Data Analysis
Descriptive statistics were conducted for the sample overall and by
hospital, with mean and standard deviation (SD) being reported for age
and frequencies and percentages being reported for all other patient
characteristics, which were categorical. Hospitals were compared via an
ANOVA test for age and chi-square tests for all other variables when the
sample size was sufficient. The primary outcome of D2B time, as well as
secondary outcomes of time of ED arrival to first ECG, time from last
ECG to activation, and time from activation to transport to the CCL was
examined with medians and interquartile ranges (IQR) and compared across
hospitals via Kruskal-Wallis tests. Percent of patients who met the
guidelines of first ECG in < 10 minutes and of D2B time
in < 90 minutes was calculated overall and by hospital
and compared via chi-square tests. Also, a binominal test compared the
overall percentage of patients with D2B times ≤90 minutes to the
American Heart Association minimal adherence score of
75%.3
Predictors for D2B times were identified via multivariate linear
regression. Each characteristic was analyzed in an unadjusted model
predicting D2B time then included in one or both of two adjusted models.
Both models contain age, gender, mode of arrival (walk-in versus not),
scenario of arrival, day of the week, patient confounder (yes/no), and
non-patient confounder (yes/no). One model then contained indicators for
the individual hospitals while the other contained the number of steps
from the ED to the CCL. All analysis was conducted in IBM SPSS at a
significance level of 0.05.30