Development of a New Measure of Housing Security: The REDD-CAT Housing Security Measure

Background Housing security is a key social determinant of behavior related to health outcomes. Objective The purpose of this study was to develop a new patient-reported outcome measure that evaluates aspects of housing security for use in the Re-Engineered Discharge for Diabetes-Computer Adaptive Test (REDD-CAT) measurement system. Design Qualitative data, literature reviews, and cross-sectional survey study. Participants A total of 225 people with T2DM provided responses to the items in this item pool. Main Measures A new item pool that evaluates important aspects of housing security was developed using stakeholder data from focus groups of persons with T2DM. Key Results For the Housing Affordability scale, factor analysis (both exploratory and confirmatory) supported the retention of six items. Of these items, none exhibited sparse cells or problems with monotonicity; no items were deleted due to low item-adjusted total score correlations. For the six affordability items, a constrained graded response model indicated no items exhibited misfit; thus, all were retained. No items indicated differential item functioning (examined for age, sex, education, race, and socioeconomic status). Thus, the final Affordability item bank comprised six items. A Housing Safety index (three items) and a Home Features index (eight items) were also developed. Reliability (i.e., internal consistency and test–retest reliability) and validity (i.e., convergent, discriminant, and known-groups) of the new measures were also supported. Conclusions The REDD-CAT Housing Security Measure provides a reliable and valid assessment of housing affordability, safety, and home features in people with type 2 diabetes mellitus. Future work is needed to establish the clinical utility of this measure in other clinical populations.