Outcomes of Cesarean Section vs Vaginal Delivery: Instrumental Variable Adjusted Analysis

Substantial Variability Between Traditional and Instrumental Variable Estimates of the Risk of Caesarean Section in Canada: a Population-based Cohort Study

This study will examine the effect of cesarean section on perinatal mortality, using data provided by the Canadian Institute for Health Information.

Study Overview

• Status: Completed
• Conditions: Pregnancy Complications; Cesarean Section
• Intervention / Treatment: Procedure: Cesarean Section

Detailed Description

This study will examine administrative data provided by the Canadian Institute for Health Information (CIHI). Maternal obstetrical delivery and neonatal hospitalization records provided by CIHI will be linked before analysis. The primary outcome is in-hospital perinatal mortality. The data will be analyzed by traditional multi-variate logistic regression, and the results from this analysis will be compared to the results from instrumental variable adjusted regression using the Generalized Method of Moments. The instrumental variable is the rate of cesarean delivery among women living within the same hospital catchment area. All analyses will be adjusted for maternal, infant, delivery provider, and hospital factors, as well as for clustering at the level of the delivery hospital.

• Study Type: Observational
• Enrollment (Actual): 1703590

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

All obstetrical deliveries in Canada (except the province of Quebec) between April 1, 2006 and March 31, 2009

Description

Inclusion Criteria:

• Mothers living in Canada and their infants delivering within the study period at Canadian hospitals outside of the province of Quebec.

Exclusion Criteria:

• Maternal record not linkable to neonatal record.
• Multiple gestation.
• Birthweight < 500 gm.
• Gestational age at delivery < 20 weeks.
• Deliveries at hospitals with less than 20 cesarean deliveries during study period.
• Records with missing data for important covariates

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cesarean; Mothers delivered by cesarean section	Procedure: Cesarean Section
Vaginal; Mothers delivered by vaginal delivery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perinatal Mortality	Includes deaths at any age if infant continuously hospitalized (including transfers) in an acute care facility. Includes deaths up to 7 days of age if infant discharged from hospital then readmitted prior to 7 days of age.	up to 7 days

Collaborators and Investigators

• Sponsor: Memorial University of Newfoundland
• Collaborators: Medical Research Foundation - Memorial University
• Investigators: Principal Investigator: Kris Aubrey-Bassler, MD, Memorial University

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): July 1, 2013
• Study Completion (Actual): July 1, 2015

Study Registration Dates

• First Submitted: August 4, 2016
• First Submitted That Met QC Criteria: August 12, 2016
• First Posted (Estimate): August 15, 2016

Study Record Updates

• Last Update Posted (Estimate): August 15, 2016
• Last Update Submitted That Met QC Criteria: August 12, 2016
• Last Verified: August 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pregnancy Complications
• Other Study ID Numbers: MRFCoxAwardAubrey2

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The data provider does not allow sharing of investigator data, but data can be requested directly from them.