Urine dipstick testsBMJ 2009; 338 doi: https://doi.org/10.1136/sbmj.b260 (Published 01 February 2009) Cite this as: BMJ 2009;338:b260
- Kesavapillai Subramonian, consultant urological surgeon1,
- Hannah Frances MacDonald, fourth year medical student2,
- Ravi Kiran Vijapurapu, fourth year medical student 2,
- Sohraab Yadav, fourth year medical student2
- 1Queen Elizabeth Hospital, Birmingham, West Midlands
- 2University of Birmingham
Urine dipstick testing is cheap, easy, readily accessible, and gives instant results. It can also act as a screening tool for many diseases, making it invaluable in clinical practice. The urine dipstick test is a critical part of the physical examination of any new case in both primary and secondary care, and can be competently carried out and interpreted by anyone.
The sample should be mid-stream, and collected into a sterile container. Check the expiry date and storage conditions of the urine dipstick test. The stick must be quickly dipped into the urine, and then laid to dry on a clean surface. It is important to take the reading at the correct time interval (usually specified on the container) to get an accurate result. However, as with any investigation, the simple urine dipstick test has its limitations.
Proteinuria is the presence of protein in the urine, and none should be detected in a healthy person. Less than 1 g/l protein or occasional readings greater than 1 g/l may represent a cardiac cause, or be for a non-specific reasons, such as inflammation or smoking. A persistent reading (two or more positive tests spaced by at least two weeks) of more than 1 g/l is usually of renal origin. The sensitivity of the standard urine dipstick tests for identifying low levels of protein is 80.7%.1 Substantial proteinuria (3 g/l) is detected with a sensitivity and specificity of 96% and 87% respectively.2
However, UK guidelines from the National Institute for Health and Clinical Excellence (NICE) suggest that the urine dipstick test should only be used to identify proteinuria if microalbuminuria can be measured.3 Microalbuminuria occurs when small amounts of albumin pass into the urine and can be an indicator of early renal …