Comparison between adherence assessments and blood glucose monitoring measures to predict A1c in type 1 diabetes
© Teló et al. 2015
Published: 11 November 2015
Treatment adherence is crucial in patients with diabetes; however, there is disagreement on how to measure adherence in adults with type 1 diabetes (T1D). Surveys have been validated to evaluate adherence, and several studies have demonstrated a strong correlation between frequency of blood glucose monitoring (BGM) and glycemic control.
We conducted multivariable regression analyses to compare adherence assessments and BGM measures with regard to their ability to predict A1c in adults with T1D.
Materials and methods
Four instruments evaluated adherence: Self-Care Inventory-Revised version (SCI-R), a self-administered survey; Diabetes Self Monitoring Profile (DSMP), a survey administered by trained researchers; a categorical (yes/no/sometimes) self-report question (“In the past month, did you take care of your diabetes as your doctor recommended?”); and a continuous adherence self-evaluation, which ranged from 0-100. BGM frequency was evaluated by self-report, BGM diary, and meter download. Glycemic control was assessed by A1c (HPLC).
Participants (N=82; 63% males) were aged 39.0±13.1 yrs. with a mean diabetes duration of 21.2±11.1 yrs.; 27% had BGM frequency >4 times/day and 39% were overweight/obese. Mean A1c was 8.9±2.2% and only 11% met the target HbA1c of <7%.The adherence assessments appeared to be interrelated (P<0.01), as well as the BGM measures (P<0.001). Among the adherence assessments, DSMP score was the strongest predictor of glycemic control (r=-0.32, P=0.004), while BGM assessed by meter download was the strongest predictor of A1c among the BGM measures (r=-40, P<0.001). Moreover, the correlation between DSMP score and BGM by meter download was the strongest identified correlation in the adherence and BGM measures (r=0.52, P<0.001). All the self-report assessments had a significant but weak correlation with glycemic control (r=-0.27,-0.28; P≤0.02). The final adjusted model identified the assessment of BGM frequency by meter download as the most robust predictor of A1c (estimate effect size=-0,58, P=0.003). Demographics and clinical characteristics did not have an impact on the adherence-glycemic control relationship (P>0.05).
This study provided an opportunity to evaluate and compare adherence assessments to predict HbA1c. Although surveys like DSMP are an easy-to-use instrument to assess adherence, BGM assessment by meter download seems to have the strongest relationship with glycemic control in adults with T1D.
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