Statistical analysis

Patients were grouped by birth location (community hospital vs tertiary care center), and statistical differences were determined for several clinical characteristics. Student’s t tests were used for normally distributed continuous variables, and Wilcoxon rank-sum tests were used for non-normally distributed variables. Normality was determined by visualizing histograms and Shapiro tests. Chi-squared tests were used for categorical variables, unless expected cell counts were less than 5, in which case Fisher’s exact tests were used. All analyses were performed in R 3.6.2.