Rationalising the use of investigation for urinary tract infections:
Analysis of 700 patients and proposal for a diagnostic algorithm.
Abstract
Aims: To evaluate the diagnostic yield of investigations performed on
patients with a history of urinary tract infections (UTI). Methods: A
retrospective review was conducted on patients who underwent cystoscopy
and imaging for a history of UTI between 2014-2019 in a single UK
teaching hospital. Data was collected on demographics, cystoscopy and
radiological findings requiring further management. The cohort was
stratified by age, gender, and a confirmed history of recurrent UTI
(rUTI). The subsequent algorithm was re-tested in a second cohort to
validate its use. Results: 700 patients were included in the primary
analysis, 427 female and 273 males. 331 meet the criteria of rUTI. The
median age was 64y(18-97). Imaging abnormalities were equally frequent
in males 6.3%(15/241) and females 8%(30/380) and the majority noted in
patients aged ≥55y, 30/45(66.7%). Amongst those who did not meet the
definition of rUTI, abnormal imaging was identified in 5-7% regardless
of age group and gender. Cystoscopy abnormalities (n=24) were twice more
likely in males, 5.5%(15/273) than females, 2%(9/427). 88%(21/24)
were identified in patients ≥55y. There were no positive findings in
women <55y. Applying baseline imaging but confining cystoscopy
to those aged ≥55y and men with a confirmed history of rUTI would have
saved 44% of procedures, missed no abnormalities with an overall
diagnosis detection rate of 9.8%(69/700). This algorithm was validated
in a separate cohort of 63 patients; applying it would have saved
46%(29/63) of cystoscopies with a positive diagnostic rate of 9.5% and
no missed findings. Conclusion: To our knowledge this is one of the
largest studies reporting the outcomes of investigations for UTI and
rUTI. Our result suggests that imaging is a useful baseline assessment,
but cystoscopy should be limited to specific subgroups. We propose and
validate a simple decision algorithm to manage investigations for
referrals for UTI in secondary care.