Screening for Chronic Kidney Disease (CKD) in a high risk population using a Point of Care Instrument for creatinine measurement: A community based study (The Bellville South Africa Study)

[摘要] ENGLISH ABSTRACT : Chronic kidney disease (CKD) is described as abnormal kidney function in which one third islost over a period of 3 months and is a global epidemic with a particularly concentratedincidence within developing countries, such as Sub-Sahara Africa (SSA). Health facilities inSSA are limited due to lack of funding and a dearth in disease and medical knowledge. Thiscoupled with the high incidence of both communicable and non-communicable diseasesmakes for an ideal environment for the implementation of Point-of-Care Testing (POCT),defined as an analytical test that is performed near the patient, delivering results in real timewithout the need for a conventional laboratory. CKD POCT involves the measurement ofcreatinine in capillary whole blood samples in order to determine the estimated glomerularfiltration rate (eGFR) of patients in order to stage their CKD status from stage 1-6.This study aimed to bridge the gap in knowledge with regard to cut-offs of creatinine levelsand eGFR values when screening a mixed ancestry populations. Currently there is onlydocumented and standardized cut-offs for Caucasian and African American populations. Thisstudy looked at the African mixed ancestry population and acts as a starting point forstandardizing POCT cut-offs for other international mixed ancestry populations.103 participants were recruited from the Bellville South community, Cape Town, South Africa. Thestudy was a comparative study that was designed to evaluate the Nova Statsensor® point of careinstrument for the measurement of creatinine for the detection of CKD in adult mixed ancestrysubjects from the Bellville South Community in South Africa. Secondary objectives included (1)the prevalence of CKD based on the results of the instrument, and (2) the correlation between theNova Statsensor®, and the central laboratory creatinine values (IDMS traceable). Ancillaryobjectives of the study were to evaluate the technical quality of POC testing for creatinine in acommunity setting, as well as the evaluation of the cost implications when introducing this form ofPOCT into a primary care setting.The study found that the Nova Statsensor® in this study had a sensitivity of 66.7% and aspecificity of 100%, displaying excellent diagnostic accuracy. It was found that the devicedisplayed negative proportional bias which may lead to future CKD patients beingmisdiagnosed as healthy within screening programmes. The prevalence was found to be 2.9%within this mixed ancestry population.The device was user friendly and requires a small sample volume, however it is costly toimplement.The laboratory evaluation study found that the Nova Statsensor® creatinine meter produced adirect creatinine concentration comparison that was less than expected, possibly due to creatininelevels depending on several factors which include muscle mass, obesity, gender, and age andhaving a wide reference interval. Thus highlighting the importance of the use of the equations tocalculate eGFR in CKD screening in order to obtain the CKD staging results which displayed bettercorrelation to the reference method, compared to creatinine measurement alone. The device wascomparable to the reference method when performance was measured based on CKD stagingthrough the calculation of the MDRD equation.

[发布机构] Stellenbosch University