Effects of Diabetes Numeracy on Glycemic Control and Diabetes Self-Management Behaviors in Patients on Insulin Pump Therapy

Diabetes numeracy (DN) skills are crucial in patients on insulin pump therapy. Little evidence exists regarding DN in this patient population.

This exploratory, observational, cross-sectional study assessed the DN levels of patients on insulin pump therapy and potential relationships with glycemic control and self-management behaviors. Seventy-two patients on insulin pump therapy were recruited from one specialty endocrinology clinic. Subjects completed validated tools to measure DN [Diabetes Numeracy Test (DNT-15)] and self-management behaviors [Diabetes Self-Management Questionnaire (DSMQ)]. A general diabetes questionnaire assessed socioeconomic information and self-efficacy. Additional self-management behaviors and glycemic control data were collected from patients’ medical records. Patients were categorized into two groups based on DNT-15 scores to explore potential relationships between DN scores and patient characteristics, glycemic control, and self-management behaviors.

Average age was 52 ± 15 years, glycosylated hemoglobin (A1C) was 7.7% ± 1.2% (61 mmol/mol), duration of diabetes was 28 ± 15 years, and duration of pump use was 3.4 ± 1.3 years. The average DNT-15 score was 87.5% ± 18%. Forty-three participants (60%) scored ≥ 90% and 29 participants (40%) scored < 90%. Eighteen percent were unable to calculate the carbohydrate content from a nutrition label. Participants with lower DNT-15 scores had higher A1C levels (8.0% vs. 7.5%, p = 0.04), were older (58.3 vs. 47.7, p = 0.003), were more likely to describe their diabetes self-care as poor (p = 0.04), and were less confident in using their pump features (p = 0.02) than those with higher DNT-15 scores.

Many patients on insulin pump therapy have deficiencies with DN which may be associated with older age and higher A1C levels.