CESOR
Center for Emergency Surgery Outcomes Research
Center for Emergency Surgery Outcomes Research
Prospective emergency surgery research organized for target trial emulation.
CESOR is an emergency surgery outcomes research laboratory directed by Gary A. Bass. Its work centers on prospective multicenter platforms, target trial emulation, and standardized data structures for reproducible observational and causal analysis.
Identity
CESOR is organized through defined platforms, methods, outputs, and participation pathways.
CESOR develops prospective multicenter platforms in acute surgical disease and uses target trial emulation when causal questions can be specified explicitly within observed care. Platforms, methods, outputs, and governance follow a standardized structure to preserve interpretability and update control.
Featured studies
SnapChole. International prospective platform study of management strategies and outcomes in acute calculous cholecystitis, with nested target trial emulations in severe disease.
ClinicalTrials.gov registration: NCT07568080.
The dedicated study page provides protocol-facing detail for collaborators and participating centers.
SnapNSTI. International prospective cohort study of necrotizing soft tissue infection focused on debridement timing, antimicrobial strategy, adjunctive therapies, and 90-day outcomes.
ClinicalTrials.gov registration: NCT07107555.
The dedicated study page provides protocol-facing detail for collaborators and participating centers.
IMPEL. International prospective snapshot audit of mechanical large-bowel obstruction focused on diagnostic pathways, strategy selection, operative detail, and medium-term stoma outcomes.
ClinicalTrials.gov registration: NCT07458867.
The dedicated study page provides protocol-facing detail for collaborators and participating centers.
Active platforms
Program structure
Snapshot Platforms
Prospective multicenter cohort structures that characterize presentation, management, and outcomes in acute surgical disease.
Target Trial Emulation
Embedded causal analyses defined by eligibility, time zero, treatment strategies, follow-up, and estimands.
Implementation and Systems Research
Studies of readiness, adoption, workflow, and barriers to evidence uptake in acute care environments.
Data Infrastructure
Standardized data capture, governance, and modular reporting aligned to protocols and outputs.
Methods
CESOR uses target trial emulation when treatment strategies, eligibility, time zero, follow-up, and estimands can be specified explicitly within observed care pathways. This avoids retrospective comparisons built on ambiguous treatment assignment.
Prospective platform design preserves the variable architecture required for causal analysis, including timestamps, pathway assignment logic, and downstream outcome ascertainment.
Director
Gary A. Bass, MD, MSc, MBA, PhD, FEBS (Emergency Surgery)
Assistant Professor of Surgery and Assistant Professor of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania
Gary A. Bass directs CESOR and leads its work in emergency surgery outcomes research, multicenter platform design, causal inference, and implementation-focused study development.