Validation using item response theory, and assessment of sensitivity to change of the Hypoglycemia Awareness Questionnaire in patients with type 2 diabetes treated with insulin

Aims/Introduction: It is important to develop valid tools to evaluate hypoglycemia perception such as the Hypoglycemia Awareness Questionnaire (HypoA-Q) in patients with Type 2 Diabetes (T2D). The aim of the study is to validate the HypoA-Q in patients with T2D treated with insulin using item response theory. Materials and Methods: Individuals with T2D treated with insulin were included by non-random convenience sampling. A partial credit model was used for validation using item response theory, infit, and outfit statistics were calculated, person-item map and item characteristic curves were plotted, and differential item functioning was assessed. Results: The study included 502 participants, the mean age at diagnosis of diabetes was 47.8 ± 13.9 years, the median time with the diagnosis was 15 years (IQR: 9–22), and the mean HbA1c 71 ± 27.3 mmol/mL (8.6 ± 2.5%), 48.6% had Glomerular Filtration Rate >60 mL/min/min². Item fit was found with items covering the full range of the construct of the participant population, although response options could be simplified. The person-item map showed that the scale covers a wide range of the construct and that the scale has items to measure these different levels. Item bias was not evident when comparing subgroups by age, sex and treatment. Conclusions: The HypoA-Q is a valid measure for assessing hypoglycemia awareness in insulin-treated T2D patients because it has items that fit the measurement process, measures a wide range of awareness, and is free of biases related to gender, age, treatment, and duration of diabetes.