The safety of Delayed versus immediate antibiotic prescribing for upper respiratory tract infections

Tjeerd Pieter Van Staa*, Victoria Palin, Benjamin Brown, William Welfare, Yan Li, Darren M. Ashcroft

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)
    47 Downloads (Pure)


    BACKGROUND: This study aimed to evaluate the clinical safety of delayed antibiotic prescribing for upper respiratory tract infections (URTIs), which is recommended in treatment guidelines for less severe cases. 

    METHODS: Two population-based cohort studies used the English Clinical Practice Research Databank and Welsh Secure Anonymized Information Linkage, containing electronic health records from primary care linked to hospital admission records. Patients with URTI and prescriptions of amoxicillin, clarithromycin, doxycycline, erythromycin, or phenoxymethylpenicillin were identified. Patients were stratified according to delayed and immediate prescribing relative to URTI diagnosis. Outcome of interest was infection-related hospital admission after 30 days. 

    RESULTS: The population included 1.82 million patients with an URTI and antibiotic prescription; 91.7% had an antibiotic at URTI diagnosis date (immediate) and 8.3% had URTI diagnosis in 1-30 days before (delayed). Delayed antibiotic prescribing was associated with a 52% increased risk of infection-related hospital admissions (adjusted hazard ratio, 1.52; 95% confidence interval, 1.43-1.62). The probability of delayed antibiotic prescribing was unrelated to predicted risks of hospital admission. Analyses of the number needed to harm showed considerable variability across different patient groups (median with delayed antibiotic prescribing, 1357; 2.5% percentile, 295; 97.5% percentile, 3366). 

    CONCLUSIONS: This is the first large population-based study examining the safety of delayed antibiotic prescribing. Waiting to treat URTI was associated with increased risk of hospital admission, although delayed antibiotic prescribing was used similarly between high- and low-risk patients. There is a need to better target delayed antibiotic prescribing to URTI patients with lower risks of complications.

    Original languageEnglish
    Pages (from-to)E394-E401
    JournalClinical Infectious Diseases
    Issue number2
    Early online date29 Jun 2020
    Publication statusPublished - 15 Jul 2021

    Bibliographical note

    Financial Information: Connected Health Cities is a Northern Health Science Alliance–led program funded by the Department of Health and delivered by a consortium of academic and NHS organizations across the north of England. This study is partly based on data from the Clinical Practice Research Datalink obtained under license from the MHRA. The data are provided by patients and collected by the NHS as part of their care and support. This study also used anonymized data held in the SAIL system, which is part of the national e-health records infrastructure for Wales.

    Open Access: This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (, which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact [email protected]

    Publisher Copyright: © The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.

    Citation: Tjeerd Pieter van Staa, Victoria Palin, Benjamin Brown, William Welfare, Yan Li, Darren M Ashcroft, The Safety of Delayed Versus Immediate Antibiotic Prescribing for Upper Respiratory Tract Infections, Clinical Infectious Diseases, Volume 73, Issue 2, 15 July 2021, Pages e394–e401,



    • Antibiotics
    • Effectiveness
    • Epidemiology
    • Primary care
    • Upper respiratory tract infections


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