Laboratory database population surveillance to improve detection of progressive chronic kidney disease.

BACKGROUND: Some patients with chronic kidney disease are still referred late for specialist care despite the evidence that earlier detection and intervention can halt or delay progression to end-stage kidney disease (ESKD).
OBJECTIVES: To develop a population surveillance system using existing laboratory data to enable early detection of patients at high risk of ESKD by reviewing cumulative graphs of estimated glomerular filtration rate (eGFR).
METHODS: A database was developed, updated daily with data from the laboratory computer. Cumulative eGFR graphs containing up to five years of data are reviewed by clinical scientists for all primary care patients or out-patients with a low eGFR for their age. For those with a declining trend, a report containing the eGFR graph is sent to the requesting doctor. A retrospective audit was performed using historical data to assess the predictive value of the graphs.
RESULTS: In nine months, we reported 370,000 eGFR results, reviewing 12,000 eGFR graphs. On average 60 graphs per week were flagged as 'high' or 'intermediate' risk. Patients with graphs flagged as high risk had a significantly higher mortality after 3.5 years and a significantly greater chance of requiring renal replacement therapy after 4.5 years of follow-up. Five patients (7%) with graphs flagged as high risk had a sustained >25% fall in eGFR without evidence of secondary care referral. Feedback about the service from requesting clinicians was 73% positive.
CONCLUSIONS: We have developed a system for laboratory staff to review cumulative eGFR graphs for a large population and identify patients at highest risk of developing ESKD. Further research is needed to measure the impact of this service on patient outcomes.