Estimated GFR reporting is not sufficient to allow detection of chronic kidney disease in an Italian regional hospital

Chronic kidney disease (CKD) is an emerging worldwide problem. The lack of attention paid to kidney disease is well known and has been described in previous publications. However, little is known about the magnitude of the problem in highly specialized hospitals where serum creatinine values are used to estimate GFR values.

Although CKD was common in this patient population at a large inpatient regional hospital, the low rates of CKD detection emphasize the primary role nephrologists must play in continued medical education, and the need for ongoing efforts to train physicians (particularly primary care providers) regarding eGFR interpretation and systematic screening for CKD in high-risk patients (i.e., the elderly, diabetics, hypertensives, and patients with CV disease).

We performed a cross-sectional evaluation of hospitalized adult patients who were admitted to the medical or surgical department of Santa Maria della Misericordia Hospital in 2007. Information regarding admissions was derived from a database. Our goal was to assess the prevalence of CKD (defined as an estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m2) and detection of CKD using diagnostic codes (Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]). To reduce the impact of acute renal failure on the study, the last eGFR obtained during hospitalization was the value used for analysis, and intensive care and nephrology unit admissions were excluded. We also excluded patients who had ICD-9-CM codes for renal replacement therapy, acute renal failure, and contrast administration listed as discharge diagnoses.

Of the 18,412 patients included in the study, 4,748 (25.8%) had reduced eGFRs, falling into the category of Kidney Disease Outcomes Quality Initiative (KDOQI) stage 3 (or higher) CKD. However, the diagnosis of CKD was only reported in 19% of these patients (904/4,748). It is therefore evident that there was a "gray area" corresponding to stage 3 CKD (eGFR 30-59 ml/min), in which most CKD diagnoses are missed. The ICD-9 code sensitivity for detecting CKD was significantly higher in patients with diabetes, hypertension, and cardiovascular disease (26.8%, 22.2%, and 23.7%, respectively) than in subjects without diabetes, hypertension, or cardiovascular disease (p < 0.001), but these values are low when the widely described relationship between such comorbidities and CKD is considered.