A national audit of estimated glomerular filtration rate and proteinuria reporting in the UK.

BACKGROUND: Within the UK there has been a rapid move to include the reporting of estimated glomerular filtration rate (eGFR) values to identify patients with chronic kidney disease (CKD). Guidance has also changed since its original introduction. This national audit aimed to establish how eGFR is reported by laboratories within the UK.
METHODS: A questionnaire was sent to 164 UK National Health Service laboratories, which included questions on the patient groups who had eGFR reported, the eGFR thresholds used, adjustments made for ethnicity and the means of identifying proteinuria. The audit standards used were based on the 2008 National Institute for Health and Clinical Excellencec (NICE) CKD guidance.
RESULTS: One hundred and thirty-one of the 164 laboratories (80%) responded. Forty-six percent reported eGFR on all adult requests while 36% limited use to general practitioners. Twenty-one percent did not issue eGFR to any inpatient. Sixty-two percent and 30% of laboratories had an upper reporting limit of ≥90 and ≥60 mL/min/1.73 m(2), respectively; the remainder having higher thresholds. Sixty percent cited an ethnicity 'correction factor' on the report, 59% in a guideline but 28% in neither. An albumin:creatinine ratio was used by 63% to detect non-diabetic proteinuria, while 37% exclusively used a protein:creatinine ratio.
CONCLUSIONS: There has been rapid implementation of eGFR reporting in the UK since 2006. However, there is considerable variation in the way it is reported, with few laboratories currently exactly matching existing NICE recommendations. A reassessment of biochemical CKD assessment by most laboratories following a reiteration and clarification of current recommendations seems warranted.