Best methods for urine sample collection for diagnostic accuracy in women with urinary tract infection symptoms: a systematic review

BACKGROUND

Most guidelines recommend a midstream urine (MSU) or a midstream clean-catch (MSCC) sample for urinalysis. However, whether this sample is better than others is still controversial.

OBJECTIVES

To assess the most adequate non-invasive method to collect a urine specimen for diagnosing urinary tract infections (UTI) in symptomatic non-pregnant women.

METHODS

This review was conducted according to the Systematic Reviews of Diagnostic Test Accuracy guidelines (PROSPERO CRD42021241758). PubMed was searched paired sample studies and controlled trials. Studies comparing MSCC, MSU without cleaning, first-void urine, and random voiding samples were considered. Studies evaluating invasive methods were excluded. The main outcome was diagnostic accuracy of urine cultures. Contamination rates were evaluated. The risk of bias tool for systematic reviews on diagnostic accuracy (QUADAS-2) was assessed.

RESULTS

Six studies including 1,010 patients were evaluated. Only two studies used paired samples. No study was considered as having low risk of bias. There was no difference in contamination for MSU specimens collected with or without cleansing and between random void urine collection and MSCC. In one study comparing first-void urine with MSU samples, the contamination rate was lower in the latter, but the gold standard of urine culture was only used for one sampling collection.

CONCLUSIONS

To the best of our knowledge, this systematic review is the first to assess the evidence available from different exclusively non-invasive urine sampling. Despite being widely recommended, our review did not find consistent evidence that asking women to provide midstream samples with or without cleansing is better.

Clinical effectiveness and bacteriological eradication of three different Short-COurse antibiotic regimens and single-dose fosfomycin for uncomplicated lower Urinary Tract infections in adult women (SCOUT study): study protocol for a randomised clinical trial

INTRODUCTION

Uncomplicated lower urinary tract infections (uLUTI) are a common problem in primary care. Current local guidelines recommend the use of a single 3 g dose of fosfomycin. However, most general practitioners (GP) prefer short-course therapies to single-dose therapy. No study has compared head-to-head short-course antimicrobial agents for uLUTIs. Therefore, the aim of this randomised clinical trial is to compare three different short-course antibiotic therapies with a single-dose of fosfomycin for these infections.

METHODS AND ANALYSIS

This will be a pragmatic, multicentre, parallel group, open trial. Women aged 18 or older and with symptoms of uLUTI and a positive urine dipstick analysis will be randomised to one of the following four groups: a single dose of 3 g of fosfomycin, 2 days of 3 g of fosfomycin o.d., 3 days of pivmecillinam 400 mg three times per day (t.i.d) or 5 days of nitrofurantoin 100 mg t.i.d. A total sample of 1120 patients was calculated. The primary endpoint is clinical effectiveness at day 7, defined as cure of symptoms reported by the patients in a diary including four symptoms: dysuria, urgency, frequency and suprapubic pain, which will be scored on a 4-point severity scale (not present/mild/moderate/severe). Follow-up visits are scheduled at days 7 (phone call), 14 and 28 for assessing evolution. Urine samples will be collected in the three on-site visits and urine cultures performed. If positive, antibiograms for the three antibiotics studied will be performed. Bacterial eradication will be measured at days 14 and 28.

ETHICS AND DISSEMINATION

The study was approved by the Ethical Board of IDIAP Jordi Gol (reference number: 21/173-AC) and Spanish Agency of Medicines and Medical Devices. The findings of this trial will be disseminated through research conferences and peer-review journals.

TRIAL REGISTRATION NUMBER

NCT04959331; EudraCT Number: 2021-001332-26.

TIME SCHEDULE

January 2022 to April 2023.