Twelve studies with a total of 8,837 participants were included in the review. All the included studies were of quality level 1 to 4. Two studies classed as level 5 were excluded.
All of the included studies were assigned quality levels between 1 and 4. Half of the included studies were of quality level 1 (independent, blind comparisons of signs and symptoms with urine culture, in 200 or more consecutive participants with suspected UTI).
Precision of signs and symptoms.
One study quantified agreement on clinical history and examination between the examining physician and study nurse: agreement was fair to good (measured by the kappa statistic) between 200 physician/nurse pairs.
Diagnostic accuracy of signs and symptoms in febrile infants under 2 years.
The findings considered most useful for identifying infants with a UTI were previous history of UTI (positive LR 2.3 and 2.9; 2 studies), temperature higher than 40 degrees C (positive LR 3.2 and 3.3; 2 studies), supra-public tenderness (positive LR 4.4 , 95% confidence interval, CI: 1.6, 12.4; 1 study) and lack of circumcision in male infants (positive LR 2.8, 95% CI: 1.9, 4.3; 6 studies). Presence of circumcision in male infants was the only finding with a negative LR below 0.5 (summary negative LR 0.33, 95% CI: 0.18, 0.63; 6 studies). Combinations of findings were considered more useful than individual signs and symptoms for identifying individuals with UTI: for a temperature above 39 degrees C for more than 48 hours and the absence of another potential source of fever, the positive LR for all other signs and symptoms present was 4.0 (95% CI: 1.2, 13.0), whereas for a temperature below 39 degrees C and the presence of another source of fever, the positive LR was 0.37 (95% CI: 0.16, 0.85); these observations were based on data from 2 separate individual studies and no definition of 'all other signs and symptoms' was provided.
Diagnostic accuracy of signs and symptoms in verbal children.
Abdominal pain (positive LR 6.3, 95% CI: 2.5, 16.0; 1 study), back pain (positive LR 3.6, 95% CI: 2.1, 6.1; 1 study), dysuria and/or frequency (positive LR range: 2.2 to 2.8; 3 studies) and new-onset urinary incontinence (positive LR 4.6, 95% CI: 2.8, 7.6; 1 study) increased the likelihood of UTI.
A diagnostic algorithm, in the form of a flow chart, was presented for verbal children older than 24 months with urinary or abdominal symptoms.