Results of a human factors experiment of the usability and patient acceptance of a new autoinjector in patients with rheumatoid arthritis

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.