Skip to content

OASI2: Evaluation of strategies for sustainable implementation of the OASI Care Bundle in maternity units

OASI2: a hybrid effectiveness implementation RCT to inform scale up of care bundle to reduce obstetric anal sphincter injury (OASI) caused during childbirth

Status
Active, not recruiting
Phases
Unknown
Study type
Interventional
Source
ISRCTN
Registry ID
ISRCTN26523605
Enrollment
11107
Registered
2021-01-27
Start date
2021-11-27
Completion date
Unknown
Last updated
2026-05-11

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

Conditions

Obstetric anal sphincter injury (OASI) caused during childbirth Pregnancy and Childbirth

Interventions

The OASI Care Bundle has already demonstrated effectiveness in reducing women’s risk of severe perineal tearing in childbirth - all 30 participating units will therefore apply the OASI Care Bundle. Ea

Sponsors

Croydon Health Services NHS Trust
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: There are two groups of participants in this study: midwifery and obstetric clinicians from participating units, who will be asked to incorporate the care bundle into their routine practice, and women giving birth in participating units who may receive the care bundle if eligible. All midwives and obstetricians working at participating units are considered participants in the study. Two clinicians (one midwife and one obstetrician) will be selected by their unit leadership for the role of OASI QI Lead. All clinicians (including OASI QI Leads) will be invited to complete surveys at two points in the implementation period to share their experiences and thoughts about the care bundle and its implementation in their units. Women who attend their antenatal care appointment at participating units are eligible to receive information about OASI and the OASI Care Bundle (discussing the care bundle with women during antenatal care is the first element of the care bundle). Women who subsequently have a singleton, live, term, cephalic, vaginal birth are eligible to receive the care bundle if they are in a birthing position that allows for it and if they provide verbal consent to the elements as they are communicated by the attending clinician, as per routine practice. Eligible women will be recruited to participate in a postnatal survey about their birth experience as it relates to perineal protection/OASI prevention. To be eligible to participate in the survey, women must have had a singleton, live, term, cephalic, vaginal birth in any participating maternity unit.

Exclusion criteria

Exclusion criteria: 1. Clinicians (OASI QI Leads and midwifery/obstetric staff) not employed by one of the 30 participating maternity units 2. Women will not be invited to participate in the postnatal survey if they had a caesarean section or multiple or preterm or breech or stillbirth

Design outcomes

Primary

MeasureTime frame
1. OASI rates (primary clinical outcome) measured using Local Maternity Information Systems and the SMR02/SBR at baseline, months 3, 6, 9 and 12 2. Clinicians’ adoption of the OASI Care bundle (primary implementation outcome) measured using the Normalization Measurement Development (NoMAD) tool at months 4 and 10

Secondary

MeasureTime frame
1. Women’s perceptions of the acceptability of the care bundle, measured using postnatal questionnaire at months 5-8 2. Clinicians’ perceptions of the acceptability, appropriateness and feasibility of the care bundle, measured using Intervention Acceptability Measure (IAM), Appropriateness of Intervention Measure (AIM), Feasibility of Intervention Measure (FIM) at months 4 and 10 3. Facilitators’ perceptions of the acceptability, appropriateness and feasibility of the scale-up strategy, measured using Intervention Acceptability Measure (IAM), Appropriateness of Intervention Measure (AIM), Feasibility of Intervention Measure (FIM), and focus group discussions at months 4 and 10 (IAM, AIM, and FIM), and month 12 (focus groups) 4. Care bundle compliance recorded by clinician at months 3, 6, 9 and 12

Countries

England, Scotland, United Kingdom, Wales

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: May 16, 2026