The validity of urine examination for urinary tract infections in daily practice

Abstract

For urinary tract infections (UTI), diagnostic testing appears to be reliable and simple to perform. This particularly seems to hold true for test strips. In studies the validity of several urine tests proved to be high. These studies were, however, performed under optimal and standardized conditions. Their results therefore do not reflect daily practice. In this study the validity of urine tests for UTI is deterined under daily practice conditions, without the use of a protocol. The results show a validity considerably lower than under optimal conditions. Specificity in particular was lower, even for simple tests like the nitrite reaction. Under daily practice conditions, UTI can neither be confirmed nor excluded sufficiently on the outcome of a urinary sediment or test strip.

Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study

“…Previous studies in primary care have either had limited power 19 or not assessed the independent value of dipstick results using multivariate analysis. 11,13,14,18 These findings demonstrate the importance of multivariate analysis and contradict previous findings about protein, 18 which does not independently predict UTI. Dipsticks have the potential to target treatment and to have lower costs depending on the precise strategy used.…”

“…[10][11][12][13] Summary data are available of studies that assessed nitrite and leucocyte esterase separately, but primary data are needed to assess the independent predictive value of all dipstick results.…”

“…13,15,16 Studies from primary care have a range of one or more limitations: 9,11,[15][16][17][18][19] they have not assessed the independent value of dipstick results and symptoms (hence potentially overcomplicating clinical decision rules); they have not used the range of dipstick variables (most include nitrite and leucocyte but not blood); they have failed to develop and then test algorithms in separate samples (the study by McIsaac et al 19 being the exception); and/or they have low power. Only the most recent dipstick studies 17,19 have used the recent more rigorous laboratory guidelines for diagnosis.…”

Validating the prediction of lower urinary tract infection in primary care: sensitivity and specificity of urinary dipsticks and clinical scores in women

“…7 Clinicians commonly use dipsticks to rule out infection, and they are the most widely used simple near-patient test in primary care. [8][9][10][11] Although summary data are available for studies that assessed nitrite and leucocyte esterase separately, primary data are needed to assess the independent predictive value of all dipstick results. 12 The evidence base for dipstick use in primary care is poor, due to the paucity of studies and 'spectrum bias'.…”

“…12 The evidence base for dipstick use in primary care is poor, due to the paucity of studies and 'spectrum bias'. 6,11,13 Studies from primary care have a range of one or more limitations:…”