TABLE 2.

Percent difference in allogeneic RBC units transfused in 2015 and 2017 from matched hospitals

Inpatient surgical volume category	N*	Median (mean) 2017 allogeneic RBCs*	Median % difference†	IQR‡ of % difference†
100–999 surgeries per year	140	400 (564)	−9.1%	26.5%
1,000–1,399 surgeries per year	224	1,285 (1,493)	−10.2%	19.7%
1,400–2,399 surgeries per year	339	1,952 (2,209)	−9.1%	21.8%
2,400–4,999 surgeries per year	454	3,548 (3,928)	−6.5%	19.1%
5,000–7,999 surgeries per year	190	6,209 (6,884)	−3.6%	17.2%
8,000 or more surgeries per year	144	13,662 (15,398)	1.0%	14.8%
Total	1491	2,788 (4,340)	−6.5%	21.1%

^*Based on matched facilities reporting allogeneic RBCs in both 2015 and 2017 NBCUS surveys.

^†% difference calculated as 100*(2017–2015)/2015.

^‡Interquartile range (75th-25th percentile).