Determining the feasibility of randomising infants, children and young people to invasive and non-invasive urine sampling techniques (FROG): Protocol for a multicentre randomised controlled feasibility trial and mixed methods perspectives' study of RCT feasibility

Journal article

BackgroundUrinary tract infections (UTI) are the second most common serious bacterial infection in children. When healthcare practitioners are unsure if an infant, child, or young person has a UTI they perform a urine test. A midstream sample is recommended by the National Institute for Health and Care Excellence (NICE) for obtaining urine for testing. However, collecting urine from children who are unable to provide a midstream urine sample is challenging. Samples can be collected either by non-invasive (clean catch) or invasive methods (trans-urethral bladder catheter or suprapubic aspirate). Non-invasive methods are slow and prone to contamination but are painless. Invasive methods are less prone to contamination and are quick but can cause pain and distress.MethodsThis is a mixed methods feasibility study comprising of three parts. Part 1 is a pragmatic multicentre randomised controlled feasibility trial. The trial aims to evaluate the feasibility of conducting an RCT comparing invasive and non-invasive sampling methods for infants, children and young people (N = 100). Resource use will be assessed by parent reported questionnaire and mixed methods descriptors reported by healthcare professionals (n = 24). A cost analysis will assess the urine collection methods, informing a future cost-effectiveness analysis. Part 2 is an embedded mixed methods perspectives' study including interviews with parents (n = 15-20) and children (n = 10-15), five focus groups (n = 6-8 per group) and interviews (n = 10) with healthcare professionals aiming to assess feasibility and acceptability of the trial. Part 3 is a stakeholder (n = 40) consensus meeting determining a final definitive study design.DiscussionThe results of the study will inform a recommendation and decision on progression and design of a definitive RCT for infants, children and young people who have a suspected urine infection but cannot provide a midstream urine sample.Trial registrationInternational Standard Randomised Controlled Trial Number (ISRCTN) 84676764: Feasibility of conducting a randomised controlled trial (RCT) comparing invasive and non-invasive urine sampling techniques in children under 16 years old with a suspected urinary tract infection 1.

Authors: Taylor Miller, P; McDowell, C; Agus, A; Murphy, L; Hartshorn, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Taylor and Francis
• Journal: NIHR Open Research
• Volume: 5
• Pages: 108
• Publication date: 2025-11-21
• Acceptance date: 2025-10-31
• DOI: 10.3310/nihropenres.14114.1
• EISSN: 2633-4402
• ISSN: 2633-4402
• Pmid: 41458561
• Language: English
• Keywords: Urinary tract infection; Rct; Catheter; Suprapubic Aspirate; Paediatric; Feasibility; Clean- Catch