Aims/hypothesis: The aim of this study was to measure the efficacy of motivational interviewing (MI) compared with usual care on changes in glycaemic control and competence of diabetes self-management in patients with diabetes mellitus.
Methods: Patients were eligible if they had type 1 or 2 diabetes mellitus, were over 18 years of age and had participated in a 4 day group education programme offered at a diabetes clinic at a university hospital in Denmark. Exclusion criteria included pregnancy, severe debilitating disease and cognitive deficit. Out of 469 patients who attended the group education programme, 349 patients were randomised to either a usual care control group or an intervention group, which received up to five individual counselling sessions in 1 year based on MI, in addition to usual care. A randomised parallel design was used and open-label allocation was done by random permuted blocks, with allocation concealment by sequentially numbered, sealed, opaque envelopes. The primary outcome was glycated haemoglobin (HbA(1c)). Analysis regarding measurements of glycated haemoglobin (HbA(1c)) and competence of self-management (using the Problem Areas in Diabetes Scale [PAID] and Perceived Competence for Diabetes Scale [PCDS]) was based on 298 participants followed for a 24 month period. Data were collected at the Department of Endocrinology at Odense University Hospital. Our hypotheses were that MI could: (1) reduce HbA(1c) levels; (2) increase self-efficacy; and (3) increase diabetes self-care, compared with usual care.
Results: Out of the 176 included in the control group and 173 in the intervention group, 153 and 145 were analysed in the groups, respectively. When using the baseline value as covariate there were no significant differences in change score between the two study groups with regard to mean level of HbA(1c) (0.131, p = 0.221), PAID scores (-1.793, p = 0.191) or PCDS scores (0.017, p = 0.903) at the 24 month follow-up, using a mixed effects regression model. The patients in the intervention group showed significantly higher levels of perceived competence in dealing with diabetes compared with the control group (mean change score = -0.387, p = 0.002) following 1 year of intervention.
Conclusion/interpretation: We were unable to demonstrate any benefit, over or above usual care, of MI in patients with diabetes who have just completed a diabetes education programme, and who have well-regulated diabetes.
Trial registration: Clinical Trials NCT00555854.