Nephrology Comanagement and the Quality of Antibiotic Prescribing in Primary Care for Patients With Chronic Kidney Disease: A Retrospective Cross-sectional Study

A Retrospective Cross-Sectional Study

Justin X.G. Zhu; Danielle M. Nash; Eric McArthur; Alexandra Farag; Amit X. Garg; Arsh K. Jain


Nephrol Dial Transplant. 2019;34(4):642-649. 

In This Article

Abstract and Introduction


Background: In primary care, patients with chronic kidney disease (CKD) are frequently prescribed excessive doses of antibiotics relative to their kidney function. We examined whether nephrology comanagement is associated with improved prescribing in primary care.

Methods: In a retrospective propensity score–matched cross-sectional study, we studied the appropriateness of antibiotic prescriptions by primary care physicians to Ontarians ≥66 years of age with CKD Stages 4 and 5 (estimated glomerular filtration rate <30 mL/min/1.73 m2 not receiving dialysis) from 1 April 2003 to 31 March 2014. Comanagement was defined as having at least one outpatient visit with a nephrologist within the year prior to antibiotic prescription date. We compared the rate of appropriately dosed antibiotics in primary care between 3937 patients who were comanaged by a nephrologist and 3937 patients who were not.

Results: Only 1184 (30%) of 3937 noncomanaged patients had appropriately dosed antibiotic prescriptions prescribed by a primary care physician. Nephrology comanagement was associated with an increased likelihood that an appropriately dosed prescription was prescribed by a primary care physician; however, the magnitude of the effect was modest [1342/3937 (34%); odds ratio 1.20 (95% confidence interval 1.09–1.32); P < 0.001].

Conclusion: The majority of antibiotics prescribed by primary care physicians are inappropriately dosed in CKD patients, whether or not a nephrologist is comanaging the patient. Nephrologists have an opportunity to increase awareness of appropriate dosing of medications in primary care through the patients they comanage.


Patients with chronic kidney disease (CKD) have higher risks of mortality and morbidity than the general population.[1,2] While most patients with early CKD (i.e. Stages 1–3) are solely managed by primary care physicians, patients with more advanced CKD (i.e. Stages 4 and 5) are frequently comanaged with nephrologists. The addition of nephrologists to advanced CKD care improves guideline adherence and has been associated with better outcomes, including lower mortality, decreased progression of disease and fewer hospitalizations.[3–9]

Patients with CKD are at high risk of receiving medications inappropriately dosed relative to their kidney function.[10] Rates of inappropriately dosed medications have ranged from 30% to >50%.[11–13] In a prior study we found that 64% of outpatient antibiotic prescriptions were dosed inappropriately in nondialysis patients with Stage 4 or 5 CKD.[14]

In the face of the poor quality of antibiotic prescribing in patients with advanced CKD, the nephrology consultation note represents an opportunity to provide education to the primary care physician to increase awareness of the need to dose-adjust medications for a given patient's level of kidney function. We conducted this study to determine if the quality of antibiotic prescribing by primary care physicians in patients with advanced CKD was influenced by nephrology comanagement. We hypothesized that nephrology comanagement would positively impact primary care physicians' prescribing practices and have an association with appropriately dosed prescriptions.