Intended for healthcare professionals

CCBYNC Open access

Antibiotic prescription strategies and adverse outcome for uncomplicated lower respiratory tract infections: prospective cough complication cohort (3C) study

BMJ 2017; 357 doi: (Published 22 May 2017) Cite this as: BMJ 2017;357:j2148
  1. Paul Little, professor of primary care research1,
  2. Beth Stuart, statistician1,
  3. Sue Smith, study coordinator2,
  4. Matthew J Thompson, professor in family medicine3,
  5. Kyle Knox, general practitioner2,
  6. Ann van den Bruel, associate professor of general practice2,
  7. Mark Lown, clinical lecturer1,
  8. Michael Moore, professor of general practice1,
  9. David Mant, emeritus professor of general practice2
  1. 1University of Southampton, Primary Care Medical Group, PCPS Unit, Aldermoor Health Centre, Southampton SO16 5ST, UK
  2. 2Nuffield Department of Primary Health Care Sciences, University of Oxford, Radcliffe Observatory Quarter, Oxford, UK
  3. 3University of Washington, Seattle WA, USA
  1. Correspondence to: P Little p.little{at}
  • Accepted 24 April 2017


Objective To assess the impact on adverse outcomes of different antibiotic prescribing strategies for lower respiratory tract infections in people aged 16 years or more.

Design Prospective cohort study.

Setting UK general practice.

Participants 28 883 patients with lower respiratory tract infection; symptoms, signs, and antibiotic prescribing strategies were recorded at the index consultation.

Main outcome measures The main outcomes were reconsultation with symptoms of lower respiratory tract infection in the 30 days after the index consultation, hospital admission, or death. Multivariable analysis controlled for an extensive list of variables related to the propensity to prescribe antibiotics and for clustering by doctor.

Results Of the 28 883 participants, 104 (0.4%) were referred to hospital for radiographic investigation or admission, or both on the day of the index consultation, or were admitted with cancer. Of the remaining 28 779, subsequent hospital admission or death occurred in 26/7332 (0.3%) after no antibiotic prescription, 156/17 628 (0.9%) after prescription for immediate antibiotics, and 14/3819 (0.4%) after a prescription for delayed antibiotics. Multivariable analysis documented no reduction in hospital admission and death after immediate antibiotics (multivariable risk ratio 1.06, 95% confidence interval 0.63 to 1.81, P=0.84) and a non-significant reduction with delayed antibiotics (0.81, 0.41 to 1.64, P=0.61). Reconsultation for new, worsening, or non-resolving symptoms was common (1443/7332 (19.7%), 4455/17 628 (25.3%), and 538/3819 (14.1%), respectively) and was significantly reduced by delayed antibiotics (multivariable risk ratio 0.64, 0.57 to 0.72, P<0.001) but not by immediate antibiotics (0.98, 0.90 to 1.07, P=0.66).

Conclusion Prescribing immediate antibiotics may not reduce subsequent hospital admission or death for young people and adults with uncomplicated lower respiratory tract infection, and such events are uncommon. If clinicians are considering antibiotics, a delayed prescription may be preferable since it is associated with a reduced number of reconsultations for worsening illness.


  • We thank Jan Charlwood for discussing and agreeing the main focus of the programme; Terry Hamer for early input into the protocols, commenting on patient materials, and suggesting key outcomes; Samantha Richards-Hall for commenting on materials and participating in regular management meetings for overseeing the programme; the local general practitioners who promoted the study; and the doctors, practices, and patients who participated.

  • Contributors: SS developed the protocol; provided day to day overall management of the study; coordinated recruitment, follow-up, and data entry; and commented on drafts of the paper. PL had the original idea for the protocol, led the funding application, supervised the running of the study, contributed to the analysis, led the drafting of the paper, and is the guarantor for the paper. DM had the original idea for the study, led the original development of the protocol for the funding application, led the further protocol development and ethics submission, provided overall supervision of the study, and contributed to the analysis and the drafting of the paper. MM developed the protocol for funding and contributed to the management of the study, developing the detailed plan for analysis, and the drafting of the paper. MJT, with SS and DM, led the development of the protocol for ethical approval, supervised the study, and contributed to the analysis and drafting of the paper. KK, AvdB, and ML helped develop the protocol and contributed to developing the detailed plan for analysis, the analysis, and the drafting of the paper. BS developed the analysis protocol and led the quantitative analysis with DM and PL, and drafted the paper with PL.

  • Funding: This article presents independent research funded by the National Institute for Health Research (NIHR) under its programme grants for applied research programme (reference No RP-PG-0407-10098). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health. The University of Southampton was the sponsor, but neither it nor the funder had any role in the running of the study, the analysis, the write-up, or the interpretation of the results.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare: no support from any other organisations (other than the NIHR service support detailed in the funding section) for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: This study was approved by the Oxfordshire research ethics committee (A 09/HO604/67).

  • Data sharing: No additional data available.

  • Transparency: The manuscript’s guarantor (PL) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See:

View Full Text