Table 3.

Principal cohort analysis results (n=24,868)

	Adjusted range	y-intercept (baseline)	Absolute quarterly change (slope)	Relative quarterly change	R2	P value
RBC transfusion in ED	10.5–15.5%	14.2%	−0.1%	−0.7%	0.18	0.0001
Subgroup 1 (Hgb ≤6.9 g/dl)	52.1–70.6%	63.1%	−0.4%	−0.6%	0.13	P<0.0001
Subgroup 2 (Hgb 7.0–9.9 g/dl)	14.3–27.3%	25.4%	−0.4%	−1.6%	0.38	P<0.0001
Subgroup 3 (Hgb ≥ 10.0 g/dl)	0.4–1.8%	1.4%	−0.04%	−4.0%	0.34	P<0.0001
RBC transfusion during index hospitalization	25.1–31.9%	32.8%	−0.4%	−1.1%	0.82	<0.0001
RBC transfusion in 90 days	28.2–35.0%	35.7%	−0.4%	−1.1%	0.85	<0.0001
90-day repeat ED visit	27.9–33.3%	29.5%	+0.06%	+0.2%	0.05	<0.0001
90-day rehospitalization	13.9–18.4%	17.2%	−0.08%	−0.5%	0.11	<0.0001
90-day mortality	0.1–0.9%	0.6%	−0.03%	−4.7%	0.61	<0.0001

Results are presented using the best fit linear line to the plotted data of adjusted outcomes rates (as determined by the respective logistic regression models) and where the adjusted outcome rate = (bx + y) and b = absolute quarterly change (slope), x = quarter (time) and y = intercept (baseline). Relative quarterly changes are calculated by dividing the absolute quarterly change by the extrapolated baseline values (y-intercept).

Abbreviations – ED = emergency department; Hgb = hemoglobin; RBC = red blood cell