Martin J. Schreiber

Prediction of outcome in acute renal failure

In an attempt to predict outcome in acute renal failure (ARF) we have utilized multiple logistic regression to analyze clinical data from 151 patients with ARF seen over a 15-month period. Recovery of renal function occurred in 60% of patients with a 58% survival. Our analysis demonstrated sepsis, respiratory failure, and oliguria to be the major predictors of nonrecovery of renal function. A logistic equation was generated for prediction of outcome and was validated in a second independent group of patients with ARF. Prediction of outcome could be achieved with a sensitivity of 75% and a specificity of 80%. Maximum sensitivity (100%) was associated with a 17% specificity, while maximum specificity (98%) yielded a sensitivity of 20%.

Low 25-Hydroxyvitamin D Levels and Mortality in Non–Dialysis-Dependent CKD

BACKGROUND Low 25-hydroxyvitamin D (25[OH]D) levels are common in patients with non-dialysis-dependent chronic kidney disease (CKD). The associations between low 25(OH)D levels and mortality in non-dialysis-dependent patients with CKD are unclear. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS Patients with stages 3-4 CKD (estimated glomerular filtration rate, 15-59 mL/min/1.73 m(2); n = 12,673) who had 25(OH)D levels measured after the diagnosis of CKD in the Cleveland Clinic Health System. PREDICTOR 25(OH)D levels categorized into 3 groups: <15, 15-29, and ≥30 ng/mL. OUTCOMES We examined factors associated with low 25(OH)D levels and associations between low 25(OH)D levels and all-cause mortality (ascertained using the Social Security Death Index and our electronic medical record) using logistic regression, Cox proportional hazard models, and Kaplan-Meier survival curves. MEASUREMENTS 25(OH)D was measured using chemiluminescence immunoassay. RESULTS Of 12,763 patients with CKD, 15% (n = 1,970) had 25(OH)D levels <15 ng/mL, whereas 45% (n = 5,749) had 25(OH)D levels of 15-29 ng/mL. Male sex, African American race, diabetes, coronary artery disease, and lower estimated glomerular filtration rate were associated significantly with 25(OH)D level <30 ng/mL. A graded increase in risk of 25(OH)D level <30 ng/mL was evident across increasing body mass index levels. Patients who had 25(OH)D levels measured in fall through spring had higher odds for 25(OH)D levels <30 ng/mL. After covariate adjustment, patients with CKD with 25(OH)D levels <15 ng/mL had a 33% increased risk of mortality (95% CI, 1.07-1.65). The group with 25(OH)D levels of 15-29 ng/mL did not show a significantly increased risk of mortality (HR, 1.03; 95% CI, 0.86-1.22) compared with patients with 25(OH)D levels ≥30 ng/mL. LIMITATIONS Single-center observational study, lack of data for albuminuria and other markers of bone and mineral disorders, and attrition bias. CONCLUSIONS 25(OH)D level <15 ng/mL was associated independently with all-cause mortality in non-dialysis-dependent patients with CKD.

Overweight, obesity and intentional weight loss in chronic kidney disease: NHANES 1999–2006

OBJECTIVE:Obesity and chronic kidney disease (CKD) have emerged as major public health problems. We aimed to examine: (a) lifestyle and behavioral factors, (b) factors related to pursuing weight loss and (c) weight loss modalities pursued by CKD and non-CKD individuals who are overweight and obese.METHODS:Cross-sectional analysis of 10 971 overweight and obese adult participants in the National Health and Nutrition Examination Surveys conducted between 1999 and 2006. We examined the differences in lifestyle and behavioral factors between CKD and non-CKD participants and factors associated with pursuing weight loss using survey regression models.RESULTS:The total daily energy intake of the CKD population was lower than the non-CKD group (1987 kcal per day versus 2063 kcal per day, P=0.02) even after adjusting for relevant covariates. However, the percentage of energy derived from protein was similar between the groups. Sixty six percent of the CKD population did not meet the minimum recommended leisure time physical activity goals compared with 57% among non-CKD (P<0.001). Fifty percent of CKD participants pursued weight loss (vs fifty-five percent of non-CKD individuals, P=0.01), but the presence of CKD was not independently associated with the pursuit of weight loss in the multivariate model. Among participants pursuing weight loss, modalities including dietary interventions utilized by CKD and non-CKD participants were similar. Eight percent of CKD participants used medications to promote weight loss.CONCLUSIONS:Among the overweight and obese population, lifestyle and behavioral factors related to obesity and weight loss are similar between CKD and non-CKD participants. Insufficient data exist on the beneficial effects of intentional weight loss in CKD and these data show that a significant proportion of the CKD population use diets that may have high-protein content and medications to promote weight loss that may be harmful. Future clinical trials evaluating the efficacy and optimal modalities to treat obesity in the CKD population are warranted.

Implications of the CKD-EPI GFR estimation equation in clinical practice.

BACKGROUND AND OBJECTIVES Chronic kidney disease (CKD) is a significant public health problem whose diagnosis and staging relies upon GFR-estimating equations, including the new CKD-EPI equation. CKD-EPI demonstrated superior performance compared with the existing MDRD equation but has not been applied to a healthcare system. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We identified 53,759 patients with stages 3 to 5 CKD on the basis of either MDRD or CKD-EPI equations using two eGFR values <60 ml/min per 1.73 m² > 90 days apart from an outpatient setting. We compared patient characteristics, presence of related diagnosis codes, and time CKD classification between equations. RESULTS The number of patients identified with CKD decreased 10% applying CKD-EPI versus MDRD. Changes varied substantially by patient characteristics including a 35% decrease among patients < 60 years and a 10% increase among patients > 90 years. Women, non-African Americans, nondiabetics, and obese patients were less likely to be classified on the basis of CKD-EPI. Time to CKD classification was significantly longer with CKD-EPI among younger patients. 14% of patients identified with CKD on the basis of either estimating equation also had a related ICD-9 diagnosis, ranging from 19% among patients < 60 years to 7% among patients > 90 years. CONCLUSIONS Consistent with findings in the general population, CKD-EPI resulted in substantial declines in equation-based CKD diagnoses in a large healthcare system. Further research is needed to determine whether widespread use of CKD-EPI with current guidelines could lead to delayed needed care among younger patients or excessive referrals among older patients.

Electronic health records: a new tool to combat chronic kidney disease?

Electronic health records (EHRs) were first developed in the 1960s as clinical information systems for document storage and retrieval. Adoption of EHRs has increased in the developed world and is increasing in developing countries. Studies have shown that quality of patient care is improved among health centers with EHRs. In this article, we review the structure and function of EHRs along with an examination of its potential application in CKD care and research. Well-designed patient registries using EHRs data allow for improved aggregation of patient data for quality improvement and to facilitate clinical research. Preliminary data from the United States and other countries have demonstrated that CKD care might improve with use of EHRs-based programs. We recently developed a CKD registry derived from EHRs data at our institution and complimented the registry with other patient details from the United States Renal Data System and the Social Security Death Index. This registry allows us to conduct a EHRs-based clinical trial that examines whether empowering patients with a personal health record or patient navigators improves CKD care, along with identifying participants for other clinical trials and conducting health services research. EHRs use have shown promising results in some settings, but not in others, perhaps attributed to the differences in EHRs adoption rates and varying functionality. Thus, future studies should explore the optimal methods of using EHRs to improve CKD care and research at the individual patient level, health system and population levels.

Chronic kidney disease in an electronic health record problem list: quality of care, ESRD, and mortality.

Background: Whether chronic kidney disease (CKD) recognition in an electronic health record (EHR) problem list improves processes of care or clinical outcomes of end-stage renal disease (ESRD) and death is unclear. Methods: We identified patients who had at least 1 year of follow-up (2005-2009) in our EHR-based CKD registry (n = 25,742). CKD recognition was defined by having ICD-9 codes for CKD, diabetic kidney disease, or hypertensive kidney disease in the problem list. We calculated proportions of patients with and without CKD recognition and examined differences by demographics, clinical factors, and development of ESRD or mortality. We evaluated differences in the proportion of patients with CKD-specific laboratory results checked before and after recognition among cases and propensity-matched controls. Results: Only 11% (n = 2,735) had CKD recognition in the problem list and they were younger (68 vs. 71 years), a higher proportion were male (61 vs. 37%) and African-American (21 vs. 10%) compared to those unrecognized. CKD-specific laboratory results for patients with estimated glomerular filtration rate (eGFR) 30-59 including intact parathyroid hormone (23 vs. 6%), vitamin D (22 vs. 18%), phosphorus (29 vs. 7%), and a urine check for proteinuria (55 vs. 36%) were significantly more likely to be done among those with CKD recognition (all p < 0.05). Similar results were found for eGFR <30 except for proteinuria and in our propensity score-matched control analysis. There was no independent association of CKD recognition with ESRD or mortality. Conclusions: CKD recognition in the EHR problem list was low, but translated into more CKD-specific processes of care; however ESRD or mortality were not affected.

2009 Influenza A Infection and Acute Kidney Injury: Incidence, Risk Factors, and Complications

Background: 2009 influenza A has spread globally. Respiratory complications and renal failure have been the leading causes for hospitalization and critical illness. We describe the risk factors and complications of acute kidney injury (AKI) in patients with influenza A. Methods: Observational study of adult patients tested for influenza A. Outcome measures include AKI [AKI Network (AKIN) criteria] and mortality. Results: From August through December 2009, 17% (89/515) of hospitalized subjects were tested positive for influenza A. The incidence of AKI (AKINI–III) was 42% (37/89) in subjects with influenza A; the majority (65%, 24/37) of whom were critically ill. Risk factors for AKI included obesity, chronic kidney disease (CKD), and elevated creatine kinase. Positive influenza A status was associated with lower AKI (AKINI–III) risk compared to seronegative subjects (OR 0.5, CI 0.3–0.9). Mortality in patients with influenza A and AKI requiring dialysis was 50%. Conclusions: Obesity, CKD, and elevated creatine kinase are associated with AKI in patients with influenza A. Influenza A is not independently associated with higher incidence of AKI in hospitalized patients. AKI is an independent risk factor for mortality in patients with influenza A.