Janet Smylie expresses ethical and methodological questions about our study.1 In the first instance, it is important to realize that our study did not constitute participatory action research,2 which would indeed require what Smylie suggests in terms of involvement of ethnic groups. Rather, as stated in the Methods section, our study involved a hospital-based cohort of pregnant women and did not initially target any specific ethnic group. Data on ethnic origin, among other variables, were collected as part of the study, and demographic and clinical details have been published elsewhere.3The decision to prepare the CMAJ paper for publication arose from our analysis of the data, during which we found important differences between ethnic groups that we thought should be reported because of their public health implications.
Smylie also raises some methodologic concerns. We are unsure what is meant by her reference to “methodologic problems with the way in which ethnicity was determined,” since no details are given about where we might have erred. We used standard questions and classified ethnicity according to current standards. Smylie is concerned about the exclusion of “multiple-ethnicity responses, such as Caucasian and First Nations.” Only 3 First Nations and 3 Métis women also checked off Caucasian ethnicity, and these people were not coded as Caucasian because the categories were mutually exclusive for analytical purposes. In our initial analysis we separated out various ethnic groups, but during the peer review and revision process we were asked to present pooled results for our Table 1 and for the final logistic regression. Nevertheless, we did specifically discuss differences between ethnic groups in our Results section. With regard to potential underpowering, we acknowledged small numbers as a limitation of the study and understand that there may have been a lack of power to detect other potential differences.
We believe it is both scientifically and ethically sound to view this study as having the potential to improve the lives of people who have suffered and continue to suffer health disparities.