Examination of an eHealth literacy scale and a health literacy scale in a population with moderate to high cardiovascular risk: Rasch analyses

Richtering, Sarah S.; Morris, Rebecca; Soh, Sze-Ee; Barker, Anna; Bampi, Fiona; Neubeck, Lis; Coorey, Genevieve; Mulley, John; Chalmers, John; Usherwood, Tim; Peiris, David; Chow, Clara K.; Redfern, Julie

Abstract

Introduction
Electronic health (eHealth) strategies are evolving making it important to have valid scales to assess eHealth and health literacy. Item response theory methods, such as the Rasch measurement model, are increasingly used for the psychometric evaluation of scales. This paper aims to examine the internal construct validity of an eHealth and health literacy scale using Rasch analysis in a population with moderate to high cardiovascular disease risk.
Methods
The first 397 participants of the CONNECT study completed the electronic health Literacy Scale (eHEALS) and the Health Literacy Questionnaire (HLQ). Overall Rasch model fit as well as five key psychometric properties were analysed: unidimensionality, response thresh-
olds, targeting, differential item functioning and internal consistency.
Results
The eHEALS had good overall model fit (χ2 = 54.8, p = 0.06), ordered response thresholds, reasonable targeting and good internal consistency (person separation index (PSI) 0.90). It did, however, appear to measure two constructs of eHealth literacy. The HLQ subscales (except subscale 5) did not fit the Rasch model (χ2: 18.18–60.60, p: 0.00–0.58) and had sub-optimal targeting for most subscales. Subscales 6 to 9 displayed disordered thresholds indi-cating participants had difficulty distinguishing between response options. All subscales did, nonetheless, demonstrate moderate to good internal consistency (PSI: 0.62–0.82).

Citation

Richtering, S. S., Morris, R., Soh, S.-E., Barker, A., Bampi, F., Neubeck, L., Coorey, G., Mulley, J., Chalmers, J., Usherwood, T., Peiris, D., Chow, C. K., & Redfern, J. (2017). Examination of an eHealth literacy scale and a health literacy scale in a population with moderate to high cardiovascular risk: Rasch analyses. PLOS ONE, 12(4), Article e0175372. https://doi.org/10.1371/journal.pone.0175372

• Journal Article Type: Article
• Acceptance Date: Mar 6, 2017
• Online Publication Date: Apr 27, 2017
• Publication Date: Apr 27, 2017
• Deposit Date: Apr 28, 2017
• Publicly Available Date: Apr 28, 2017
• Journal: PLOS ONE
• Print ISSN: 1932-6203
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 4
• Article Number: e0175372
• DOI: https://doi.org/10.1371/journal.pone.0175372
• Keywords: Electronic health, eHealth, health literacy, cardiovascular disease,
• Public URL: http://researchrepository.napier.ac.uk/Output/834599
• Contract Date: Apr 28, 2017