Enhanced recovery strategies in colorectal surgery: is the compliance with the whole program required to achieve the target?

PURPOSE: The complexity of "fast track" (FT) surgery might decrease its applicability in daily practice and extensive diffusion. The aim of this study was to understand if the positive effect of FT on the outcome might be affected by the number, type, level of evidence of the components, or their possible combinations. METHODS: We performed a Medline, Embase, Pubmed, and Cochrane Library literature search of randomized and non-randomized trials comparing FT to conventional care (CC) in elective colorectal operations. By a meta-analytic approach, the effect of FT was estimated by the risk ratio (RR) with a 95 % confidence interval (CI) for the risk of post-operative complications. RESULTS: The analysis included 53 studies (36 non-RCTs with and 17 RCTs), with 4,100 patients in the FT group and 4,424 patients in the CC group for a total of 8,524 patients. Fifty-six different item combinations were observed. The median rate of strategy implementation was 50 %. The positive effect of FT over CC was observed regardless the number (<10 vs. ≥10) of strategies used (RR = 0.80; 95 % CI 0.66-0.98 and RR = 0.75; 95 % CI 0.65-0.87, respectively), the application of items with strong vs. low level evidence (RR = 0.78; 95 % CI 0.67-0.90 and RR = 0.76; 95 % CI 0.63-0.92, respectively), or the frequency (≥80 vs. <80 %) of items implemented (RR = 0.80; 95 % CI 0.69-0.93 and RR = 0.73; 95 % CI 0.61-0.87, respectively). CONCLUSION: The positive effects of FT seem to be achieved regardless the multiplicity and variance of item grouping.