Quick Assessment of Literacy in Primary Care: The Newest Vital Sign

TLDR

Health literacy screening tools in clinical settings are either too lengthy for routine use or limited to English. The study aimed to create a brief, accurate literacy screening test available in both English and Spanish. Researchers administered candidate items and the TOFHLA to English‑ and Spanish‑speaking primary care patients, evaluated internal consistency (Cronbach’s α), assessed criterion validity via correlations, and used ROC curves to determine cutoff scores. The resulting Newest Vital Sign, a 6‑question nutrition‑label test completed in 3 minutes, demonstrated good reliability (α > 0.76 English, 0.69 Spanish), strong correlation with TOFHLA, AUCs of 0.88 (English) and 0.72 (Spanish), and correctly identified limited literacy when fewer than 4 answers were correct.

Abstract

<b>PURPOSE</b> Current health literacy screening instruments for health care settings are either too long for routine use or available only in English. Our objective was to develop a quick and accurate screening test for limited literacy available in English and Spanish. <b>METHODS</b> We administered candidate items for the new instrument and also the Test of Functional Health Literacy in Adults (TOFHLA) to English-speaking and Spanish-speaking primary care patients. We measured internal consistency with Cronbach’s α and assessed criterion validity by measuring correlations with TOFHLA scores. Using TOFLHA scores &lt;75 to define limited literacy, we plotted receiver-operating characteristics (ROC) curves and calculated likelihood ratios for cutoff scores on the new instrument. <b>RESULTS</b> The final instrument, the Newest Vital Sign (NVS), is a nutrition label that is accompanied by 6 questions and requires 3 minutes for administration. It is reliable (Cronbach α &gt;0.76 in English and 0.69 in Spanish) and correlates with the TOFHLA. Area under the ROC curve is 0.88 for English and 0.72 for Spanish versions. Patients with more than 4 correct responses are unlikely to have low literacy, whereas fewer than 4 correct answers indicate the possibility of limited literacy. <b>CONCLUSION</b> NVS is suitable for use as a quick screening test for limited literacy in primary health care settings.