A systematic review of illness perception interventions in type 2 diabetes: Effects on glycaemic control and illness perceptions

Aims This systematic review sought to synthesize the evidence regarding the effectiveness of illness perception interventions compared with control conditions at changing illness perceptions and improving glycaemic control in individuals with type 2 diabetes. Methods Seven electronic databases were searched between October 2018 and May 2020. Randomized controlled trials that tested interventions informed by the Common-Sense Model in adults with type 2 diabetes, and measured illness perceptions and glycaemic control at pre- and post-intervention were included. The Cochrane risk of bias tool was used to assess risk of bias. Results A total of 4095 articles were identified, of which nine randomized control trials (2561 participants) across 12 publications were included in this review. Findings showed that all the illness perception domains were modified in at least one trial, with the exception of cyclical timeline perceptions. Coherence, personal control, treatment control and chronic timeline perceptions were the most frequently modified perceptions. Glycaemic control demonstrated an improvement in the intervention group compared to the control group at 3 and 6 months post-intervention in two trials. Risk of bias assessment showed high risk of bias especially for the blinding of participants and the personnel domain. Conclusions There is limited evidence that interventions informed by the Common-Sense Model can improve glycaemic control in individuals with type 2 diabetes through changing inaccurate illness perceptions. Recommendations for future research are to tailor intervention content based on baseline perceptions, measure the emotional and causal domains, and involve family members in the intervention. (PROSPERO registration: CRD42019114532).