RESUMO
PURPOSE: This study evaluated the human factors affecting the ease of use of a disposable autoinjector developed for subcutaneous self-injections performed by patients with chronic diseases. MATERIALS AND METHODS: This was a randomized, single-center study conducted with 65 patients with rheumatoid arthritis. Patients performed six simulated injections. Assessments of patient device acceptance and device usability were made by patient reports and independent observations of compliance with the device instruction for use (IFU) following single injections and repeated injections. RESULTS: A total of 390 simulated injections were performed. Patient device acceptance was high; more than 90% of patients found each of the tested criteria to be acceptable (>80% was required for statistical significance; P<0.016). Perceived ease of use and simplicity of the three-step process resulted in high acceptance scores: mean scores (± standard deviation) were 8.71 (±1.18) and 8.05 (±0.37), respectively, on a 0-10-point scale. Patients also expressed their acceptance with the ease and usefulness of the detection of the remaining drug in the autoinjector. In addition, 80% of patients declared that they would recommend the device to someone else. Globally, the human factors tested (age, sex, hand disability [Cochin score], extent of previous experience with self-injection [ie, expert or naïve]) had no impact on IFU device compliance. In particular, the lack of a Cochin score interaction indicated that the degree of hand disability is not a predictive factor of poor self-injection capability with this autoinjector. CONCLUSION: This study demonstrated a high level of patient acceptance for self-injection with this autoinjector among patients with rheumatoid arthritis. In particular, patients with severe hand disability were able to successfully comply with device IFU.
RESUMO
OBJECTIVE: A disposable autoinjector was developed for subcutaneous (SC) self-injection by patients with chronic diseases. To verify its performance and evaluate its acceptance, a clinical study was conducted in healthy volunteers, comparing SC injections performed by subjects using the autoinjector with SC injections performed by nurses using a syringe. METHODS: This was a randomized, single-center, crossover study comparing SC self-injection using an autoinjector with SC nurse-administered injection using a syringe. Two volumes (0.2 mL and 1 mL) were injected into healthy volunteers. Study objectives included assessment of the accuracy and consistency of the volume injected by the injection systems, and skin reaction and pain associated with the injection. The fluid depot in the SC tissue layer was evaluated by ultrasound. Subject acceptance was evaluated using questionnaires on attitudes and emotions towards the injection technique, and challenged by seeking the subjects' preferred system for a final study injection or future treatment. RESULTS: A total of 960 injections (480 with autoinjector, 480 with syringe) were performed in 40 subjects. There were no significant differences in mean fluid leakage and injected volumes between the systems. Pain associated with the injection was significantly lower with the auto-injector than with the syringe. Local skin reaction at the injection site was overall satisfactory. Injections were appropriately performed by all subjects. At study end, all 40 subjects preferred the autoinjector for a final study injection and for future treatment. CONCLUSION: This study indicated that the autoinjector used by the subject was similar to a syringe used by a nurse in terms of performance and safety in administering the injections, and better in terms of pain, overall acceptance, and preference.
