Adaptation and Validation of the Iraqi Diabetic Health Literacy Questionnaire (IDHLQ): A Rasch and Factor Analysis Study

Introduction: Diabetes prevalence in Iraq is high, yet culturally adapted and psychometrically validated health literacy (HL) tools for people with diabetes remain limited. The Jordanian Diabetic Health Literacy Questionnaire (JDHLQ) assesses informational and communicative HL but omits numeracy. Purpose: To adapt and validate the Iraqi Diabetic Health Literacy Questionnaire (IDHLQ), based on the JDHLQ, which incorporates a numeracy domain, for use among adults with type 2 diabetes in Iraq. Patients and Methods: A cross-sectional study recruited 473 adults with type 2 diabetes from endocrinology clinics across Iraq. Participants were 52.7% female with a median age of 50 years (IQR: 31-60). The 11-item IDHLQ was validated using exploratory factor analysis, Rasch modeling, and Cronbach's alpha. Linear regression examined sociodemographic predictors. Results: A three-factor model emerged, representing informational, numeracy, and communicative health literacy, with internal consistency ranging from α = 0.70 to 0.86. Rasch analysis showed item separation reliability of 0.87-0.95 and person reliability of 0.65-0.82. The median score was 33 (IQR: 28-36) out of 44. Monthly income predicted HL (β = 0.16, p = 0.003), while age, gender, education, and marital status were nonsignificant. Conclusion: The adapted IDHLQ is a reliable and valid instrument for assessing multidimensional diabetic health literacy among Iraqi adults. Its use in clinical and public health settings could inform patient education strategies and guide policy development to reduce disparities in diabetes outcomes.