An economic evaluation of the Enhanced Recovery After Surgery (ERAS) multisite implementation program for colorectal surgery in Alberta

Abstract

Background: In February 2013, Alberta Health Services established an Enhanced Recovery After Surgery (ERAS) implementation program for adopting the ERAS Society colorectal guidelines into 6 sites (initial phase) that perform more than 75% of all colorectal surgeries in the province. We conducted an economic evaluation of this initiative to not only determine its cost-effectiveness, but also to inform strategy for the spread and scale of ERAS to other surgical protocols and sites.

Methods: We assessed the impact of ERAS on patients’ health services utilization (HSU; length of stay [LOS], readmissions, emergency department visits, general practitioner and specialist visits) within 30 days of discharge by comparing pre- and post-ERAS groups using multilevel negative binomial regressions. We estimated the net health care costs/savings and the return on investment (ROI) associated with those impacts for post-ERAS patients using a decision analytic modelling technique.

Results: We included 331 pre- and 1295 post-ERAS patients in our analyses. ERAS was associated with a reduction in all HSU outcomes except visits to specialists. However, only the reduction in primary LOS was significant. The net health system savings were estimated at $2 290 000 (range $1 191 000–$3 391 000), or $1768 (range $920–$2619) per patient. The probability for the program to be cost-saving was 73%–83%. In terms of ROI, every $1 invested in ERAS would bring $3.8 (range $2.4–$5.1) in return.

Conclusion: The initial phase of ERAS implementation for colorectal surgery in Alberta is cost-saving. The total savings has the potential to be more substantial when ERAS is spread for other surgical protocols and across additional sites.

Fig. 1

Decision tree to estimate health system savings. Savings1 = (LOS1 – LOS1 × IRR1) × c1, where LOS1 is primary LOS of pre-ERAS patients, IRR1 is the impact of ERAS on primary LOS measured by an IRR, and c1 is the marginal cost per hospital day of the primary LOS shortened by ERAS. Savings2 = (LOS2 – LOS2 × IRR2) × c2, where LOS2 is readmission LOS of pre-ERAS patients, IRR2 is the impact of ERAS on readmission LOS measured by an IRR and c2 is the marginal cost per hospital day of the readmission LOS shortened by ERAS. Savings3 = (ED – ED × IRR3) × c3, where ED is the number of ED visits of pre-ERAS patients, IRR3 is the impact of ERAS on ED visits measured by an IRR and c3 is cost per ED visit. Savings4 = (readmit – readmit × IRR4) × LOS2 × c4, where readmit is the number of readmissions of pre-ERAS patients, IRR4 is the impact of ERAS on readmissions measured by an IRR, LOS2 is readmission LOS of pre-ERAS patients, and c4 is the average cost per hospital day of readmissions prevented by ERAS. Savings5 = (SP – SP × IRR5) × c5, where SP is the number of specialist visits of pre-ERAS patients, IRR5 is the impact of ERAS on specialist visits measured by an IRR and c5 is the cost per specialist visit. Saving6 = (GP – GP × IRR6) × c6, where GP is the number of GP visits of pre-ERAS patients, IRR6 is the impact of ERAS on GP visits measured by an IRR and c6 is the cost per GP visit. ED = emergency department; ERAS = enhanced recovery after surgery; GP = general practitioner; IRR = incidence rate ratio; LOS = length of stay; SP = specialist.

Fig. 2

Probability of Enhanced Recovery After Surgery (ERAS) to be cost saving.