Clinical testing patterns and cost implications of variation in the evaluation of CKD among US physicians.

Background: Clinical practice guidelines were established to improve the diagnosis and management of chronic kidney disease (CKD), but the extent, determinants, and cost implications of guideline adherence and variation in adherence have not been evaluated.
Study Design: Cross-sectional survey.
Settings & Participants: The questionnaire was sent (on paper or through the internet) to a nationally representative sample of 1,200 US primary care physicians and nephrologists.
Predictor: Provider and patient characteristics.
Outcomes & Measurements: Guideline adherence was assessed as present if physicians recommended at least 5 of 6 clinical tests prescribed by the National Kidney Foundation's Kidney Disease Outcomes and Quality Initiative guidelines for a hypothetical patient with newly identified CKD. We also assessed patterns and costs of additional nonrecommended tests for the initial clinical evaluation of CKD.
Results: Of the 301 (86 family medicine, 89 internal medicine, and 126 nephrology) eligible physicians who responded to the survey (response rate, 32%), most practiced longer than 10 years (54%), were in nonacademic practices (76%), spent greater than 80% of their time performing clinical duties (77%), and correctly estimated kidney function (73%). Overall, 35% of participants were guideline adherent. Compared with nephrologists, internal medicine and family physicians had lower odds of adherence for all recommended testing (odds ratio, 0.6; 95% confidence interval, 0.3 to 1.1; and odds ratio, 0.3; 95% confidence interval, 0.1 to 0.6, respectively). Participants practicing longer than 10 years had lower odds of ordering all recommended testing compared with participants practicing fewer than 10 years (odds ratio, 0.5; 95% confidence interval, 0.3 to 0.9). Eighty-five percent of participants recommended additional tests, which resulted in a 23% increased total per-patient cost of the clinical evaluation.
Limitations: Recommendations for a hypothetical case scenario may differ from those of actual patients.
Conclusions: Adherence to recommended clinical testing for the diagnosis and management of CKD was poor, and additional testing was associated with substantially increased cost of the clinical evaluation. Improved clarity, dissemination, and uptake of existing guidelines are needed to improve quality and decrease costs of care for patients with CKD.