Table 2.

Potential use errors for the naloxone auto-injector identified as a part of Human Factors Engineering and risk analyses

Severity	Potential Use Errors
Minor	User could misplace instructions, trainer device, or forget key steps
	User drops device before or while removing the outer case
	User does not understand how to open the package or has difficulty removing the packaging
	User fails to hold the injector in place for the full five seconds
	User ignores the instructional leaflet and uses the device anyway (untrained user)
	User ignores the instructions on the device itself (untrained user)
	User removes the safety guard prematurely and then tries to replace it
Moderate	User moves device during the injection, leading to possibility of ineffective dose
	User misplaces the device or cannot find it readily
	User has difficulty pulling off the safety guard
	User does not apply sufficient force initially to activate the injection then eventually determines force required
	User has difficulty removing the device from the outer case
	User attempts to disassemble the device, causing the possibility of premature activation which might result in unintentional self-injection
	User removes the safety guard and then drops the device, causing the potential for premature activation
Critical	User employs the device but the drug is expired or degraded
	User attempts to use a previously used device
	User does not remove the red safety guard
	User pulls the device away from the outer thigh prematurely or fails to hold the injector in place for at least 0.5 s
	User decides not to give the injection
	User places the device in the wrong location (not on the outer thigh or an appropriate muscle)
	User does not place the base on the outer thigh or appropriate alternate location
	User never applies sufficient force to activate the injection
	User puts hand over the wrong end, possibly resulting in accidental self-injection
	User pushes the base with fingers causing premature activation
	User uses the training device on the patient instead of the actual device containing drug