Cohort Definition Name: Non-Emergent Major Non-Cardiac Surgery
Contributor Name: Evan Minty, Surgery and Perioperative WG
Contributor OrcID : 0000-0003-4631-9992
Logic Description : Cohort entry indexed on procedure occurrence of a ‘major non cardiac surgery’ (earliest event) with the following additional inclusion criteria:
• Age > 18
• Inpatient visit on day of surgery, and day after surgery, and no ED visit on, or in the 48h prior to surgery (i.e. non emergent surgery, requiring overnight stay in hospital).
• Observation period requirement of 365d
• Cohort exit: end of observation.
Recommended Study Application: Target
Assertion Statement: This cohort definition was executed on at least one real person-level observational health data source and resulted in a cohort with at least 1 person.
Submitted Cohort Definition:
MNCS.txt (443.2 KB)
Target Clinical Description (& Background)
Non-emergent major non-cardiac surgery refers to ‘major’ surgical procedures that are scheduled in advance and do not involve the heart or its major vessels. These set of surgeries of interest are, planned, to and allow for appropriate pre-operative evaluation, preparation, and coordination. A focus of that perioperative evaluation is the management of cardiac risk. This leads to the focus on non cardiac surgeries (cardiac surgeries carry very different cardiac risks). ‘Major’ surgeries have typically been defined as those that generate enough physiologic disturbance to require at least an overnight stay in the hospital.
A group of OHDSI collaborators participated in defining a set of surgical concepts that were felt to represent MNCS as part of the PROTEUS study-thon coordinated by Tufts University. We took an approach of specifying MNCS by referencing the enrolment criteria in a large prospective trial in perioperative medicine .
The inclusion criteria of that trial specified the following surgeries / groups of surgeries:
Major orthopedic surgery – A patient undergoing one or more of the following orthopedic surgeries: major hip or pelvis surgery, internal fixation of femur, knee arthroplasty, above knee amputations, or lower leg amputation (amputation below knee but above foot).
Major general surgery : complex visceral resection, partial or total colectomy or stomach surgery, other intra-abdominal surgery, or major head and neck resection for non-thyroid tumor.
Major urology or gynecology surgery – nephrectomy, ureterectomy, bladder resection, retroperitoneal tumor resection, exenteration, cytoreduction surgery, hysterectomy, radical prostatectomy, or transurethral prostatectomy.
Major neurosurgery craniotomy or major spine surgery (i.e., surgery involving multiple levels of the spine).
Major vascular surgery – thoracic aorta reconstructive vascular surgery, aorto-iliac reconstructive vascular surgery, peripheral vascular reconstruction without aortic cross-clamping, extracranial cerebrovascular surgery, or endovascular abdominal aortic aneurysm repair.
Major thoracic surgery –pneumonectomy, lobectomy, wedge resection of lung, resection of mediastinal tumor, or major chest wall resection.
The groups of surgeries that appeared to meet the inclusion criteria for that study were specified (as standard OHDSI vocabulary concepts) in ATLAS. This cohort definition then underwent design diagnostics (PHOEBE), and one round of cohort diagnostics. These and additional characterization exercises informed additional iteration of this cohort.
To adjudicate a procedure as being ‘major’ or ‘minor’, we derived the following criteria, based on those abstracted from a literature review (with a focus on defining major surgery for hemophilia management ), and from veterinary literature [3,4]:
- Minor surgeries:
- a. Only skin and /or mucous membranes and / or superficial connective tissue is resected.
- b. Biopsies or drainage procedures using a needle or trocar
- c. Typically don’t require general or spinal anesthetic or consideration of invasive respiratory support. May include procedures carried out with conscious sedation.
- Major surgeries:
- a. Any procedures that involve the penetration of a major body cavity and associated mesenchymal barrier (e.g. pleural cavity, peritoneum, meninges) for purposes other than needle / trocar biopsy or drainage of fluid.
- b. Orthopedic procedures not classified as minor.
- c. Normal anatomy is typically altered (or restored) by the procedure.
- d. Typically require a general or spinal anesthetic (or more specialized nerve blocks).
Evaluation Conclusion : Procedural terminologies, their mappings, and their parent child relationships make delineation of ‘major’ surgeries a challenge. This cohort underwent further refinement to remove additional ‘low risk’ procedures via manual inspection (EM). Further characterization of this version of the cohort is recommended. In addition, there will certainly be errors of omission (i.e. other ‘major’ surgeries that could have been included). Nonetheless it is felt to represent one of the more comprehensive specifications of ‘major non cardiac surgery’ available to the research community.
 Writing Committee for the VISION Study Investigators. Association of Postoperative High-Sensitivity Troponin Levels With Myocardial Injury and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery. JAMA. 2017 Apr 25;317(16):1642–51.
 Solimeno LP, Escobar MA, Krassova S, Seremetis S. Major and Minor Classifications for Surgery in People With Hemophilia: A Literature Review. Clin Appl Thromb Hemost. 2018 May 1;24(4):549–59.
 Guide for the Care and Use of Laboratory Animals - NCBI Bookshelf [Internet]. [cited 2023 Jan 16]. Available from: Guide for the Care and Use of Laboratory Animals - NCBI Bookshelf
 Brown MJ, Pearson PT, Tomson FN. Guidelines for animal surgery in research and teaching. AVMA Panel on Animal Surgery in Research and Teaching, and the ASLAP (American Society of Laboratory Animal Practitioners). Am J Vet Res. 1993 Sep;54(9):1544–59.