Data extraction
All titles were screened by one reviewer (JW) and potentially-relevant
titles were retained. Two reviewers (JW, RH) independently screened
shortlisted abstracts, with any conflicts resolved by team discussion.
Full texts were obtained for these titles, and a final decision on
inclusion or exclusion was made for each of these titles following full
text review against the eligibility criteria. Data extracted from
studies selected for inclusion were first author, publication year,
country, study objective, sample, methods, key study findings and links
to efficiency improvement.