937Rasch analysis of the Health Literacy Questionnaire in the Understanding Multiple Sclerosis online course cohort

Abstract

Abstract Background We have built a six-week free online course to improve multiple sclerosis (MS)-related knowledge, health literacy (HL), and resilience among members of the MS community and interested laypeople, entitled Understanding MS. To evaluate the effectiveness of the course, we require an appropriate tool to measure HL in this cohort. Objective To evaluate the psychometric properties of the multidimensional Health Literacy Questionnaire (HLQ) in a cohort of Understanding MS online course enrolees. Methods Participants who enrolled in the first two open enrolments of the Understanding MS online course completed the HLQ (n = 1182) in an online survey prior to beginning course materials. We used Rasch analysis to assess the measurement properties of the HLQ. Results The nine subscales of the HLQ each had a good fit with the Rasch model; they were unidimensional, had good internal consistency and reliability and no item bias or local dependency measurement gaps were identified for participants with low or high scores in each of the nine subscales, creating a ceiling effect, meaning that the HLQ cannot reliably measure change in HL over time for these participants. The HLQ is a reliable measurement tool to assess change in HL for people with low to moderate HL levels who have room to improve, which is our target group. Conclusion The HLQ is useful for assessing HL in this and similar cohorts, but the assessment of HL change should consider the limitations described above. Key messages The HLQ has excellent measurement properties and is appropriate for assessing HL