Core Outcome Measures in Effectiveness Trials

The CO-OPT Study: Core Outcomes in Obstetric Anal Sphincter Injury Prevention and Treatment

General Information

Objective: The objective of this project is to develop a core outcome set for studies investigating interventions for the prevention and treatment of Obstetric Anal Sphincter Injuries (OASIS).

Background: Obstetric Anal Sphincter InjurieS (OASIS) are a severe form of birth related perineal trauma occurring in over 6000 Australian women per year1 with an increasing annual incidence. The impact of such trauma for these women may include severe perineal pain, anal incontinence, urinary retention, sexual dysfunction, and may be complicated by infection, wound breakdown and fistula that may take months or years to treat and resolve with accompanying social, psychological and emotional morbidity.
Many studies of interventions to prevent OASIS or treat the injury to minimise the consequences have been conducted, however a wide range of outcome measures have been used making the generalisability to clinical practice challenging. The development, agreement on and use of an core outcome set for such studies would assist in establishing the evidence base and implementation of effective measures to reduce the minimise of OASIS.

Dr J. Oliver Daly (Principal Investigator) - Western Health, Monash University, University of Melbourne
Prof. Ben Mol - University of Adelaide, Adelaide, Australia
Prof. Rebecca Rogers - University of Texas, USA
Mr Abdul Sultan - Croydon University Hospital, UK
Ms Ranee Thakar - Croydon University Hospital, UK
Ms Sara Webb - Birmingham Women's Hospital, UK

Further Study Information

Current Stage:
March 2017 - July 2018
Funding source(s):
To be confirmed

Health Area

Disease Category
Pregnancy & childbirth

Disease Name
Obstetric Anal Sphincter Injury

Target Population

Age Range
18 - 60


Nature / type of Intervention


Delphi process
Literature review
Systematic review

1. Identification and establishment of stakeholder group representation with development and publication of study protocol.
2. Conduct systematic review of outcome measures used in OASIS prevention and treatment studies to identify reported outcomes.
3. Conduct an international survey of stakeholders to review identified outcomes from step 2, and other outcomes identified by stakeholders, to develop an outcome inventory.
4. Using the Delphi methodology, engaging with the stakeholders to achieve a consensus on elements of the outcome inventory to form the core outcome set
5. Presentation of the results to stakeholders with collation of feedback and submission of final core outcome set for publication, dissemination and implementation.

Stakeholders Involved

Clinical experts
Consumers (patients)
Journal editors
Patient/ support group representatives

Study Type

COS for clinical trials or clinical research
COS for practice

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