Non-traditional risk factors predict coronary calcification in chronic kidney disease in a population-based cohort.

The increased burden of cardiovascular disease in chronic kidney disease cannot be explained by traditional risk factors alone. Here, we evaluated the impact of non-traditional factors on the association of chronic kidney disease with coronary artery calcification using logistic regression among 2672 Dallas Heart Study patients of whom 220 had chronic kidney disease. The prevalence of coronary calcification significantly increased across all chronic kidney disease stages and this remained independently associated with coronary calcification after adjusting for traditional factors. The calcium x phosphorus product, homocysteine, and osteoprotegerin each diminished the magnitude of association between kidney disease and coronary calcification. After adjustment for these, the association between kidney disease and coronary calcification was no longer significant with the effects most prominent in the stages 3-5 subgroup. Our study has identified three non-traditional independent predictors of coronary calcification that diminished the association between chronic kidney disease and coronary calcification. These factors may represent novel mechanistic links warranting further investigation.

Associations between CMS's Clinical Performance Measures project benchmarks, profit structure, and mortality in dialysis units.

Prior studies observing greater mortality in for-profit dialysis units have not captured information about benchmarks of care. This study was undertaken to examine the association between profit status and mortality while achieving benchmarks. Utilizing data from the US Renal Data System and the Centers for Medicare & Medicaid Services' end-stage renal disease (ESRD) Clinical Performance Measures project, hemodialysis units were categorized as for-profit or not-for-profit. Associations with mortality at 1 year were estimated using Cox regression. Two thousand six hundred and eighty-five dialysis units (31,515 patients) were designated as for-profit and 1018 (15,085 patients) as not-for-profit. Patients in for-profit facilities were more likely to be older, black, female, diabetic, and have higher urea reduction ratio (URR), hematocrit, serum albumin, and transferrin saturation. Patients (19.4 and 18.6%) in for-profit and not-for-profit units died, respectively. In unadjusted analyses, profit status was not associated with mortality (hazard ratio (HR)=1.04, P=0.09). When added to models with profit status, the following resulted in a significant association between profit status (for-profit vs not-for-profit) and increasing mortality risk: URR, hematocrit, albumin, and ESRD Network. In adjusted models, patients in for-profit facilities had a greater death risk (HR 1.09, P=0.004). More patients in for-profit units met clinical benchmarks. Survival among patients in for-profit units was similar to not-for-profit units. This suggests that in the contemporary era, interventions in for-profit dialysis units have not impaired their ability to deliver performance benchmarks and do not affect survival.

The predictive value of self-report scales compared with physician diagnosis of depression in hemodialysis patients.

The prevalence of depression in end-stage renal disease (ESRD) patients on hemodialysis has not been definitively determined. We examined the prevalence of depression and the sensitivity, specificity, positive, and negative likelihood ratios (+LR and -LR) of self-report scales using the physician-administered Structured Clinical Interview for Depression (SCID) as the comparison. Ninety-eight consecutive patients completed the Beck Depression Inventory (BDI) and the Center for Epidemiological Study of Depression (CESD) scales. A physician blinded to BDI and CESD scores administered the SCID. Receiver/responder operating characteristic curves determined the best BDI and CESD cutoffs for depression. Depressed patients had more co-morbidities and lower quality of life, P<0.05. The prevalence of depression by SCID was 26.5% and of major depression was 17.3%. The CESD cutoff with the best diagnostic accuracy was 18, with sensitivity 69% (95% confidence interval (CI) (51%, 87%)), specificity 83% (95% CI (74%, 92%)), positive predictive value (PPV) 60%, negative predictive value (NPV) 88%, +LR 4.14, and -LR 0.37. The best BDI cutoff was 14, with sensitivity 62% (95% CI (43%, 81%)), specificity 81% (95% CI (72%, 90%)), PPV 53%, NPV 85%, +LR 3.26, and -LR 0.47. Self-report scales have high +LR but low -LR for diagnosis of depression. When used for screening, the threshold for depression should be higher for ESRD compared with non-ESRD patients. Identifying depression using physician interview is important, given the low -LR of self-report scales.