title: The impact of empirical management of acute cystitis on unnecessary antibiotic use.
abstract: BACKGROUND
  Guidelines for the management of acute cystitis support empirical antibiotic treatment; however, up to half of symptomatic women have negative urine cultures.
  
  
  OBJECTIVE
  To determine whether empirical treatment leads to unnecessary antibiotic prescriptions in women with symptoms of acute cystitis.
  
  
  METHODS
  A cohort of 231 women (defined as females aged 16 years and older) presenting to family physicians' offices with symptoms of cystitis underwent a standardized clinical assessment, urine dip testing, and culture. Recommendations for urine testing and antibiotic treatment under 3 empirical strategies were compared with observed physician management and a logistic regression model for the outcomes of antibiotic prescriptions, urine culture testing, and unnecessary antibiotics, defined as a prescription where the subsequent urine culture was negative.
  
  
  RESULTS
  There were 123 positive urine cultures (53.3%). Physicians prescribed antibiotics to 186 women (80.9%), of whom 74 (39.8%) were culture negative. Unnecessary antibiotic use was similar for 2 guidelines recommending empirical antibiotic treatment without testing for pyuria (41.4% and 40.6%). Treating women with classic cystitis symptoms and pyuria would have decreased unnecessary antibiotic use (26.2%; P =.02) but resulted in fewer women with confirmed urinary tract infection receiving immediate antibiotics (66.4% vs 91.8% usual care; P<.001). A derived prediction model incorporating testing for pyuria and nitrites would also have reduced unnecessary antibiotic use (27.5%; P =.03), but more women with confirmed urinary tract infection would have received immediate antibiotics (81.3%; P =.01).
  
  
  CONCLUSIONS
  Empirical antibiotic treatment of acute cystitis in women without testing for pyuria promotes unnecessary antibiotic use. A simple decision rule provides for prompt treatment of infected women while reducing antibiotic overuse and unnecessary urine testing.
authors.affiliation: Mt Sinai Family Medicine Centre, 600 University Ave, Room 413, Toronto, Ontario, Canada M5G 1X5. mcisaac@mtsinai.on.ca
authors.forename: Warren J
authors.initials: WJ
authors.lastname: McIsaac
authors.forename: Donald E
authors.initials: DE
authors.lastname: Low
authors.forename: Anne
authors.initials: A
authors.lastname: Biringer
authors.forename: Nicholas
authors.initials: N
authors.lastname: Pimlott
authors.forename: Michael
authors.initials: M
authors.lastname: Evans
authors.forename: Richard
authors.initials: R
authors.lastname: Glazier
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003556:Cystitis / Q000175:diagnosis / Q000188:drug therapy* / Q000652:urine*; D004363:Drug Utilization; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies