Diabetes Care Protocol: effects on patient-important outcomes. A cluster randomized, non-inferiority trial in primary care

Abstract

Aims The Diabetes Care Protocol (DCP) combines task delegation, intensification of diabetes treatment and feedback. It reduces cardiovascular risk in Type 2 diabetes (T2DM) patients. This study determines the effects of DCP on patient-important outcomes. Methods A cluster randomized, non-inferiority trial, by self-administered questionnaires in 55 Dutch primary care practices: 26 practices DCP (1699 patients), 26 usual care (1692 patients). T2DM patients treated by their general practitioner were included. Main outcome was the 1-year between-group difference in Diabetes Health Profile (DHP-18) total score. Secondary outcomes: DHP-18 subscales, general perceived health [Medical Outcomes Study 36-Items Short Form Health Survey (SF-36), Euroqol 5 Dimensions (EQ-5D) and Euroqol visual analogue scale (EQ-VAS)], treatment satisfaction (Diabetes Treatment Satisfaction Questionnaire; DTSQ status) and psychosocial self-efficacy (Diabetes Empowerment Scale Short Form; DES-SF). Per protocol (PP) and intention-to-treat (ITT) analyses were performed: non-inferiority margin Δ = −2%. At baseline 2333 questionnaires were returned and 1437 1 year thereafter. Results Comparing DCP with usual care, DHP-18 total score was non-inferior: PP −0.88 (95% CI −1.94 to 0.12), ITT −0.439 (95% CI −1.01 to 0.08), SF-36 ‘health change’ improved: PP 3.51 (95% CI 1.23 to 5.82), ITT 1.91 (95% CI 0.62 to 3.23), SF-36 ‘social functioning’ was inconclusive: PP −1.57 (95% CI −4.3 to 0.72), ITT −1.031 (95% CI −2.52 to −0.25). Other DHP and SF-36 scores were inconsistent or non-inferior. DHP-18 ‘disinhibited eating’ was significantly worse in PP analyses. For EQ-5D/EQ-VAS, DTSQ and DES-SF, no significant between-group differences were found. Conclusion DCP does not seem to influence health status negatively, therefore diabetes care providers should not shrink from intensified treatment. However, they should take possible detrimental effects on ‘social functioning’ and ‘disinhibited eating’ into account.