Core Outcome Measures in Effectiveness Trials

The Composite Adverse Obstetric Outcomes Study (CAOOS)

General Information

Perinatology involves two individuals, the mother and the fetus that are intricately related. In Trials in perinatology, trials often use 'composite' maternal and fetal/neonatal outcomes to reflect that include health outcomes such as mortality and serious morbidity. However, there is no standardization with regard to the what outcomes to be considered within should constitute this composite or the manner in which they should be defined/ measured. The involvement of pregnant women and other stakeholders in deciding which individual maternal and fetal outcomes are important enough to constitute composite pregnancy outcomes is also limited. This core outcome set hopes to standardize maternal and perinatal outcomes for all future trials in perinatology.
Numerous clinical trials exist to improve outcomes, however, these studies are limited in their translation to clinical care due to variable outcome reporting that omits the patient perspective. Outcome standardization addresses irrelevancy of outcomes, researcher bias and study incomparability, and can thus improve research quality and subsequent application to clinical practice. These gaps could be is may be achieved and addressed via the development of a Core Outcome Set for Composite Obstetric Outcomes that involves pregnant women, their partners and family members, as well as the other relevant stakeholder groups, as per the framework outlined by the COMET handbook. The following objectives: The Core Obstetric Outcomes Study (COOS) will comprise five steps:
I. Identifying reported outcomes and definitions in through a systematic review of the literature thus far;
II. Determining what outcomes are important to pregnant women and other stakeholders, including patients; through interviews and focus groups
III. Achieving consensus on a list of outcomes through an online Delphi survey
IV. Finalizing the components of the composite through a face-to-face consensus meeting and Determining how to define/measure the components of the composite.

Mount Sinai Hospital
University of Toronto
Principal Investigator: Dr. Rohan D’Souza

Further Study Information

Current Stage:
June 2018 - May 2020
Funding source(s):

Health Area

Disease Category
Pregnancy & childbirth

Disease Name

Target Population

Age Range
16 - 50


Nature / type of Intervention


Consensus meeting
Delphi process
Focus group(s)
Literature review
Systematic review

Our methodology to choose the COOS, entails a systematic review of clinical trials and systematic reviews of all study types, a literature review of qualitative studies, a qualitative stage (focus groups and individual interviews) and finally, the Delphi methodology followed by a face-to-face consensus meeting. To arrive at the most appropriate measurements per outcome in the core set, we will evaluate using COSMIN and the Delphi methodology.

Stakeholders Involved

Clinical experts
Conference participants
Consumers (caregivers)
Consumers (patients)
Policy makers
Service providers
Service users

Study Type

COS for clinical trials or clinical research
Recommended outcome measures (measurement)

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