Clinical accuracy of point-of-care urine culture in general practice

Abstract

ObjectiveTo assess the clinical accuracy (sensitivity (SEN), specificity (SPE), positive predictive value and negative predictive value) of two point-of-care (POC) urine culture tests for the identification of urinary tract infection (UTI) in general practice.DesignProspective diagnostic accuracy study comparing two index tests (Flexicult™ SSI-Urinary Kit or ID Flexicult™) with a reference standard (urine culture performed in the microbiological department).SettingGeneral practice in the Copenhagen area patients. Adult female patients consulting their general practitioner with suspected uncomplicated, symptomatic UTI.Main outcome measures(1) Overall accuracy of POC urine culture in general practice. (2) Individual accuracy of each of the two POC tests in this study. (3) Accuracy of POC urine culture in general practice with enterococci excluded, since enterococci are known to multiply in boric acid used for transportation for the reference standard. (4) Accuracy based on expert reading of photographs of POC urine cultures performed in general practice. Standard culture performed in the microbiological department was used as reference standard for all four measures.ResultsTwenty general practices recruited 341 patients with suspected uncomplicated UTI. The overall agreement between index test and reference was 0.76 (CI: 0.71–0.80), SEN 0.88 (CI: 0.83–0.92) and SPE 0.55 (CI: 0.46–0.64). The two POC tests produced similar results individually. Overall agreement with enterococci excluded was 0.82 (0.77–0.86) and agreement between expert readings of photographs and reference results was 0.81 (CI: 0.76–0.85).ConclusionsPOC culture used in general practice has high SEN but low SPE. Low SPE could be due to both misinterpretation in general practice and an imperfect reference standard.Registration numberClinicalTrials.gov NCT02323087.

Point-of-care urine culture for managing urinary tract infection in primary care: a randomised controlled trial of clinical and cost-effectiveness

“…The authors have previously examined the analytic performance of the Flexicult test using routinely submitted urine samples, 31 and the analytic performance of other POCT culture approaches have also been assessed. 19,[32][33][34] However, it was not possible to identify previous evaluations of intervention implementation to improve the management of UTI in terms of inappropriate antibiotic use, costs, resistance, and health outcomes. Holm et al have also found that POC culture was better at ruling in, rather than ruling out, a UTI diagnosis based on laboratory culture.…”

“…Holm et al have also found that POC culture was better at ruling in, rather than ruling out, a UTI diagnosis based on laboratory culture. 34…”

Effect of point-of-care susceptibility testing in general practice on appropriate prescription of antibiotics for patients with uncomplicated urinary tract infection: a diagnostic randomised controlled trial

“…The reference, sending urine in boric acid for culture at the microbiological laboratory, has its flaws as previously described. 22 However, these flaws should have a similar effect on the two groups, since the distribution of growth and the resistance pattern did not differ significantly between groups.…”

“…Bias in the interpretation of the test was low as described previously. 22 GPs were blinded to the result of the reference at the time of deciding on treatment; POC test and reference were performed on the same portion of urine; the reference was adequate for ruling disease in or out and all data were included in the analysis. Allocation was concealed using sealed envelopes.…”

A new point-of-care test for the rapid detection of urinary tract infections

“…As a whole, results obtained in this study have highlighted the robustness of the MBS POCT for the detection of suspected UTIs and suggest how its rapidity, simplicity, and user-friendliness could represent key advantages for the clinical management of patients before a UTI is confirmed by culture-based laboratory methods. By comparison with available devices for UTI detection [33][34][35][36][37], it appears that the MBS POCT could place well among other culture-based devices thanks to its ability to combine short analytical time and high accuracy.…”