title: Nappy pad urine samples for investigation and treatment of UTI in young children: the 'DUTY' prospective diagnostic cohort study.
abstract: BACKGROUND
  The added diagnostic utility of nappy pad urine samples and the proportion that are contaminated is unknown.
  
  
  OBJECTIVE
  To develop a clinical prediction rule for the diagnosis of urinary tract infection (UTI) based on sampling using the nappy pad method.
  
  
  METHODS
  Acutely unwell children <5 years presenting to 233 UK primary care sites.
  
  
  METHODS
  Logistic regression to identify independent associations of symptoms, signs, and urine dipstick test results with UTI; diagnostic utility quantified as area under the receiver operator curves (AUROC). Nappy pad rule characteristics, AUROC, and contamination, compared with findings from clean-catch samples.
  
  
  RESULTS
  Nappy pad samples were obtained from 3205 children (82% aged <2 years; 48% female), culture results were available for 2277 (71.0%) and 30 (1.3%) had a UTI on culture. Female sex, smelly urine, darker urine, and the absence of nappy rash were independently associated with a UTI, with an internally-validated, coefficient model AUROC of 0.81 (0.87 for clean-catch), which increased to 0.87 (0.90 for clean-catch) with the addition of dipstick results. GPs' 'working diagnosis' had an AUROC 0.63 (95% confidence intervals [CI] = 0.53 to 0.72). A total of 12.2% of nappy pad and 1.8% of clean-catch samples were 'frankly contaminated' (risk ratio 6.66; 95% CI = 4.95 to 8.96; P<0.001).
  
  
  CONCLUSIONS
  Nappy pad urine culture results, with features that can be reported by parents and dipstick tests, can be clinically useful, but are less accurate and more often contaminated compared with clean-catch urine culture.
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Oxford, and GP, Cwm Taf University Health Board.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Butler
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: Jonathan Ac
authors.initials: JA
authors.lastname: Sterne
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: Michael
authors.initials: M
authors.lastname: Lawton
authors.affiliation: Division of Population Medicine, School of Medicine, Cardiff University, Cardiff.
authors.forename: Kathryn
authors.initials: K
authors.lastname: O'Brien
authors.affiliation: Specialist Antimicrobial Chemotherapy Unit, Public Health Wales Microbiology Cardiff, University Hospital Wales, Cardiff.
authors.forename: Mandy
authors.initials: M
authors.lastname: Wootton
authors.affiliation: South East Wales Trials Unit (SEWTU), Centre for Trials Research, Cardiff University, Cardiff.
authors.forename: Kerenza
authors.initials: K
authors.lastname: Hood
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: William
authors.initials: W
authors.lastname: Hollingworth
authors.affiliation: Primary Care and Population Sciences Division, University of Southampton, Southampton.
authors.forename: Paul
authors.initials: P
authors.lastname: Little
authors.affiliation: Department of Surgery and Cancer, Imperial College, St Mary's Hospital, London.
authors.forename: Brendan C
authors.initials: BC
authors.lastname: Delaney
authors.affiliation: Department of Paediatrics and Child Health, University Hospital of Wales, Cardiff.
authors.forename: Judith
authors.initials: J
authors.lastname: van der Voort
authors.affiliation: Bristol Royal Hospital for Children, University Hospitals Bristol, NHS Foundation Trust, Bristol.
authors.forename: Jan
authors.initials: J
authors.lastname: Dudley
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: Kate
authors.initials: K
authors.lastname: Birnie
authors.affiliation: South East Wales Trials Unit (SEWTU), Centre for Trials Research, Cardiff University, Cardiff.
authors.forename: Timothy
authors.initials: T
authors.lastname: Pickles
authors.affiliation: South East Wales Trials Unit (SEWTU), Centre for Trials Research, Cardiff University, Cardiff.
authors.forename: Cherry-Ann
authors.initials: CA
authors.lastname: Waldron
authors.affiliation: Centre for Academic Primary Care, NIHR School of Primary Care Research, School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: Harriet
authors.initials: H
authors.lastname: Downing
authors.affiliation: South East Wales Trials Unit (SEWTU), Centre for Trials Research, Cardiff University, Cardiff.
authors.forename: Emma
authors.initials: E
authors.lastname: Thomas-Jones
authors.affiliation: South East Wales Trials Unit (SEWTU), Centre for Trials Research, Cardiff University, Cardiff.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lisles
authors.affiliation: Primary Care and Population Sciences Division, University of Southampton, Southampton.
authors.forename: Kate
authors.initials: K
authors.lastname: Rumsby
authors.affiliation: King's College London, Division of Health and Social Care Research, Department of Primary Care and Public Health Sciences, London.
authors.forename: Stevo
authors.initials: S
authors.lastname: Durbaba
authors.affiliation: NIHR CLAHRC West, University Hospitals Bristol NHS Foundation Trust, Bristol.
authors.forename: Penny
authors.initials: P
authors.lastname: Whiting
authors.affiliation: Primary Care and Population Sciences Division, University of Southampton, Southampton.
authors.forename: Kim
authors.initials: K
authors.lastname: Harman
authors.affiliation: Specialist Antimicrobial Chemotherapy Unit, Public Health Wales Microbiology Cardiff, University Hospital Wales, Cardiff.
authors.forename: Robin
authors.initials: R
authors.lastname: Howe
authors.affiliation: North Bristol NHS Trust, Southmead Hospital, Bristol.
authors.forename: Alasdair
authors.initials: A
authors.lastname: MacGowan
authors.affiliation: University of the West of England, Bristol with University Hospitals Bristol, NHS Foundation Trust, Bristol.
authors.forename: Margaret
authors.initials: M
authors.lastname: Fletcher
authors.affiliation: Centre for Academic Primary Care, NIHR School of Primary Care Research, School of Social and Community Medicine, University of Bristol, Bristol.
authors.forename: Alastair D
authors.initials: AD
authors.lastname: Hay
mesh_terms: D002675:Child, Preschool; D041381:Diapers, Infant / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011320:Primary Health Care; D011446:Prospective Studies; D013048:Specimen Handling / Q000379:methods*; D006113:United Kingdom; D016482:Urinalysis; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000652:urine
keywords: antibacterial agents; diagnosis; infant; paediatrics; primary health care; urinary tract infections