Human factors study of ZENEO® (needle-free autoinjector) and comparison of different user instruction formats

ZENEO® (Crossject, Dijon France) is a novel prefilled, disposable needle-free auto-injector (AI) device under development for drug deliverer in a variety of routine-use or emergency situations. At present, reported user experience and patient preferences are limited. To determine what impact different forms of user instructions may have on successful use of the ZENEO® device.

We conducted a human factors study on 134 healthy volunteers. On enrolment, subjects were provided with different instructive training material; a device quick guide plus either use of a dummy training device, an illustrated leaflet, or a demonstration video. After 6 weeks, subjects returned and performed an unaided simulated injection, and compliance with specific steps necessary for successful use, and avoidance of actions that interfere with appropriate use was recorded by an investigator.

Most subjects (93.3%) successfully performed a simulated injection without major errors (regardless of type of educational instructions), and the great majority (97.5%) reported no difficulty in a range of objective measures of important necessary steps. Compliance with necessary steps and avoidance of detrimental actions was greater in those subjects with prior access to a demonstration video or provided with an illustrated patient leaflet. Prior experience with a dummy training device provided little if any benefit. User satisfaction with the device was high.

The results show that the ZENEO® device can be effectively used with a conventional suite of printed user instructions. Use of a demonstration video provides additional value, whereas use of a dummy training device had limited value.