CanOSS National Feasibility Study
Building the Foundation for a Canada-Wide Severe Maternal Morbidity (SMM) Surveillance System
To improve maternal health outcomes, we must first understand the factors that contribute to severe maternal morbidity (SMM). The CanOSS National Feasibility Study explored whether birthing units across Canada are equipped to collect standardized, high-quality data on the modifiable factors that drive SMM – and whether they would be willing to contribute that data to a national system.
To assess this, we conducted a cross-country research study using an OSS (Obstetric Surveillance System) model. A structured survey was distributed to leads of Canadian birthing units across all provinces and territories. It included both multiple-choice and open-ended questions, and was administered using REDCap.
Quantitative responses were analyzed using descriptive statistics. Qualitative responses were coded and evaluated using content analysis. We also calculated pooled participation rates with 95% confidence intervals across different tiers of hospital service using Freeman-Tukey transformations and common-effect models.
Key findings
Widespread Engagement: A majority of Canada’s 289 birthing units participated.
Existing Review Systems: Most reported existing internal processes for reviewing SMM, usually on an as-needed basis.
Gaps in Representation: Multidisciplinary review panels often lacked key contributors such as Obstetric Anaesthesia, Midwifery, and Internal Medicine.
Limited Knowledge Sharing: Lessons from reviews were rarely disseminated beyond the hospital and never beyond the regional level.
Strong Willingness to Collaborate: Most respondents expressed readiness to contribute anonymized SMM data to a centralized reporting system.
The findings demonstrate that most Canadian birthing units already have infrastructure to review SMM and are willing to participate in a national, anonymized data-sharing initiative. This confirms the feasibility of launching a pan-Canadian obstetric surveillance system – a critical step toward standardizing maternal health data, identifying preventable complications, and improving care across the country.
Study Protocol:
D’Souza, R., Seymour, R. J., Knight, M., Dzakpasu, S., Joseph, K. S., Thorne, S., Ospina, M. B., Barrett, J., Cook, J., Fell, D. B., Scott, H., Metcalfe, A., van den Akker, T., Lapinsky, S., Skeith, L., Murray-Davis, B., Shah, P., Forte, M., Ashraf, R., Chundamala, J., … Malhamé, I. (2022). Feasibility of establishing a Canadian Obstetric Survey System (CanOSS) for severe maternal morbidity: a study protocol. BMJ open, 12(3), e061093. https://doi.org/10.1136/bmjopen-2022-061093
Published Commentary:
Malhamé, Knight, M., & D’Souza, R. (2022). Initial Steps in Developing and Implementing a Canadian Obstetric Survey System (CanOSS) for Severe Maternal Morbidity. Journal of Obstetrics and Gynaecology Canada: JOGC, 44(6), 637–638. https://doi.org/10.1016/j.jogc.2022.02.002
Malhamé, Knight, M., & D’Souza, R. (2022). Prémices de la conception et mise en œuvre d’un système d’enquête canadien en obstétrique sur la morbidité maternelle grave. Journal D’obstétrique et Gynécologie Du Canada: JOGC., 44(6), 639–640. https://doi.org/10.1016/j.jogc.2022.04.001