Early referral of patients with chronic kidney disease (CKD) to specialist nephrology care is associated with benefits that include reduced mortality at 3 months to 5 years of follow-up, reduced costs, reduced length of stay among hospitalized patients, increased quality of life, and earlier placement of preferred dialysis access. One objective of the US Office of Disease Prevention and Health Promotion’s Healthy People 2020 initiative is to increase the proportion of patients with CKD who receive care from a nephrologist a minimum of 12 months prior to initiation of renal replacement therapy.
In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) defined indications for referral to a nephrologist as part of a broader guideline for management of patients with CKD. The indications for referral included patients with CKD most likely to benefit from diagnostic work-up, close monitoring, or planning for renal replacement therapy through consultation with a nephrologist. Referral to a nephrologist for this patient population was considered a level 1B recommendation, noting it was based on moderate quality evidence. Indications for referral were acute kidney injury, progression or advanced CKD, albuminuria, urinary red cell casts, refractory hypertension, potassium abnormalities, recurrent nephrolithiasis, and hereditary kidney disease.
According to Karandeep Singh, MD, and colleagues, there are an estimated 246,500 primary care physicians currently practicing in the United States and only an estimated 9000 practicing nephrologists. Due to this mismatch in nephrologist supply and demand, referring all patients identified by the KDIGO guidelines may not be feasible.
The researchers conducted a retrospective analysis of the primary care population at Brigham and Women’s Hospital (BWH) to estimate the number of referrals that would be generated among patients with pre-existing CKD when the KDIGO guidelines were followed. They then sought to compare the estimate against the baseline referral volume to determine the feasibility of adhering to the guidelines. Results of the analysis were reported online in BMC Nephrology [doi:10.1186/s12882-017-0646-y].
There were 56,461 primary care patients seen in the primary care network at BWH from January 1 to December 31, 2013; of those, 9.9% (n=5593) had pre-existing CKD. Compared with all primary care patients, those with CKD were older, less likely to be female, and have a lower baseline estimated glomerular filtration rate (eGFR) and a greater degree of albuminuria.
The researchers evaluated 37,056 outpatient visits in 2013 among the 5593 CKD patients, identifying 2851 patients who met criteria for at least one of the 12 computable scenarios for nephrology referral (Table). Of those patients, only 21.4% (n=611/2851) were seen by a BWH nephrologist in 2013; the remaining 2240 patients were classified by the researchers as “projected new referrals” to nephrology.
Compared with those who saw a nephrologist in 2013, those in the projected new referrals group were older, more likely to be female, more likely to be white, less likely to be black, had a higher baseline eGFR and a lesser degree of albuminuria.
If the 2240 patients in the projected referrals group had been referred to a nephrologist in 2013, it would have resulted in a 38.0% (2240/5892) increase in total nephrology volume and a 67.3% (2240/3326) increase in new referral volume.
Limitations to the study cited by the researchers included the translation of the guidelines to the 12 computable criteria and the exclusion of referral guidelines and the focus on a single tertiary care center’s affiliated primary care practices.
In conclusion, the researchers said, “The main implication of our findings is that adhering to the KDIGO referral recommendations may not be feasible. We need to consider new strategies on how to deliver optimal care to CKD patients using the available workforce in the US healthcare system.”
|Diagnosis||Scenario||Criteria used to identify patients|
|Acute Kidney Injury||1||Creatinine rises by 0.3 ng/dL on most recent lab as compared to prior lab checks within last 48 hours|
|2||Creatinine has risen by at least 1.5 times within past 7 days|
|3||Estimated GFR is 50% lower as compared to the baseline eGFR, with baseline eGFR defined as the highest eGFR from the past 6 months (“abrupt sustained fall in GFR”)|
|Late Stable Chronic Kidney Disease||4||Recent eGFR and eGFR prior to 3 months ago are both <30 mL/min/1.73 m2|
|5||Recent eGFR and eGFR prior to 3 months ago are both <15 mL/min/1.73 m2|
|Albuminuria||6||Urine microalbumin/creatinine µg/mg on last two consecutive checks at least 24 hours apart|
|7||eGFR drop from ≥90 (CKD stage 1) to <89 mL/min/1.73 m2 (CKD stage 2), accompanied by a 25% drop in eGFR on most recent lab as compared to baseline, with baseline eGFR defined as the highest eGFR in the past year|
|8||eGFR drop from 60 to 89 (CKD stage 2) to <59 mL/min/1.73 m2 (CKD stage ≥3a), accompanied by a 25% drop in eGFR on most recent lab as compared to baseline, with baseline eGFR defined as highest eGFR from the past year|
|9||eGFR drop from 45 to 59 (CKD stage 3a) to <45 mL/min/1.73 m2 (CKD stage ≥3b), accompanied by a 25% drop in eGFR on most recent lab as compared to baseline, with baseline eGFR defined as highest eGFR from the past year|
|10||eGFR drop from 30 to 44 (CKD stage 3b) to <30 mL/min/1.73 m2 (CKD stage ≥4), accompanied by a 25% drop in eGFR on most recent lab as compared to baseline, with baseline eGFR defined as highest eGFR from the past year|
|11||eGFR drop from 15 to 29 (CKD stage 34) to <15 mL/min/1.73 m2 (CKD stage 5), accompanied by a 25% drop in eGFR on most recent lab as compared to baseline, with baseline eGFR defined as highest eGFR from the past year|
|12||Mean eGFR drops ≥5 mL/min/1.73 m2 per year, when the current year’s eGFR is defined by the mean eGFR for the last 365 days and the prior year’s eGFR is defined by the mean eGFR between 366 and 730 days ago|
|Abbreviations: CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate|
In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) issued recommendations for referral to a nephrologist for patients with chronic kidney disease (CKD). There are few data available on the feasibility of the recommendations.
Researchers at Brigham and Women’s Hospital (Boston) conducted a retrospective analysis of the primary care population to estimate the number of referrals that would be generated by adhering to the KDIGO recommendations among patients with pre-existing CKD.
If the recommendations had been followed in 2013, there would have been a 38.0% increase in the total nephrology patient volume and a 67.3% increase in new referral volume.