Randomized, controlled trial of diabetic patient education: improved knowledge without improved metabolic status

We randomized 749 insulin-treated patients on the rolls of the Mount Sinai Medical Center Diabetes Clinic in a controlled trial of diabetic patient education; 345 agreed to participate, of whom 165 were assigned to the education group and 180 to the control group. Cognitive scores increased from 5.3 +/- 1.6 to 5.8 +/- 1.6 in the education group, but there was no change in the control group, whose score was 5.3 +/- 1.7 before and after the intervention (P = .0073). HbA1c fell from 6.8 +/- 2.1 to 6.1 +/- 2.0% in the education group and from 6.6 +/- 2.0 to 6.3 +/- 2.0% in the control group, an insignificant difference (P = .1995). The fasting blood glucose decreased from 223 +/- 94 to 179 +/- 73 mg/dl in the education group and from 199 +/- 81 to 185 +/- 76 mg/dl in the controls (P = .1983). Triglycerides, high- and low-density lipoprotein cholesterol, and insulin dosage also failed to show significant variation among groups. The foot-lesion score showed similar progression in the education and control groups. Neither diastolic nor systolic blood pressure showed significantly greater change in the education or the control group, with falls noted, particularly in diastolic pressures, in both patient groups. Differences between the groups were not significant for sick days, hospitalizations, emergency room visits, or outpatient visits. The sample sizes of the study and control populations were sufficiently large to detect a difference in means between the education and control groups in the HbA1c, the primary outcome variable, of greater than 1.0%, with alpha = .05 and a power of .95. Thus, our study suggests that patient education may not be an efficacious therapeutic intervention in most adults with insulin-treated diabetes mellitus.