Human factors study of a newly approved prefilled syringe of epinephrine for the treatment of anaphylaxis.

BACKGROUND Epinephrine remains the treatment of choice for acute anaphylaxis. However, currently available autoinjectors are costly, and studies have demonstrated human factor issues that result in incorrect use as well as device failures. OBJECTIVE A recent U.S. Food and Drug Administration approved prefilled syringe of epinephrine for the treatment of anaphylaxis was examined in a prospective human factors validation study to determine the likelihood that the product would be used effectively by intended users. METHODS A total of 82 participants were enrolled in this prospective study, including adults with and without epinephrine injector experience, adolescents with and without epinephrine injector experience, and lay caregivers with and without epinephrine injector experience. Half of the participants in each user group were trained to use the newly approved prefilled epinephrine syringe before its first use in the study. Critical tasks that could cause harm and compromise the successful use of epinephrine were assessed and included five categories: (1) open the case, (2) retrieve prefilled syringe, (3) remove needle cap, (4) insert needle in the thigh by using a needle pad, and (5) press plunger until it stops. The participants were scored by an independent observer on the correct use of the device. RESULTS Of the participants, 100% (82/82) completed category 1, 100% of the participants (82/82) completed category 2, 100% (82/82) completed category 3, 93% (71/76) completed category 4 (six participants were observed to have a device with a bent needle and were taken out of the analysis), and 99% (81/82) completed category 5. CONCLUSION In this prospective study of human factors that effect correct epinephrine injection, a high rate of participants successfully completed the tasks when using the prefilled syringe, a newly approved epinephrine syringe for the treatment of anaphylaxis. These results indicated that the newly approved prefilled syringe of epinephrine should provide a user-friendly treatment for acute anaphylaxis.