lower eGFRs was greater in those without diabetes than with diabetes, but similar with higher ACRs in those without versus with diabetes. Those with hypertension had a higher risk of AKI at eGFRs>60mL/min/1.73m(2) than those without hypertension. However, risk gradients for AKI with both lower eGFRs and higher ACRs were greater for those without than with hypertension.

LIMITATIONS: AKI identified by diagnostic code.

CONCLUSIONS: Lower eGFRs and higher ACRs are associated with higher risks of AKI among individuals with or without either diabetes or hypertension.

}, keywords = {Acute Kidney Injury, Adult, Aged, Comorbidity, Diabetes Mellitus, Disease Progression, Female, Glomerular Filtration Rate, Humans, Hypertension, Incidence, Kidney Failure, Chronic, Male, Middle Aged, Prognosis, Renal Insufficiency, Chronic}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2015.02.338}, author = {James, Matthew T and Grams, Morgan E and Woodward, Mark and Elley, C Raina and Green, Jamie A and Wheeler, David C and de Jong, Paul and Gansevoort, Ron T and Levey, Andrew S and Warnock, David G and Sarnak, Mark J} }