Point-of-care tests for urinary tract infections to reduce antimicrobial resistance: a systematic review and conceptual economic model

Background:
Urinary tract infections are diagnosed by general practitioners based on symptoms, dipstick tests in some and laboratory urine culture. Patients may be given inappropriate antibiotics. Point-of-care tests can diagnose urinary tract infection in near-patient settings quicker than standard culture. Some can identify the causative pathogen or antimicrobial sensitivity.

Objective:
To assess whether point-of-care tests for people with suspected urinary tract infection have the potential to be clinically effective and cost-effective to the NHS.

Design:
Systematic review and conceptual economic model.

Results:
Two randomised controlled trials evaluated Flexicult Human (one against standard care; one against ID Flexicult). One trial found no evidence of a difference between groups in concordant antibiotic use (odds ratio 0.84, 95% confidence interval 0.58 to 1.20), and the other found no difference in appropriate antibiotic prescribing (odds ratio 1.44, 95% confidence interval 1.03 to 1.99). Compared with standard care, Flexicult was associated with reduced antibiotic prescribing at initial consultation (odds ratio 0.56, 95% confidence interval 0.35 to 0.88). No difference was found for other outcomes. Sixteen studies reported test accuracy data. Most were rated as being at unclear or high risk of bias. We identified data on three rapid tests (results < 40 minutes). Lodestar DX (n = 1) had good sensitivity (86%, 95% confidence interval 74% to 99%) and specificity (88%, 95% confidence interval 83% to 94%) for detecting Escherichia coli. Uriscreen (n = 4) had modest summary sensitivity (74%, 95% confidence interval 59% to 84%) and specificity (64%, 95% confidence interval 41% to 82%). UTRiPLEX (n = 1) had poor sensitivity (21%) and good specificity (94%). Twelve studies evaluated culture-based tests (results 24 hours). Laboratory-based studies found Dipstreak (n = 2) and Uricult (n = 1) to be highly accurate, but there were limitations with these studies. Uricult Trio (n = 3) had more modest summary sensitivity (73%, 95% confidence interval 63% to 82%) and specificity (70%, 95% confidence interval 52% to 84%). Summary sensitivity for Flexicult Human (n = 4) and ID Flexicult (n = 2) was 79% (95% confidence interval 72% to 85%) and 89% (95% confidence interval 84% to 93%). Summary specificity was 67% (95% confidence interval 30% to 90%) and 70% (95% confidence interval 52% to 84%). Caution is needed in interpreting findings because of heterogeneity and limited data. Five studies evaluated technical performance (Flexicult Human, n = 3; Uricult Trio, n = 2). Limited data suggested that they are easier to use and interpret than standard culture. A conceptual economic model estimated the cost-effectiveness of point-of-care tests for urinary tract infection diagnosis, pathogen identification and antimicrobial sensitivity testing. Sensitivity and specificity of tests were informed by the clinical effectiveness review. Studies identified by the review were screened for evidence on treatment efficacy, costs and utility data; only two studies provided relevant evidence. A pragmatic search identified eight cost-effectiveness studies that provided further evidence. A decision tree comparing point-of-care tests in a mixed population (Lodestar DX vs. Flexicult Human) and in women with uncomplicated urinary tract infection (Lodestar DX vs. Flexicult Human vs. ID Flexicult) was implemented. The available input data were too limited for the results to be meaningful.

Conclusion and future work:
More research is required to determine whether point-of-care tests for urinary tract infection have the potential to be clinically effective and cost-effective to the NHS. Rapid tests such as Astrego PA-100 system and Lodestar DX appear promising, but data are very limited.

Study registration:
This study is registered as PROSPERO CRD42022383889.