Diagnostic accuracy of urine dipsticks for detecting albuminuria in indigenous and non-indigenous children in a community setting.

Albuminuria predicts cardiovascular and end-stage kidney disease in indigenous populations. Early detection in indigenous children may identify those who could benefit from early treatment. Community-based detection of albuminuria needs to be performed using a reliable, inexpensive, and widely available test, such as a proteinuria dipstick. Dipstick accuracy for detecting albuminuria in a community setting has not been evaluated. We assessed the accuracy of Multistix 10 SG dipsticks to detect baseline albuminuria and predict for persistent albuminuria at a 2-year follow-up in a population-based cohort of Australian Aboriginal and non-Aboriginal elementary-school-aged children. Variability in the accuracy of dipsticks in subgroups of higher risk children was analyzed using the relative diagnostic odds ratio (RDOR). Using Multistix 10 SG dipsticks, index-test-positive cases were defined as >/=0.30 g/L (1+) proteinuria and index-test-negative cases as <0.30 g/L (negative or trace) proteinuria. Referent-test-positive cases were defined as spot albumin:creatinine (ACR) >/=3.4 mg/mmol, and referent-test-negative cases as ACR <3.4 mg/mmol. There were 2,266 children (55.1% Aboriginal, 51.0% boys, mean age 8.9 years) enrolled. At the 2-year follow-up, 1,432 (63.0%) children were retested (54.0% Aboriginal, 50.5% boys, mean age 10.5 years). Prevalence of baseline albuminuria was 7.3%, and persistent albuminuria was 1.5%. Dipsticks had a sensitivity of 62% and specificity of 97% at baseline. In predicting persistent albuminuria, sensitivity was 75% and specificity 93%. Accuracy did not vary with ethnicity, gender, or body mass index. Accuracy was less in younger children (4.0-7.9 years), and in those with hematuria. The performance characteristics of Multistix dipsticks make them suitable for albuminuria detection in Aboriginal and other higher-risk groups of children. More than two thirds of children detected at a single test will have transient rather than persistent albuminuria. Multistix dipsticks are particularly useful for detecting children who will have persistent albuminuria.