Chronic kidney disease prevalence in Rivas, Nicaragua: use of a field device for creatinine measurement

Objective: An epidemic of chronic kidney disease (CKD) has been identified in Pacific coastal regions of Central America, and screening in the field in these low income countries remains logistically problematic. We tested the performance characteristics of a point of care creatinine analyzer compared to standardized serum creatinine measurements.

Methods: Measurements were conducted in 100 persons from a local health center (n=34) and hospital (n=66) in Rivas, Nicaragua using both a point-of-care analyzer (StatSensor Xpress, Nova Biomedical) and serum creatinine by Jaffe kinetic method with a Roche Cobas Integra 400 analyzer. Percent coefficient of variation, sensitivity and specificity of the StatSensor Xpress were determined.

Results: The average coefficient of variation (CV) was 1.28% for the serum creatinine and CV for the StatSensor Xpress analyzer was 6.8%. The median intra-individual creatinine results obtained with the StatSensor Xpress device were 0.32 mg/dL higher than those by serum creatinine by Jaffe kinetic method. The sensitivity and specificity of the StatSensor Xpress device for identifying subjects with abnormal creatinine (defined as >1.2 mg/dL) was 100% and 79%, respectively.

Conclusions: Point of care testing for creatinine demonstrated acceptable repeatability, excellent sensitivity (100%) and modest specificity (79%). Using the point of care testing will allow for generalized screening in the field in low income countries; however, confirmation for elevated levels >1.2 mg/dL will require a second laboratory test confirmation.