2 Finding evidence

2 Finding evidence

2.1 There will be no systematic literature search. Reuse existing guidance far as possible.

2.2 Little information is likely to be available specifically on COVID-19. Use information on related infections, in particular severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and pandemic influenza.

2.3 Adopt a targeted approach and search all of following:

  • WHO COVID-19 guidance

  • Public Health England guidance and advice

  • NICE guidance

  • NICE-accredited guidance via NICE Evidence Search

  • MHRA or National Patient Safety Alerts, or other official advice (for example on infection control and prevention)

  • guidance from professional bodies and royal colleges, prioritised as follows:

    • guidance from organisations within the UK

    • guidance from organisations in other countries as required.

2.4 If no answer is found from the sources listed, search:

  • the WHO database of publications on coronavirus disease (COVID-19)

  • Medline and Cochrane Database of Systematic of Reviews to identify published literature. Search strategies were adapted from a strategy previously developed by Public Health England (see Appendix A for details of the search used by NICE). Use a simple hierarchy:

    • prioritise systematic reviews and meta-analyses

    • if no systematic reviews or meta-analyses are available, use randomised controlled trials

    • if no randomised controlled trial data are available, include observational studies

    • if no observational data are available, use published expert opinion.

  • If no published evidence is identified, reviewers will provide expert input through NHS England's Clinical Reference Groups.

2.5 There will be no formal risk of bias assessment of the evidence and GRADE will not be used to assess the quality of the outcomes.