Table 2-B: Quality of Evidence of Studies on the Effectiveness of Bispectral Index Monitors in Reducing Recovery Time.

Study Design	Level of Evidence	No. Eligible Studies
Large RCT,* systematic reviews of RCTs	1	10
Large RCT unpublished but reported to an international scientific meeting	1(g)†
Small RCT	2	1
Small RCT unpublished but reported to an international scientific meeting	2(g)
Non-RCT with contemporaneous controls	3a
Non-RCT with historical controls	3b	1
Non–RCT unpublished but reported to an international scientific meeting	3g
Surveillance (database or register)	4a
Case series (multisite)	4b
Case series (single site)	4c
Case series unpublished but reported to an international scientific meeting	4(g)
Total		12

^*RCT indicates randomized controlled trial.

^†indicates “grey literature” (preliminary reports of studies reported to international scientific meetings).