| Ripollés-Melchor et al. [30] | 2019 | National multicenter prospective cohort | Adherence rate Q1 (>77.3%) vs. Q2 (>63.6%, <73.7%) vs. Q3 (>54.5%, <63.6%) vs. Q4 (<54.5%) | 521×4 | Colorectal surgery (MIS: 59.21%) | Q1 compared with Q4: moderate to severe complications (OR 0.34, 95% CI 0.25−0.46, P<0.001), overall complications (OR 0.33, 95% CI 0.26−0.43, P<0.001), mortality (OR 0.27, 95% CI 0.07−0.97, P=0.06). | Adherence to 22 ERAS items |
| Catarci et al. [31] | 2020 | Prospective cohort (two centers) | Adherence rate <80% vs. 80%−89% vs. ≥90% | 196 | Minimally invasive colorectal surgery | Overall morbidity (%/10): 5.1 vs. 3.7 vs. 2.9 (P=0.04), major morbidity (%/10): 2.2 vs. 0.3 vs. 0.3 (P=0.0002), anastomotic leakage (%): 14.7 vs. 2.8 vs. 2.5 (P=0.013), median overall LOS (days): 6 vs. 5 vs. 4 (P=0.05) | Mean adherence rate: 85.4%, a significant dose–effect curve for overall and major morbidity rates, anastomotic leakage rates and LOS |
| Milone et al. [32] | 2022 | National multicenter prospective cohort | Single-arm | 1,138 | Minimally invasive colorectal surgery | 100% adherence: 8.9%, 75% adherence: 64.7%, Adherence of >75% was associated with significantly better functional recovery (90.2±98.8 vs 95.9±33.4 h, P=0.003) | Definition of functional recovery: complete mobilization+stool passage +tolerance of a solid diet |
| Pisarska et al. [33] | 2019 | Prospective cohort | Adherence rate <80% vs. ≥80% | 109 vs. 241 | Laparoscopic colorectal cancer resection | <80% compliance with ERAS protocol: a significant factor associated with poor 3-year survival (HR 3.38, 95% CI 2.23–5.21, P=0.0102) | <80% adherence was associated with a longer hospital stay (6 vs. 4 days, P<0.0001), higher rate of postoperative complications (44.7% vs. 23.3%, P<0.0001), poor functional recovery parameters on POD #1: tolerance of oral diet (53.4% vs. 81.5%, P<0.0001) and mobilization (77.7% vs. 96.1%, P<0.0001) |
| Catarci et al. [34] | 2022 | Multicenterprospective cohort | Single-arm | 3,830 | Colorectal surgery(MIS: 79.7%) | Overall or postoperative ERAS adherence higher or lower than the median level was not significant for major morbidity or anastomotic leak | Significant factors for major morbidity: perioperative transfusion (OR 7.79, 95% CI 5.46–11.10; P<0.0001), standard anesthetic protocol (OR 0.68, 95% CI 0.48–0.96; P=0.028) Significant factors for anastomotic leak: male sex (OR 1.48, 95% CI 1.06–2.07; P=0.021), perioperative transfusions (OR 4.29, 95% CI 2.93–6.50; P<0.0001), non-standard resections (OR 1.49, 95% CI 1.01–2.22; P=0.049) |
| Asklid et al. [35] | 2021 | Retrospective cohort (the Swedish part of the international ERAS Interactive Audit System) | 1,900 | Anterior resection | Effect of mean preoperative and intraoperative compliance rate to ERAS on anastomotic leak: OR 0.99, 95% CI 0.97−1.01 | Significant predictors for AL in multivariate analysis: male sex, obesity, peritoneal contamination, year of surgery 2016–2020, age, duration of primary surgery | |