Nutrition Knowledge and Food Literacy Among Persons with Multiple Sclerosis-Development and Validation of...

Persons with MS (pwMSs) are often confronted with contradictory dietary advice, which is not always based on sound scientific evidence. This may lead to poor MS-specific nutrition knowledge (MSNK) and food literacy (MSFL). To date, no studies have assessed MSNK and MSFL among pwMSs. Moreover, no validated tools to measure the effects of educational interventions are available. The aim of this study was to develop and validate MS-specific instruments to measure MSNK and MSFL among pwMSs.

Based on a validated food literacy (FL) screener for the general population and prior research about the information needs of pwMSs, we developed 14 MSFL items and 11 MS-specific nutrition knowledge questions. Cognitive debriefing was conducted with 10 pwMSs and resulted in a 12-item MS food literacy questionnaire (MSFLQ) and an 11-item MS nutrition knowledge questionnaire (MSNKQ). After refinement, both questionnaires were pilot tested in an online survey to explore their comprehensibility. The MSNKQ was analyzed descriptively (mean and percentage of correctly answered questions). For MSFLQ item difficulty, the discriminatory power of the items, internal consistency and convergent/divergent validity were assessed.

In total, 148 pwMSs (age: 47.1 years (SD = 12.5); 102 women (69%)) completed the online survey. On average, participants answered 3.51/11 MSNK questions correctly (31.9%). The MSFLQ showed good internal consistency (Cronbach's alpha = 0.85), item difficulty was good and the discriminatory power of the items was satisfactory. Correlations between the MSFLQ and a general food literacy questionnaire was high (r = 0.626, p < 0.001), but only small with the MSNKQ (r = 0.180; p = 0.029), underlining the different constructs.

MSNK among pwMSs in Germany is low. The MSNKQ and MSFLQ appear to be suitable instruments to assess MSNK and MSFL and might serve as outcome measures for educational interventions.