These guidelines were updated in accordance with the WHO handbook for guideline development, 2012 (18). The process comprised multiple steps, including setting up a guideline development group, scoping the revision of the document, and setting up an external expert review group to guide the systematic reviews using the PICOT framework (which clearly defined the IPC intervention in terms of question, population, comparator and outcome), and the conduct of the systematic reviews, including evidence retrieval and synthesis. Where systematic reviews could not be undertaken, evidence-based reviews or critical appraisals of the literature were done instead. Evidence was synthesized and recommendations formulated using the GRADE framework (18, 46-50).

Major systematic reviews of relevance to these guidelines are summarized in Annex L, and the evidence profiles of individual studies are available in the published papers (51, 130, 149, 207).

The tables that make up the remainder of this annex summarize the assessment of evidence and other important factors that support the content and strength of key recommendations according to the GRADE framework (18, 46-50). These tables were drafted after careful review of existing evidence, and were extensively reviewed by expert members of the Global Infection Prevention and Control Network. The topics covered by the tables are:

Table K.1. Considerations for clinical triage and early identification (PDF, 324K)

Table K.2. Considerations for respiratory hygiene (PDF, 396K)

Table K.3. Considerations for spatial separation (PDF, 395K)

Table K.4. Considerations for cohorting and special measures (PDF, 395K)

Table K.5. Considerations for personal protective equipment (PDF, 326K)

Table K.6. Considerations for personal protective equipment for aerosol-generating procedures (PDF, 399K)

Table K.7. Considerations for environmental ventilation for aerosol-generating procedures (PDF, 396K)

Table K.8. Considerations for vaccination of health-care workers (PDF, 324K)

Table K.9. Considerations for ultraviolet germicidal irradiation (PDF, 323K)

Table K.10. Considerations for duration of additional infection prevention and control (IPC) precautions (PDF, 395K)

Where consensus was reached that benefits clearly outweighed harms, there was no major variability of values and preferences, and the feasibility of recommendations was high, the factors were labelled as favourable, providing rationale for making a strong recommendation. The same label was assigned where the recommendations were considered not too resource-intensive. Where there was uncertainty about the balance of benefits versus harms, values and preferences, resource implications, and feasibility, the factors were labelled as conditional.

Recommendations were considered strong when the guideline development group was confident that the desirable effects of adherence outweigh the undesirable effects. Recommendations were labelled as conditional when the desirable effects of adherence were deemed to probably outweigh any undesirable effects, but the group was not confident about the trade-off.