Adherence to K/DOQI Bone Metabolism Guidelines

Objective: Guidelines for the treatment of patients with chronic kidney disease recommend laboratory testing of markers of bone metabolism, including intact parathyroid hormone, calcium, and phosphorus. The authors sought to evaluate the concordance of contemporary clinical practice with treatment recommendations. Trends were evaluated (2002 to 2005) in testing for bone metabolism in patients with chronic kidney disease, and the relation between bone metabolism markers, severity of chronic kidney disease, and cardiovascular hospitalizations were examined. Design: Retrospective cohort. Setting: Large United States health-maintenance organization. Patients: Chronic kidney disease. Results: Little variation was found in testing rates over time. Testing frequency was positively correlated with severity of kidney disease, referral to nephrology, and test type (annual testing was most likely for intact parathyroid hormone, and least likely for calcium). Patients with higher intact parathyroid hormone values had a greater risk of cardiovascular-related hospitalization; after adjusting for potential confounders, those with an intact parathyroid hormone value of 200 and greater had a relative risk of 2.16 (95% confidence interval, 1.09 to 4.29). Conclusions: This study supports the hypothesized association between disorders of bone metabolism and cardiovascular disease, but it does not address whether increased testing for disorders of bone metabolism will improve outcomes for patients with chronic kidney disease. Nor does our analysis imply that controlling parathyroid hormone will prevent cardiovascular hospitalizations. Future studies should more fully explore those critical clinical questions. (C) 2009 by the National Kidney Foundation, Inc. All rights reserved.