Table 1.

Description of factors and number of survey items per factor

Factor	Description of what each factor/dimension represents	# of Survey items loaded into factor*
1	Perceived alert noise or overload (too many unnecessary alerts)	6
2	Perceived effectiveness of alert systems (alert system increases productivity/ effectiveness of system)	4
3	Patient notification support (have staff help/ helpful system support)	3
4	Experience (demographic characteristics)	3
5	Outcomes of Patient Safety (missing alerts leading to poor patient care/ witnessing others missing alerts)	2
6	Volume of Alerts (number of alerts received per day)	3

*Note: see Appendix I for survey items loaded into each factor.