The Ontario Mother and Infant Study (TOMIS) III: A multi-site cohort study of the impact of delivery method on health, service use, and costs of care in the first postpartum year

BACKGROUND: The caesarean section rate continues to rise globally. A caesarean section is inarguably the preferred method of delivery when there is good evidence that a vaginal delivery may unduly risk the health of a woman or her infant. Any decisions about delivery method in the absence of clear medical indication should be based on knowledge of outcomes associated with different childbirth methods. However, there is lack of sold evidence of the short-term and long-term risks and benefits of a planned caesarean delivery compared to a planned vaginal delivery. It also is important to consider the economic aspects of caesarean sections, but very little attention has been given to health care system costs that take into account services used by women for themselves and their infants following hospital discharge. METHODS AND DESIGN: The Ontario Mother and Infant Study III is a prospective cohort study to examine relationships between method of delivery and maternal and infant health, service utilization, and cost of care at three time points during the year following postpartum hospital discharge. Over 2500 women were recruited from 11 hospitals across the province of Ontario, Canada, with data collection occurring between April 2006 and October 2008. Participants completed a self-report questionnaire in hospital and structured telephone interviews at 6 weeks, 6 months, and 12 months after discharge. Data will be analyzed using generalized estimating equation, a special generalized linear models technique. A qualitative descriptive component supplements the survey approach, with the goal of assisting in interpretation of data and providing explanations for trends in the findings. DISCUSSION: The findings can be incorporated into patient counselling and discussions about the advantages and disadvantages of different delivery methods, potentially leading to changes in preferences and practices. In addition, the findings will be useful to hospital- and community-based postpartum care providers, managers, and administrators in guiding risk assessment and early intervention strategies. Finally, the research findings can provide the basis for policy modification and implementation strategies to improve outcomes and reduce costs of care.