Studies of educational interventions and outcomes in diabetic adults: a meta-analysis revisited

This paper reports a follow-up of previous meta-analysis research conducted by the author on the effects of diabetes patient education on patient outcomes. An expanded sample of studies and psychological outcome variables were added to the previously studied variables of patient knowledge, self-care behaviors (compliance and skill performance) and metabolic control. The purpose was to determine: (1) the effects of patient education on specific outcome variables; and (2) the relationships between effects of education and characteristics of the studies and/or subjects. Following an extensive literature search, a total of 82 studies were found which met the inclusion criteria for this analysis; 68% were published and 32% were unpublished. Homogeneity analyses of specific patient outcome variables yielded the following results: knowledge effects ranged from 0.49 to 1.05; self-care behavior effects from 0.17 to 0.57, with insulin injection and weight loss associated with the smallest effect sizes; metabolic control from 0.16 to 0.41; and psychological outcomes 0.27. Mean age of the subjects was negatively correlated with knowledge and cholesterol, indicating that the older the mean age of the subjects, the lower the effects of patient education on these variables. Findings of this meta-analysis on the expanded data set were consistent with the previous meta-analysis and lend support to the effectiveness of diabetes patient education in improving patient outcomes.