Strengths and Limitations
This is a robust population-based study, evaluating a large sample of
patients and a broad spectrum of socio-demographic, clinical and
pathological information through administrative databases that have been
previously validated for healthcare research. The focus on endometrial
cancer in a public healthcare system mitigates some common confounders
in population studies on cancer care disparities. Finally, the use of
validated Canadian measures of marginalization 35provides a unique opportunity to evaluate associations between
inherently complex social, educational, financial and cultural barriers
and cancer outcomes.
However, there are limitations to this study design which should be
acknowledged. Many exposure variables, including marginalization
indices, are based on neighborhood or community characteristics, which
may create misclassification bias when assessing individual patients.
Moreover, stage information and Charlson scores were missing in a large
proportion of the women, though missing information was evenly
distributed between marginalization quintiles. We were not able to
conduct an analysis of recurrence rates and cancer-specific survival
because recurrence are not captured in the Ontario cancer registry and
because secondary causes of death are not reliably documented in death
certificates. Although overall survival is considered an important and
reproducible outcome in oncology, competing causes of death may confound
the interpretation of this endpoint, especially in the endometrial
cancer patient population 48,49. Lastly, the
association between marginalization and survival is confounded by other
factors associated with SDH, including adverse health behaviors, stress,
and chronic diseases and their sequelae, which we were not able to
control for.