Inclusion and exclusion criteria
The studies included were randomised controlled trials comparing at
least two different therapies for the treatment and prevention of POI.
The treatments studied were medicinal treatments. We excluded all
non-medicinal interventions. Studies focusing on peri-operative protocol
management were excluded (e.g. early rehabilitation measures on
post-operative course, enhanced recovery pathways, surgical techniques).
Also excluded were paediatric surgical studies (patients under 18 years
of age), observational studies, reviews, congress abstracts, letters to
the Editor and articles not written in English. The Cochrane
Collaboration tool for assessing risk of bias in randomised controlled
trials was utilised to assess quality of studies7.
Studies with a high risk of bias in one domain (randomisation,
deviations from intended intervention, missing outcome data, measurement
of outcome, selection of the reported results) and in the overall bias
were excluded.