title: Predicting antibiotic prescription after symptomatic treatment for urinary tract infection: development of a model using data from an RCT in general practice.
abstract: BACKGROUND
  Uncomplicated urinary tract infection (UTI) is often treated with antibiotics, resulting in increasing resistance levels. A randomised controlled trial showed that two-thirds of females with UTI treated symptomatically recovered without subsequent antibiotic treatment.
  
  
  OBJECTIVE
  To investigate whether there are differences between females with a UTI who were subsequently prescribed antibiotics and those who recovered with symptomatic treatment only, and to develop a model to predict those who can safely and effectively be treated symptomatically.
  
  
  METHODS
  This is a subgroup analysis of females assigned to ibuprofen in a UTI trial in general practices.
  
  
  METHODS
  Multiple logistic regression analysis was used to select variables for a prediction model, The discriminative value of the model was estimated by the area under the receiver operator curve (AUC) and the effects of different thresholds were calculated within the model predicting antibiotic prescription and need for follow-up visits.
  
  
  RESULTS
  Of the 235 females in the ibuprofen group, 79 were subsequently prescribed antibiotics within 28 days of follow-up. The final model included five predictors: urgency/frequency, impaired daily activities, and positive dipstick test results for erythrocytes, leucocytes, and nitrite. The AUC was 0.73 (95% CI = 0.67 to 0.80). A reasonable threshold for antibiotic initiation would result in 58% of females presenting with UTI being treated with antibiotics. Of the remaining females, only 6% would return to the practice because of symptomatic treatment failure.
  
  
  CONCLUSIONS
  The present model revealed moderately good accuracy and could be the basis for a decision aid for GPs and females to find the treatment option that fits best.
authors.affiliation: Department of General Practice, Göttingen University Medical Center, Göttingen, Germany.
authors.forename: Ildikó
authors.initials: I
authors.lastname: Gágyor
authors.affiliation: Department of General Practice/Family Medicine, Philipps University Marburg, Marburg, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Haasenritter
authors.affiliation: Institute of General Practice, Hannover Medical School, Hannover, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Bleidorn
authors.affiliation: Ray D Wolfe Department of Family Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Warren
authors.initials: W
authors.lastname: McIsaac
authors.affiliation: Institute for Public Health and Nursing Research, Department for Health Services Research, University of Bremen, Bremen, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Schmiemann
authors.affiliation: Department of General Practice, Göttingen University Medical Center, Göttingen, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Hummers-Pradier
authors.affiliation: Department of General Practice, Göttingen University Medical Center, Göttingen, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Himmel
mesh_terms: D000328:Adult; D000892:Anti-Infective Agents, Urinary / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D019540:Area Under Curve; D004311:Double-Blind Method; D004352:Drug Resistance, Microbial; D005260:Female; D005500:Follow-Up Studies; D058006:General Practice; D006801:Humans; D007052:Ibuprofen / Q000627:therapeutic use*; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D014552:Urinary Tract Infections / Q000188:drug therapy*
chemical_list: D000892:Anti-Infective Agents, Urinary; D000894:Anti-Inflammatory Agents, Non-Steroidal; D007052:Ibuprofen
keywords: family practice; ibuprofen; prediction model; urinary anti-infective agents; urinary tract infections