Abstract: Ten studies met the inclusion criteria for the review, and nine studies provided information on one or more outcomes for the review. A total of 1014 participants were randomly assigned to the enhanced recovery protocol (499 participants) or standard care (515 participants) in the nine RCTs. Most of the trials included low anaesthetic risk participants with high performance status undergoing different upper gastrointestinal, liver and pancreatic surgeries. Eight trials incorporated more than one element of the enhanced recovery protocol. All of the trials were at high risk of bias. The overall quality of evidence was low or very low. None of the trials reported long-term mortality, medium-term health-related quality of life(three months to one year), time to return to normal activity, or time to return to work. The difference between the enhanced recovery protocol and standard care were imprecise for short-term mortality (enhanced recovery protocol: 4/425 (adjusted proportion = 0.6%); standard care: 1/443 (0.2%); seven trials; 868 participants; RR 2.79; 95% CI 0.44 to 17.73; very low quality evidence), proportion of people with serious adverse events (enhanced recovery protocol: 4/157 (adjusted proportion = 0.6%); standard care: 0/184 (0.0%); two trials; 341 participants; RR 5.57; 95% CI 0.68 to 45.89; very low quality evidence), number of serious adverse events (enhanced recovery protocol: 34/421 (8 per 100 participants); standard care: 46/438 (11 per 100 participants); seven trials; 859 participants; rate ratio 0.72; 95% CI 0.45 to 1.13; very low quality evidence), health-related quality of life (four trials; 373 participants; SMD 0.29; 95% CI -0.04 to 0.62; very low quality evidence) and hospital readmissions (enhanced recovery protocol: 14/355 (adjusted proportion = 3.3%); standard care: 9/378 (2.4%); seven trials; 733 participants; RR 1.4; 95% CI 0.69 to 2.87; very low quality evidence). The enhanced recovery protocol group had a lower proportion of people with mild adverse events (enhanced recovery protocol: 31/254 (adjusted proportion = 10.9%); standard care: 51/271 (18.8%); four trials; 525 participants; RR 0.58; 95% CI 0.39 to 0.85; low quality evidence), fewer number of mild adverse events (enhanced recovery protocol: 69/499 (13 per 100 participants); standard care: 128/515 (25 per 100 participants); nine trials; 1014 participants; rate ratio 0.52; 95% CI 0.39 to 0.70; low quality evidence), shorter length of hospital stay (nine trials; 1014 participants; MD -2.19 days; 95% CI -2.53 to -1.85; low quality evidence) and lower costs (four trials; 282 participants; MD USD -6300; 95% CI -8400 to -4200; low quality evidence) than standard care group. Based on low quality evidence, enhanced recovery protocols may reduce length of hospital stay and costs (primarily because of reduction in hospital stay) in people undergoing major upper gastrointestinal, liver and pancreatic surgeries. However, the validity of the results is uncertain because of the risk of bias in the trials and the way the outcomes were measured. Future RCTs should be conducted with low risk of bias, and measure clinically important outcomes for including the three months to one year period.

Plain-language summary: Ten studies met the inclusion criteria for the review, and nine studies provided information for the review. A total of 1014 participants received an enhanced recovery protocol (499 participants) or standard care (515 participants) in the nine trials. The decision on whether a participant received an enhanced recovery protocol or standard care was made using methods similar to the toss of a coin, ensuring that the participants in the two groups were similar. One additional trial (including 33 participants) also performed the same comparison but did not provide any information for this review. Most of the trials included persons who were healthy in aspects other than the condition requiring surgery. Eight trials incorporated more than one component of the enhanced recovery protocol. None of the trials reported long-term deaths, medium-term health-related quality of life (three months to one year), time to return to normal activity, or time to return to work. The difference between enhanced recovery protocols and standard care was imprecise for short-term deaths, percentage of people with major complications, total number of major complications, health-related quality of life and hospital readmissions. Enhanced recovery protocols had a lower percentage of people with minor complications, fewer minor complications, shorter length of hospital stay (approximately two days shorter hospital stay per person) and lower costs (cost savings of approximately USD 6300 per person) compared to standard care. Because the trials were of poor quality and did not include clinically important end points, future high quality studies are needed in this field. The quality of evidence was low or very low. As a result, there is a lot of uncertainty regarding the results.