Because the mothers' income was not listed on the birth records, we were not able to examine directly the effect of income on prenatal care and birth outcomes.
Furthermore, on the basis of the available medical records, we were not able to better classify the symptomology with regards to dyspnea, chest pain, general malaise and fatigue.
From available medical records we were not able to distinguish if mammography detected cases had participated in regular scheduled mammography screening.
Due to missing detailed pedigree records we were not able to identify a possible common ancestor among the disease allele carriers.
Because of our reliance on medical records, we were not able to distinguish between actual watchful waiting and surveillance, the latter being an active management process where "curative" treatment may be applied if progression is noted.
Because we relied on administrative vital statistics records, we were not able to assess whether mothers resided within the air basin throughout their pregnancies, or determine how much time they spent at their primary residence.
Additionally, due to the limitations of pharmacy dispensing records we were not able to confirm the indication for NSAIDs and colchicine dispensed within the 30 days prior to and including the date of the first ULD dispensing.
First, because our outcome measures were derived from medical records, we were not able to address the link between mental health and urbanity-rurality that may exist at the subclinical level, nor could we explore the role of potentially important contextual factors (e.g., social capital).
Because maternal weight, height and parity were not recorded, we were not able to define SGA by customized birth weight standards [ 15].
However, since the exact timing of transfusion is not documented in the TR-DGU, and only the cumulative amount of transfused blood products between the time of ER arrival and ICU admission is recorded, we were not able to adjust for survivorship bias in our logistic regression model as was done by Snyder et al. [ 31].
