Adherence patterns in patients with type 2 diabetes on basal insulin analogues: missed, mistimed and reduced doses

Objective: To describe basal insulin analogue dosing irregularities, the effect of these events on patient functioning, well-being and diabetes management, and the identification of patients most at risk. Research design and methods: The GAPP2 (Global Attitude of Patients and Physicians 2) study was an online multinational cross-sectional study of patients with type 2 diabetes currently treated with basal insulin, and healthcare professionals (HCPs) involved in the care of such patients. Basal insulin adherence patterns were evaluated with respect to three types of dosing irregularity: missed, mistimed [+/- 2 hours from prescribed time], and reduced dose over the last 30 days. Results: A total of 3042 patients treated with basal insulin analogues and 1222 prescribers completed the full survey; 38% of patients reported any type of basal insulin dosing irregularity in the last 30 days. Patients reported missing (22% on 3 +/- 0.16 occasions), mistiming (24% on 4.2 +/- 0.21 occasions) or reducing (14% on 4.2 +/- 0.24 occasions) basal insulin doses, with 15% of patients reporting multiple types of dosing irregularities. For most patients, missed (83%) and mistimed doses (82%) were unintentional, whereas the majority (87%) of patients reducing doses did so intentionally. Patients who intentionally missed or reduced a dose of basal insulin were significantly more likely to have performed this dosing irregularity on multiple occasions. Fifty-three percent of patients increased the frequency of blood glucose monitoring, and 17% of patients extended the duration of more frequent blood glucose monitoring by one or more days as a result of unintentional missed doses. Reduced dosing was highest in a subset of patients reporting self-treated hypoglycaemia. Conclusions: Basal insulin dosing irregularities including missed, mistimed and reduced doses are common. A significant proportion of patients also report undertaking these irregular dosing behaviours at a frequency that would be considered by prescribers to negatively impact diabetes management. This is despite the potential under-reporting due to recall or social bias that may be a limitation of a self-reported survey around these behaviours.