title: Safety of reduced antibiotic prescribing for self limiting respiratory tract infections in primary care: cohort study using electronic health records.
abstract: OBJECTIVE
  To determine whether the incidence of pneumonia, peritonsillar abscess, mastoiditis, empyema, meningitis, intracranial abscess, and Lemierre's syndrome is higher in general practices that prescribe fewer antibiotics for self limiting respiratory tract infections (RTIs).
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  610 UK general practices from the UK Clinical Practice Research Datalink.
  
  
  METHODS
  Registered patients with 45.5 million person years of follow-up from 2005 to 2014.
  
  
  METHODS
  Standardised proportion of RTI consultations with antibiotics prescribed for each general practice, and rate of antibiotic prescriptions for RTIs per 1000 registered patients.
  
  
  METHODS
  Incidence of pneumonia, peritonsillar abscess, mastoiditis, empyema, meningitis, intracranial abscess, and Lemierre's syndrome, adjusting for age group, sex, region, deprivation fifth, RTI consultation rate, and general practice.
  
  
  RESULTS
  From 2005 to 2014 the proportion of RTI consultations with antibiotics prescribed decreased from 53.9% to 50.5% in men and from 54.5% to 51.5% in women. From 2005 to 2014, new episodes of meningitis, mastoiditis, and peritonsillar abscess decreased annually by 5.3%, 4.6%, and 1.0%, respectively, whereas new episodes of pneumonia increased by 0.4%. Age and sex standardised incidences for pneumonia and peritonsillar abscess were higher for practices in the lowest fourth of antibiotic prescribing compared with the highest fourth. The adjusted relative risk increases for a 10% reduction in antibiotic prescribing were 12.8% (95% confidence interval 7.8% to 17.5%, P<0.001) for pneumonia and 9.9% (5.6% to 14.0%, P<0.001) for peritonsillar abscess. If a general practice with an average list size of 7000 patients reduces the proportion of RTI consultations with antibiotics prescribed by 10%, then it might observe 1.1 (95% confidence interval 0.6 to 1.5) more cases of pneumonia each year and 0.9 (0.5 to 1.3) more cases of peritonsillar abscess each decade. Mastoiditis, empyema, meningitis, intracranial abscess, and Lemierre's syndrome were similar in frequency at low prescribing and high prescribing practices.
  
  
  CONCLUSIONS
  General practices that adopt a policy to reduce antibiotic prescribing for RTIs might expect a slight increase in the incidence of treatable pneumonia and peritonsillar abscess. No increase is likely in mastoiditis, empyema, bacterial meningitis, intracranial abscess, or Lemierre's syndrome. Even a substantial reduction in antibiotic prescribing was predicted to be associated with only a small increase in numbers of cases observed overall, but caution might be required in subgroups at higher risk of pneumonia.
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, Guy's Campus, London SE1 1UL, UK martin.gulliford@kcl.ac.uk.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Gulliford
authors.affiliation: Academic Unit for Primary Care and Population Sciences, University of Southampton, Southampton, UK.
authors.forename: Michael V
authors.initials: MV
authors.lastname: Moore
authors.affiliation: Academic Unit for Primary Care and Population Sciences, University of Southampton, Southampton, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Little
authors.affiliation: Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK.
authors.forename: Alastair D
authors.initials: AD
authors.lastname: Hay
authors.affiliation: The Health Centre, Bicester, Oxford, UK.
authors.forename: Robin
authors.initials: R
authors.lastname: Fox
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
authors.forename: A Toby
authors.initials: AT
authors.lastname: Prevost
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
authors.forename: Dorota
authors.initials: D
authors.lastname: Juszczyk
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
authors.forename: Judith
authors.initials: J
authors.lastname: Charlton
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Ashworth
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015331:Cohort Studies; D057286:Electronic Health Records; D004653:Empyema / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D058006:General Practice / Q000706:statistics & numerical data; D006801:Humans; D057970:Inappropriate Prescribing / Q000706:statistics & numerical data*; D015994:Incidence; D057831:Lemierre Syndrome / Q000188:drug therapy / Q000453:epidemiology; D008297:Male; D008417:Mastoiditis / Q000188:drug therapy / Q000453:epidemiology; D008581:Meningitis / Q000188:drug therapy / Q000453:epidemiology; D061214:Patient Safety; D000039:Peritonsillar Abscess / Q000188:drug therapy / Q000453:epidemiology; D011014:Pneumonia / Q000188:drug therapy / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents