Timing of Insulin Injections, Adherence, and Glycemic Control in a Multinational Sample of People with Type 2 Diabetes: A Cross-Sectional Analysis

Introduction: We investigated the association of bolus insulin dose timing with demographics, adherence, diabetes education program participation, experience with hypoglycemic events, glycemic control, and patient preference among respondents with type 2 diabetes. Methods: Adults with type 2 diabetes from 12 countries were recruited to a Web-based self-reported patient preference survey. Adherence was measured using an adapted Morisky Medication Adherence Scale questionnaire. Results: In total 1483 respondents reported using bolus insulin with 58% (n = 864) dosing bolus insulin before meals (pre-meal cohort), 354 (24%) during or after meals (post-meal cohort), and 265 (18%) before, during, or after meals (mixed cohort). The mixed cohort was excluded, thus 1218 respondents were included in the analysis. Respondent distribution across HbA(1c) category differed significantly depending on insulin dose timing (p = 0.0006); more respondents in the post-meal cohort (40%) had HbA(1c) >= 9% (74.9 mmol/mol) than in the pre-meal cohort (29%). The post-meal cohort was significantly more likely to report non-adherence than the pre-meal cohort (OR = 1.50, p = 0.01) and significantly more often reported participating in diabetes education programs (p < 0.05). Seventy-eight percent of all respondents reported preferring bolus insulin administrable whenever convenient. Conclusions: Approximately 24% of respondents never comply with guidelines for insulin dose timing, with higher risk of non-adherence and increased participation in diabetes care programs. Respondents dosing insulin post-meal are more likely to have poor glycemic control (HbA(1c) >= 9%, 74.9 mmol/mol). Given that many respondents had high HbA(1c) and were non-adherent, a treatment which satisfies patient preference for bolus insulin with flexible dose timing could be considered.