BackgroundThe national guideline for diabetes type 2 claims to involve patients in their decision-making on therapy. Unfortunately, no structured, pharmaceutical-neutral curriculum is available to guide patients in this shared decision-making (SDM) process regarding the insulin injector. The aim of the study was to evaluate which injector patients chose after SDM process and the reasons for their choice.MethodsWe developed a curriculum for a SDM process to choose an insulin injector for insulin-naive patients with diabetes mellitus, which took place immediately before the start of the initial treatment with insulin. It was conducted by a physician or diabetes educator with no conflicts of interest. All available human short-acting disposable insulin injectors (A, B and C) were handed out for try-out accompanied by individual counselling. The patients selected their injector of choice and were asked immediately afterwards about the criteria for their selection.Results349 consecutive patients (94% diabetes type 2; age 58.6 + 13.4y; HbA1c 10.4 + 2.1%) were included. Patients choose Injector A in 10.0%, B in 61.9% and C in 28.1%. Criteria for selection were: design (41.8%), general impression (23.5%), dose window (7.7%), dose selection dial (7.4%), most practical (6.6%) and other (13%). Selection of a specific injector was not associated with age, diabetes type, diabetes duration, BMI, HbA1c, presence of concomitant diseases, retinopathy, neuropathy, diabetic foot or physician/diabetes educator.DiscussionInsulin-naive patients with diabetes mellitus chose their own insulin injector within a newly developed structured SDM process to meet the national guideline. Main selection criteria were design and practicability.