Patient satisfaction with injection devices: a randomized controlled study comparing two different etanercept delivery systems in moderate to severe psoriasis

Background There is limited information regarding the acceptability of injection devices for biological agents. Objectives The primary objective of the study was to investigate patients' perceptions on the acceptability of two devices delivering etanercept. The secondary objectives of the study were to explore whether patients' attributes are associated with preferences. Methods This was a multicentre, open-label, randomized, parallel-design study. Adult patients with psoriasis were randomized to receive etanercept 50 mg twice-weekly subcutaneously for 12 weeks, either as a pre-filled syringe or as a pre-filled pen. The primary outcome was the patient satisfaction at week 12 with the injection device, as measured on a 0-10-point Likert scale. The study was powered to demonstrate non-inferiority of a pen over a syringe for the primary endpoint. Results A total of 421 patients were randomized. Mean patient satisfaction at week 12 was 8.9 (+/- 1.9) points in the pen group and 7.6 (+/- 2.6) points in the syringe group. There was a statistically significant advantage for the pen compared with the syringe. Multiple correspondence analysis showed that very satisfied patients were the oldest and had had psoriasis for a longer duration, while less satisfied patients were the most anxious and depressed. PASI 75 response was achieved by 61% of patients in the pen group and 57% in the syringe group at week 12. Conclusions This study showed higher patient satisfaction when injecting etanercept with a pen compared with a syringe. Factors associated with lower satisfaction are younger age, anxiety and depression.