Table 2. Errors discovered AFTER (n=466) blood transfusion by type of hospitals, TESS¹ 2008 – 2011.

Type of Transfusion error	Small (less than 2,000 transfusions per year)		Medium (2,000 to 10,000 transfusions per year)		Large (more than 10,000 transfusions per year)		Overall
	Freq.	Rate	Freq.	Rate	Freq.	Rate	Freq.	Rate
Distributor codes	0	-	2	1:117,432	0	-	2	1:439,663
Product check-in	0	-	0	-	3	1:206,374	3	1:293,109
Unit storage	0	-	0	-	1	1:619,123	1	1:879,326
Inventory management	2	1:12,670	3	1:78,288	2	1:309,562	7	1:125,618
Product request	3	1:6,642	5	1:47,934	56	1:11,103	64	1:13,771
Request for pick-up	0	-	0	-	1	1:621,772	1	1:881,366
Product selection	0	-	3	1:94,614	10	1:65,484	13	1:73,786
Unit manipulation	0	-	4	1:70,961	2	1:327,418	6	1:159,870
Unit issue	2	1:9,264	11	1:21,308	30	1:20,224	43	1:19,991
Unit transfusion	4	1:4,632	192	1:1,221	82	1:7,399	278	1:3,092
Sample handling	0	-	0	-	7	1:52,289	7	1:89,415
Sample receipt	0	-	4	1:51,917	18	1:20,335	22	1:28,450
Sample testing	0	-	3	1:112,172	14	1:58,353	17	1:70,731
Miscellaneous	0	-	0	N/A	2	N/A	2	N/A
Total	11	N/A	227	N/A	228	N/A	466	N/A

¹TESS= Transfusion Error Surveillance System