Effectiveness of a PLISSIT model intervention in patients with type 2 diabetes mellitus in primary care: design of a cluster-randomised controlled trial

Background: Sexual dysfunction is prevalent in patients with type 2 diabetes mellitus, but remains one of the most frequently neglected complications in diabetes care. Both patients and care providers appear to have difficulty with discussing sexual problems in diabetes care. A sexual counselling model for care providers, such as the PLISSIT model, might be a useful tool to improve the discussion of sexual issues in patients with type 2 diabetes mellitus. PLISSIT stands for Permission, Limited Information, Specific Suggestions, and Intensive Therapy. Even though the use of the PLISSIT model has often been recommended in diabetes care, no evidence with regards to its effectiveness in patients with type 2 diabetes mellitus exists. This study describes the design of a cluster-randomised controlled trial evaluating the effectiveness of a PLISSIT-model intervention in men and women with type 2 diabetes mellitus in primary care. Methods/Design: Patients with type 2 diabetes mellitus, aged 40-75 years, who indicate to be dissatisfied about their sexual functioning and that they would like to talk about their sexual problem(s) with their general practitioner are recruited. All participants receive an information leaflet from the practice nurse. In the intervention group, each participant will also receive sexual counselling based on the PLISSIT model from their general practitioner. In the control group, usual care will be provided to those participants requesting an appointment with their general practitioner when the information leaflet was not deemed sufficient. Primary outcomes include sexual functioning, satisfaction about sexual function, and quality of life. Secondary outcomes are depressive symptoms, sexual distress, emotional well-being, and treatment satisfaction. Outcomes will be measured by means of self-report questionnaires at baseline, and after 3 and 12 months post-baseline. Treatment satisfaction will be assessed in telephone interviews. Discussion: This paper describes the design of a cluster-randomised controlled trial that will investigate the effectiveness of a PLISSIT-model intervention in patients with type 2 diabetes mellitus in primary care. Our study will add important and currently missing insight into the effectiveness of PLISSIT on important patient-reported outcomes of men and women with type 2 diabetes mellitus.