Diagnostic accuracy of urine dipsticks for detecting albuminuria in indigenous and non-indigenous children in a community setting
- 117 Downloads
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.
KeywordsProteinuria Albuminuria Diagnostic test ACR Aboriginal Children
We thank the Aboriginal communities, Aboriginal Medical Services, schools, Aboriginal Education Assistants, Aboriginal Area Health Workers, all families, and The Children’s Hospital nursing staff who participated in this study. We also thank Bayer for the loan of the Clinitek 50 urinalysis machine, The Far West Population Health Division, and Maari Ma Health Aboriginal Corporation for their assistance in visiting the remote communities. We acknowledge the financial support provided by the National Health and Medical Research Centre for Clinical Excellence in Renal Medicine, the Financial Markets Foundation for Children, and the National Health and Medical Research Council for the first author’s Training Scholarship in Indigenous Health Research.
Role of the funding source
Funding bodies had no role in the study design, data collection, data analysis, data interpretation, or writing of the report.
Conflict of interest statement
There were no competing interests identified in the data collection or writing of this manuscript.
- 2.US Renal Data System (2006) Annual data report. http://www.usrds.org. Accessed 22 May 2008
- 3.Kidney Health Australia (2007) Fact sheet, 16 Feb 2007. http://www.kidney.org.au. Accessed 22 May 2008
- 4.ANZDATA 29th Annual Report. http://www.anzdata.org.au. Accessed 22 May 2008
- 8.Hoy WE, Kondalsamy-Chennakesavan S, McDonald S, Wang Z (2006) Renal disease, the metabolic syndrome and cardiovascular disease. Ethn Dis 16(Suppl 2):46–51Google Scholar
- 9.Nelson RG, Meyer TW, Myers BD, Bennett PH (1997) Course of renal disease in Pima Indians with non-insulin dependent diabetes mellitus. Kidney Int 52(Suppl 63):S45–S48Google Scholar
- 13.Gansevoort RT, Verhave JC, Hillege HL, Burgerhof JG, Bakker SJ, de Zeeuw D, de Jong PE, for the PREVEND Study Group (2005) The validity of screening based on spot morning urine samples to detect subjects with micro-albuminuria in the general population. Kidney Int Suppl 94:S28–S35PubMedCrossRefGoogle Scholar
- 15.Australian Bureau of Statistics: Population Information – Distribution. Canberra (Australia). Commonwealth of AustraliaGoogle Scholar
- 16.National Health and Medical Research Council. Values and Ethics: Guidelines for ethical conduct in Aboriginal and Torres Strait Islander health research. Canberra (Australia). Commonwealth of AustraliaGoogle Scholar
- 17.National Kidney Foundation (2002) K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification and stratification. www.kidney.org/professionals/kdoqi/guidelines_ckd/p5_lab_g5.htm
- 19.Shephard MDS: Analytical performance criteria for point-of-care testing instruments. In: Standards for point of care testing in general practice. Incorporating POCT guidelines. Canberra: Australian Government Department of Health and Ageing, pp 101–140Google Scholar
- 22.Greenacre P (1997) Height and Weight Standard Deviation Score Calculator 1997. The Children’s Hospital at Westmead, New South Wales, Australia, p 2145Google Scholar
- 30.Ruggenenti P, Gaspari F, Perna A, Remuzzi G (1998) Cross-sectional longitudinal study of spot morning urine protein:creatinine ratio, 24 hour urine protein excretion rate, glomerular filtration rate, and end-stage renal failure in chronic renal disease in patients without diabetes. BMJ 316:504–509PubMedGoogle Scholar