Development and validation of a measure of health literacy in the UK: the newest vital sign

Abstract

BackgroundHealth literacy (HL) is an important public health issue. Current measures have drawbacks in length and/or acceptability. 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.MethodsWe 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. Inclusion criteria were age 18–75 years and ability to converse in English. We excluded people working in the health field and those with impaired vision or inability to undertake the interview due to cognitive impairment or inability to converse in English.ResultsIn the Delphi study, 28 experts reached consensus (3 cycles). Cognitive testing (80 participants) yielded an instrument that needed no further refinement. Validation testing (337 participants) showed high internal consistency (Cronbach’s Alpha = 0.74). Validation against the TOFHLA demonstrated a Pearson’s r of 0.49 and an area under the ROC curve of 0.81.ConclusionsThe NVS-UK is a valid measure of HL. Its acceptability and ease of application makes it an ideal tool for use in the UK. It has potential uses in public health research including epidemiological surveys and randomized controlled trials, and in enabling practitioners to tailor care to patient need.

International application of health literacy measures: Adaptation and validation of the newest vital sign in The Netherlands

“…Brief and easy-to-use HL measures have been developed in English, including the 'newest vital sign (NVS)', a six-question tool to assess individual's ability to find and interpret information (both text and numerical information) on an ice cream nutrition label [10] (Box I). The NVS has been widely used in the US and has recently been validated for use in the UK [11].…”

Health Literacy Measurements with The Newest Vital Sign Instrument Among Adolescents from Dubai, United Arab Emirates

“…First, it is validated, reliable, culturally appropriate, and was applied in dozens of health literacy studies globally over the past decade 17 . Second, it enhances comprehensiveness of health literacy ascertainment by assessing reading, interpretation, and numeracy.…”

Measuring Health Literacy Among Somali Men Over the Age of 45 - A Pilot Study

“…Individuals with low health literacy skills are at higher risk of poorer health (Rowlands, Khazaezadeh, Oteng-Ntim, Seed, Barr & Weiss, 2013). Adequate health literacy increases self-efficacy, and use of preventative care to promote personal health and chronic disease management (Chen et al, 2013).…”