Study selection

Before the screening process, records retrieved from the literature searches will be uploaded to Covidence, an online systematic review management software package [56]. To ensure high inter-rater reliability, we will conduct pilot exercises before title and abstract screening and full-text review using the pre-determined eligibility criteria for each KQ. Standardized screening forms for study selection will be developed and tested on a random sample for 50 titles and abstracts and 25 full-text articles by reviewers. Any discrepancies among reviewers will be resolved by discussion or consulting with a third reviewer. Adjustments to the form will be made as needed.

Title and abstract screening will be completed in random order by two reviewers using the liberal accelerated approach [57]. All citations labelled by one reviewer as “included” or “unsure” will move forward to full-text review. The second reviewer will verify the excluded citations considered by the first reviewer to confirm their exclusion. The references for the second reviewer will be randomized to ensure they do not know whether the citation is a first review or verification. Conflict resolution will not be required at this screening stage. Full-text review will be completed in duplicate by pairs of reviewers screening independently. Any discrepancies will be resolved by consensus among the two reviewers or by a third reviewer.

We will order articles that are not available electronically through the interlibrary loan service. Where only abstract information is available, articles will be included if sufficient information is provided. If a potentially relevant study reports information that is unclear for a decision on eligibility, the corresponding author will be contacted for additional information twice by email over 1 month. If no response is received, the article will be excluded. For the excluded articles, the reasons for exclusion will be agreed upon by reviewers and a list of excluded studies with reasons will be provided in the final manuscript. If advice is required on potentially eligible studies, we will consult with the working group and clinical experts on the study design and outcomes collected. Attempts will be made to anonymize the article to avoid study identification and outcome data. The ERSC will decide on the eligibility of these studies.