The aim of the study is to investigate the baseline epidemiological and clinical profiles of patients at first referral to an outpatient nephrology clinic.
Case studies and methods
Cross-sectional study of all outpatients newly referred to a nephrology clinic over 12 months. A total of 282 patients was examined (64.9% males), mean age 64.5±17.8 years (13-95 years, modal value 72) ( Fig. 1 ).
Sixty-six percent of patients were referred by a primary care physician, 27% by an internist (diabetologist) and 7% for nephrologic follow-up after hospitalization (Fig. 2). Referral indications included renal impairment (60%), abnormalities of urinalysis (26%), and morphological alterations (16%) (Fig. 3). Serum creatinine and urinalysis had been determined prior to referral in 252/282 and 142/282 patients, respectively. Seventy-two % of patients had hypertension, 39% heart disease, 31% arterial-vascular disease, 27% diabetes, 32% urologic disease and 23% malignancies (mean number of comorbidities 3.2±2.0) (Fig. 4). Serum creatinine ranged 0.43-4.91 mg/dl, mean 1.48±0.68, and the eGFR (MDRD simplified formula) ranged 9.6-162.0, mean 57.2±28 ml/min/1.73m²; CKD stage 1: 12.7%; stage 2: 23.8%; stage 3a: 24.2 %, stage 3b 25.8%, and CKD stages 4&5: 13.5% (Fig. 5). Fourty-two%of patients, classified as CKD stage 2 or 3a(GFR <90->45 ml/min/1.73m2), had a normal renal function after adjustement of eGFR to their age, assuming a reduction of 1 ml/min/1.73m2 per year over the age of 40 years. Abdominal ultrasounds had been performed on 186/282 patients. Renal dimensions were measured only in 43%. Thirty % had abnormalities of echogenicity, 36.6% cysts, 7.5% stones, 5.4% focal space-occupying lesions and 5.4% urinary tract dilation.
The majority of patients are referred to a nephrology clinic by their doctor, due to impaired eGFR, often without urinalysis. They are elderly patients, with a high incidence of arterial hypertension and cardiovascular and metabolic comorbidities. Possibly, many aged patients are misclassified for CKD stage, if eGFR is not adjusted to age.