Safety of fast-track rehabilitation after gastrointestinal surgery: Systematic review and meta-analysis

Table 2 Risk-of-bias assessment of the randomized controlled trials

Ref.	Selection bias	Performance bias	Detection bias	Attrition bias	Reporting	Overall risk of bias
Ionescu et al[25]	Low	Low	Low	Low	Low	Low
Ren et et al[26]	Low	Unclear	Low	Low	Low	Low
Yang et al[27]	Low	Low	Low	Unclear	Low	Low
Hübner et al[28]	Low	Low	Low	Low	Low	Low
Wang et al[29]	Low	Low	Low	Low	Unclear	Low
Vlug et al[30]	Unclear	Low	Low	Low	Low	Low
van et al[31]	Low	Low	Low	Low	Unclear	Low
Veenhof et al[32]	Low	Low	Unclear	Low	Low	Low
Serclová et al[33]	Low	Low	Low	Low	Unclear	Low
Muller et al[34]	Low	Low	Low	Low	Unclear	Low
Wang et al[35]	Unclear	Low	Low	Low	Low	Low
Wang et al[36]	Unclear	Low	Low	Low	Low	Low
King et al[38]	Low	Low	Unclear	Low	Low	Low
Faiz et al[37]	Low	Low	Low	Low	Unclear	Low
Srinivasa et al[39]	Low	Unclear	Low	Low	Low	Low
Basse et al[40]	Unclear	Low	Low	Low	Low	Low
MacKay et al[41]	Low	Low	Low	Low	Low	Low
García-Botello et al[42]	Low	Low	Low	Low	Unclear	Low
Anderson et al[43]	Low	Low	Low	Low	Low	Low
Gatt et al[44]	Low	Unclear	Low	Low	Low	Low
Khoo et al[2]	Low	Low	Low	Low	Low	Low
Wang et al[45]	Low	Low	Low	Low	Low	Low
Chen Hu et al[46]	Low	Low	Low	Low	Low	Low
Lemanu et al[47]	Low	Low	Low	Low	Unclear	Low

Selection bias is based on random sequence generation and allocation concealment; performance bias includes blinding of participants and study investigators for the outcomes of interest; detection bias includes blinding of outcome assessors; attrition bias indicates systematic loss of participants in one arm, which could lead to missing outcome data for that trial arm over the other trial arm; and reporting bias includes the possibility of selective outcome reporting. Selection bias is a feature of the trial design. Performance and detection bias are overall low given that most data were collected without any prior knowledge of the investigators of the tested hypothesis in this study at the time of event collection. All analyses in this report are based on intention-to-treat and we further mitigated the possible effect of any attrition bias and reporting bias at individual trial level by collection of additional unpublished data.