Developing and validating trust measures
The US-developed Newest Vital Sign (NVS) health literacy instrument measures both reading comprehension and numeracy skills using a nutrition label, takes 3 minutes to administer, and has proven to be acceptable to research subjects.
This study aimed to amend and validate it for the UK population.
Where there is a mismatch between individuals’ health-related literacy and numeracy skills and the demands of the health system, those with lower skills are at risk of poorer health.
Low HL is associated with limited participation in screening for diseases, limited understanding of one’s illness or treatment plan, difficulties managing a chronic conditions such as diabetes mellitus, coronary health disease, heart failure, and asthma, poorer overall health status .
All Health Literacy Group UK members were invited by email to participate and all who expressed an interest were recruited.
We asked these experts to assess nutrition labels used in the UK, to compare their content and layout to the nutrition label used on the original (US) version of the NVS, and to suggest modifications of the original NVS nutrition label to make it concordant with UK nutrition labels.
Now described in more than 50 peer-reviewed journal articles, the NVS consists of a food nutrition label with six associated questions giving scores from 0 to 6 .
The length of time required for administration of the TOFHLA (22 minutes or more for the full version and up to 10 minutes for the shortened version) precludes its use in busy clinic settings and significantly increases the length of participant questioning if used in research.We also asked them to make suggestions for modifying the wording of the questions that accompany the nutrition label.The intent of these modifications was to make the style of English in the questions correspond to common usage in the UK.We used a three-stage process; (1) a Delphi study with academic and clinical experts to amend the NVS label to reflect UK nutrition labeling (2) community-based cognitive testing to assess and improve ease of understanding and acceptability of the test (3) validation of the NVS-UK against an accepted standard test of health literacy, the Test of Functional Health Literacy in Adults (TOFHLA) (Pearson’s r and the area under the Receiver Operating Characteristic (ROC) curve) and participant educational level.A sample size calculation indicated that 250 participants would be required.
Search for developing and validating trust measures:
The ability to understand both language and numbers in health contexts are core competencies.