Background
Outcome-based quality metrics in surgery have limitations, including susceptibility to gaming and poor generalizability. American College of Surgeons (ACS) verification programs emphasize structural and process standards, but their multidomain impact on care quality has not been comprehensively evaluated.

Study Design
A systematic review and meta-analysis of studies comparing ACS-verified vs nonverified centers or pre- and postverification outcomes was performed. Outcomes were categorized using the STEEEP (Safe, Timely, Effective, Efficient, Equity, Patient-centeredness) framework. Due to heterogeneity, Stouffer’s Z-score method aggregated p values weighted by sample size to assess directional effects, with Holm adjustment for multiple comparisons.

Results
Thirty-one studies encompassing 131 outcomes were included. Overall, 61% of outcomes demonstrated improvement associated with verification, 34% showed no difference, and 5% suggested worse outcomes. Aggregated analysis demonstrated significant improvements in safety (Z = 3.03, p = 0.0024), effectiveness (Z = 11.77, p < 0.0001), equity (Z = 3.29, p = 0.001), and patient-centeredness (Z = 5.36, p < 0.0001). Timeliness showed no significant change (p = 0.3735). Efficiency demonstrated mixed results and was not significant after Holm adjustment (p = 0.0351). Findings reflect directional consistency across heterogeneous settings rather than pooled effect sizes.

Conclusions
ACS verification is associated with consistent improvements in multiple domains of surgical quality, particularly safety and effectiveness. Benefits are not uniform across all domains, with limited evidence for efficiency, timeliness, and equity. These findings support verification as a structural approach to quality improvement while highlighting the need for standardized outcomes and stronger methodological designs.