Which near-patient tests might improve the diagnosis of UTI in older people in urgent care settings? A mapping review and consensus process

Purpose: The aim of this study was to map out the existing knowledge on near-patient tests for urinary tract infections, and use a consensus building approach to identify those which might be worthy of further evaluation in the urgent care context, defined as clinically useful and feasible results available within 4–24 h. Methods: A systematic search for reviews describing diagnostic tests for UTI was undertaken in Medline, EMBASE, Cochrane database of systematic reviews and CINAHL selected reviews were retained according to a priori inclusion and exclusion criteria, and then graded for quality using the CASP tool for reviews. A consensus process involving microbiologists and chemical pathologists helped identify which test might conceivably be applied in the urgent care context (e.g. Emergency Department, giving results within 24 h). Results: The initial search identified 1079 papers, from which 26 papers describing 35 diagnostic tests were retained for review. The overall quality was limited, with only 7/26 retained papers scoring more than 50% on the CASP criteria. Reviews on urine dipstick testing reported wide confidence intervals for sensitivity and specificity; several raised concerns about urine dip testing in older people. A number of novel biomarkers were reported upon but appeared not to be helpful in differentiating infection from asymptomatic bacteriuria. Blood markers such as CRP and procalcitonin were reported to be helpful in monitoring rather than diagnosing UTI. The consensus process helped to refine the 35 test down to 17 that might be useful in the urgent care context: urinalysis (nitrites and leucocytes), uriscreen catalase test, lactoferrin, secretory immunoglobulin A, xanthine oxidase, soluble triggering receptor expressed on myeloid cells, A-1 microglobulin (a1 Mg) and a1 Mg/creatinine ratio, cytokine IL-6, RapidBac, MALDI-TOF, electronic noses, colorimetric sensor arrays, electro chemical biosensor, WBC count (blood), C-reactive peptide, erythrocyte sedimentation rate. Conclusions: A wide range of diagnostic tests have been explored to diagnose UTI, but, in general, have been poorly evaluated or have wide variation in predictive properties. This study identified 17 tests for UTI that seemed to offer some primes and merit further evaluation for diagnosing UTI in older people in urgent care settings.