Health literacy assessment using talking touchscreen technology (Health LiTT): A new item response theory-based measure of health literacy

The importance of health literacy has grown considerably among researchers, clinicians, patients, and policymakers. Better instruments and measurement strategies are needed. Our objective was to develop a new health literacy instrument using novel health information technology and modern psychometrics. We designed Health LiTT as a self-administered multimedia touchscreen test based on item response theory (IRT) principles. We enrolled a diverse group of 619 English-speaking, primary care patients in clinics for underserved patients. We tested three item types (prose, document, quantitative) that worked well together to reliably measure a single dimension of health literacy. The Health LiTT score meets psychometric standards (reliability of 0.90 or higher) for measurement of individual respondents in the low to middle range. Mean Health LiTT scores were associated with age, race/ethnicity, education, income, and prior computer use (p.05). We created an IRT-calibrated item bank of 82 items. Standard setting needs to be performed to classify and map items onto the construct and to identify measurement gaps. We are incorporating Health LiTT into an existing online research management tool. This will enable administration of Health LiTT on the same touchscreen used for other patient-reported outcomes, as well as real-time scoring and reporting of health literacy scores.