Skip to content

International Surgical Outcomes Study (ISOS)

International observational 7-day cohort study of complications following elective surgery

Status
Active, not recruiting
Phases
Unknown
Study type
Observational
Source
ISRCTN
Registry ID
ISRCTN51817007
Enrollment
50000
Registered
2014-01-03
Start date
2014-04-01
Completion date
Unknown
Last updated
2021-07-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Elective surgery Surgery

Interventions

This is an observational study. Patients will be followed up until hospital discharge or for a maximum of 30 days, whichever is shorter.

Sponsors

Queen Mary University of London (UK)
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: All adult patients (aged 18 years or older) undergoing elective surgery in a participating hospital during the seven-day cohort period with a planned overnight stay.

Exclusion criteria

Exclusion criteria: Patients undergoing emergency surgery, planned day-case surgery or radiological procedures

Design outcomes

Primary

MeasureTime frame
To confirm the incidence of 30-day in-hospital complications following elective in-patient surgery.

Secondary

MeasureTime frame
1. In-hospital all-cause mortality (censored at 30 days following surgery) 2. Admission to critical care (within 30 days following surgery) 3. Duration of hospital stay (duration of primary hospital stay after surgery)

Countries

Australia, Austria, Belgium, Brazil, Canada, China, Egypt, Germany, Greece, Hong Kong, India, Indonesia, Iraq, Italy, Malaysia, Mexico, New Zealand, Nigeria, Pakistan, Portugal, Romania, Russian Federation, Singapore, South Africa, Spain, Sweden, Switzerland, United Kingdom, United States of America

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Mar 12, 2026