Shared decision making and patient-centeredness for patients with poorly controlled type 2 diabetes mellitus in primary care-results of the cluster-randomised controlled DEBATE trial.

We investigate whether an educational intervention of GPs increases patient-centeredness and perceived shared decision making in the treatment of patients with poorly controlled type 2 diabetes mellitus?
We performed a cluster-randomized controlled trial in German primary care. Patients with type 2 diabetes mellitus defined as HbA1c levels ≥ 8.0% (64 mmol/mol) at the time of recruitment (n = 833) from general practitioners (n = 108) were included. Outcome measures included subjective shared decision making (SDM-Q-9; scale from 0 to 45 (high)) and patient-centeredness (PACIC-D; scale from 1 to 5 (high)) as secondary outcomes. Data collection was performed before intervention (baseline, T0), at 6 months (T1), at 12 months (T2), at 18 months (T3), and at 24 months (T4) after baseline.
Subjective shared decision making decreased in both groups during the course of the study (intervention group: -3.17 between T0 and T4 (95% CI: -4.66, -1.69; p < 0.0001) control group: -2.80 (95% CI: -4.30, -1.30; p = 0.0003)). There were no significant differences between the two groups (-0.37; 95% CI: -2.20, 1.45; p = 0.6847). The intervention's impact on patient-centeredness was minor. Values increased in both groups, but the increase was not statistically significant, nor was the difference between the groups.
The intervention did not increase patient perceived subjective shared decision making and patient-centeredness in the intervention group as compared to the control group. Effects in both groups might be partially attributed to the Hawthorne-effect. Future trials should focus on patient-based intervention elements to investigate effects on shared decision making and patient-centeredness.
The trial was registered on March 10, 2011 at ISRCTN registry under the reference ISRCTN70713571 .