Clinical trial NCT02433002: Accuracy of Glomerular Filtration Rate (GFR) Estimation Using Creatinine and Cystatin C and Albuminuria
Official title: Accuracy of Glomerular Filtration Rate Estimation Using Creatinine & Cystatin C & Albuminuria for Monitoring Disease Progression in Patients With Stage 3 Chronic Kidney Disease: Prospective Longitudinal Study in a Multi-ethnic Population
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Chronic Kidney Diseases
Keywords: eGFR
CKD
Cystatin
Creatinine
Albuminuria
Lead sponsor: University of Birmingham
Sponsor class: OTHER
Collaborators: name: East Kent Hospitals University NHS Foundation Trust
name: National Institute for Health Research, United Kingdom
First posted: 2015-05-04
Enrollment: 1249
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Adults with stage 3 CKD.

Brief summary: The eGFR-C study will assess the accuracy of current and alternative tests of kidney function against a reference test in people with moderate (stage 3) chronic kidney disease (CKD).

Detailed description: The eGFR-C study will assess the accuracy of current and alternative tests of kidney function against a reference test in people with moderate (stage 3) CKD. Participants will be recruited from hospital clinics and General Practitioner (GP) practices at six major United Kingdom (UK) centres.

The best measure of kidney function is accepted to be the glomerular filtration rate (GFR), which measures the ability of the kidney to filter blood and is widely used in clinical practice. A low GFR suggests poor kidney function. An estimate of GFR can be obtained from a simple blood test.

Participants will undergo reference GFR testing at study entry with a second follow-up reference test three years later. The reference test involves injecting a small amount of iohexol into a vein and taking blood samples over the next 4 hours to see how quickly the iohexol disappears from the blood stream as a result of glomerular filtration. The rate at which iohexol disappears is equivalent to the level of kidney function. Blood tests for monitoring kidney function, including testing for creatinine and cystatin C, and measurement of urinary albumin will be done every six months during the study period.

Iohexol measured GFR will be accepted as the reference ('gold standard') measure of kidney function against which each GFR-estimating equations will be compared. The alternative estimated measures of GFR, derived from measuring substances (creatinine and cystatin C) in the blood, will be compared against the reference test. An important outcome is how much the reference test changes over the three years of the study, and how well the surrogate measures reflect this change.

The investigators will also collect accurate test cost data for subsequent cost-effectiveness analysis (e.g. do the relative costs of the tests justify any change in practice due to improved performance of one test compared to another?).

Eligibility criteria: Inclusion Criteria:

* Patients with stage 3 CKD (GFR 30-59 mL/min/1.73 m2) as defined internationally, diagnosed using MDRD/CKDEPI eGFR (at least two consecutive test results in this range at least 90 days apart, with the most recent test in the last 12 months)
* Aged 18 years or over
* Written informed consent

Exclusion Criteria:

* History of untoward reactions to iodinated contrast media or allergy to topical iodine
* Episode of acute kidney injury in previous 6 months (as defined by the Acute Kidney Injury Network criteria)
* Amputation of whole or part-limb
* Pregnant or breastfeeding
* Known current alcohol or drug abuse
* Kidney transplant recipient
* Any condition with an expected survival of less than study duration
* Inability to comply with study schedule and follow-up
* Inability to provide informed consent e.g. due to cognitive impairment

Primary outcomes:
measure: Percentage of estimated Glomerular Filtration Rate values within 30% of 'true' Glomerular Filtration Rate
timeFrame: Baseline
Secondary outcomes:
Other outcomes:
Locations:
city: Derby
country: United Kingdom
facility: Derby Hospitals NHS Foundation Trust (Royal Derby Hospital)
state: Derbyshire
city: London
country: United Kingdom
facility: King's College Hospital NHS Foundation Trust
state: Greater London
city: Salford
country: United Kingdom
facility: Salford Royal NHS Foundation Trust (Salford Royal Hospital)
state: Greater Manchester
city: Canterbury
country: United Kingdom
facility: East Kent Hospitals NHS Trust (Kent & Canterbury Hospital)
state: Kent
city: Leicester
country: United Kingdom
facility: University Hospitals of Leicester NHS Trust (Leicester General Hospital)
state: Leicestershire
city: Birmingham
country: United Kingdom
facility: University Hospital Birmingham NHS Trust (Queen Elizabeth Hospital Birmingham)
state: West Midlands
Study officials:
affiliation: East Kent Hospitals University NHS Foundation Trust
name: Edmund Lamb, PhD, FRCPath
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lamb EJ, Brettell EA, Cockwell P, Dalton N, Deeks JJ, Harris K, Higgins T, Kalra PA, Khunti K, Loud F, Ottridge RS, Sharpe CC, Sitch AJ, Stevens PE, Sutton AJ, Taal MW; eGFR-C study group. The eGFR-C study: accuracy of glomerular filtration rate (GFR) estimation using creatinine and cystatin C and albuminuria for monitoring disease progression in patients with stage 3 chronic kidney disease--prospective longitudinal study in a multiethnic population. BMC Nephrol. 2014 Jan 14;15:13. doi: 10.1186/1471-2369-15-13.
citation: Rowe C, Sitch AJ, Barratt J, Brettell EA, Cockwell P, Dalton RN, Deeks JJ, Eaglestone G, Pellatt-Higgins T, Kalra PA, Khunti K, Loud FC, Morris FS, Ottridge RS, Stevens PE, Sharpe CC, Sutton AJ, Taal MW, Lamb EJ; eGFR-C Study Group. Biological variation of measured and estimated glomerular filtration rate in patients with chronic kidney disease. Kidney Int. 2019 Aug;96(2):429-435. doi: 10.1016/j.kint.2019.02.021. Epub 2019 Mar 7.