Predicting mortality and uptake of renal replacement therapy in patients with stage 4 chronic kidney disease

Novel strategies are required to efficiently manage the increasing number of patients diagnosed with chronic kidney disease (CKD). We sought to identify factors predicting outcome in patients with stage 4 CKD and to determine whether low-risk patients could be managed in primary care.

We performed a two-centre, retrospective cohort study including 396 patients with stage 4 CKD referred to nephrology clinics from 1998 to 2002. We utilized electronic databases to determine the incidence of renal replacement therapy (RRT) and mortality and the rate of deterioration in estimated glomerular filtration rate (eGFR) to the year end 2005.

This was an elderly cohort, with 71.7% of patients aged > or =65 years. The risk of surviving to require dialysis fell with increasing age (HR 0.44; 95% CI: 0.23-0.84 for those >74 years verses those <65 years), in part due to the slower rate of decline in renal function in older patients (median fall in eGFR was -2.25, -1.38 and -0.86 ml/ min/1.73 m(2)/year in those aged <65 years, 65-74 years and >74 years, respectively, P < 0.0001). Additional independent risk factors predicting RRT included: high baseline proteinuria (HR 6.26; 95% CI: 2.74-14.23 for >3 g/24 h versus <0.3 g/24 h), greater early decline in renal function (HR 3.86; 95% CI: 2.34-6.38 for > or =4 ml/min/1.73 m(2)/year versus <4 ml/min/1.73 m(2)/year), low baseline eGFR (HR 2.92; 95% CI: 1.61-5.30 for 15-19 versus 25-29 ml/min/1.73 m(2)) and low haemoglobin (HR 3.16; 95% CI: 1.64-6.08 for <10 versus >12 g/dl). The 98 (24.7%) patients discharged to primary care had more stable renal function than those remaining under nephrology care (median change in eGFR of +0.20 versus -1.88 ml/ min/1.73 m(2)/year, P = 0.0001).

Most patients with stage 4 CKD, in particular the elderly, die without commencing RRT. Patients at low risk of progression can be identified and discharged safely to primary care with an active management plan.