A. Preston et al., Screening for urinary tract infections in a gynaecological setting: validity and cost-effectiveness of reagent strips, BR J BIOMED, 56(4), 1999, pp. 253-257
This study aims to test the validity and cost-effectiveness of reagent-stri
p analysis compared with microbiological laboratory testing for mass screen
ing of urine for urinary tract infections in a gynaecological setting. Over
a six-month period, urine samples from a convenient group of 228 women pre
senting in a gynaecological ward of an NHS Trust hospital were tested using
Ames 8SG reagent strips to detect leucocyte esterase and nitrite. Total ba
cterial counts were also carried out; urine culture was recorded as positiv
e if there was > 10(5) organisms/mL. Validity of the dipstick tests was mea
sured, using four criteria (sensitivity, specificity, positive predictive v
alue [PPV] and negative predictive value [NPV]), against the results of lab
oratory analysis. The combined use of the leucocyte esterase and nitrite te
sts produced results as follows: sensitivity, 96.4%; specificity,- 88.5%; P
PV, 54%; and NPV, 99.4%. Cost-effectiveness for visible costs was calculate
d as 48.6% for the 12.3% rate of infection in this study. The use of reagen
t strips in a mass-screening programme in a gynaecological setting proved b
oth valid and cost-effective.