Comparison of usability and patient preference for insulin pen needles produced with different production techniques: "thin-wall" needles compared to "regular-wall" needles: an open-label study.

Background: People with diabetes mellitus on insulin therapy increasingly prefer insulin pens over syringes and vials. Different types of pen needles are available for insulin pens, e.g., "thin-wall" needles, which have the same outer diameter but a relatively lager inner diameter compared to needles produced with a "regular-wall."

Methods: We conducted a multicenter open-label, single-arm study in patients (n = 97) with diabetes mellitus using insulin pens. The aim of our study was to evaluate pen user habits as well as to assess patient's appraisals and ratings considering two different types of 31-gauge pen-needles, so-called "thin-wall" needles or "regular-wall" needles." Patients twice underwent a 2-week intervention period, starting with a "regular-wall period" followed by a "thin-wall-period." After each period patients filled in questionnaires.

Results: In total, 97 diabetes patients (48% female; mean age, 56 years; range, 20-70 years) completed the study. Patients reported significantly less pain, less bleeding, less skin irritation, less injection strain, less residual insulin leakage from the needle tip after injection, and less needle occlusion when using "thin-wall needles" (P < 0.001). A higher proportion of patients expressed an overall preference for the "thin-wall" needles (78%) compared to the "regular-wall" needles (8%) (P < 0.001).

Conclusions: Pen and pen needle handling, preparation, and execution of injections should be a part of repeated diabetes education and be re-evaluated on a regular basis. The "thin-wall" 31-gauge needle was found to be more user-friendly and consequently preferred by the patients. Additional larger-scale trials using blinded and randomized study designs are needed to validate these findings.