Short, Subjective Measures of Numeracy and General Health Literacy in an Adult Emergency Department

Abstract

Objectives To evaluate the reliability and validity of brief subjective measures of numeracy and general health literacy in the adult emergency department setting. Methods A convenience sample of adult emergency department patients completed subjective measures of general health literacy (Short Literacy Screening questions, SLS) and numeracy (Subjective Numeracy Scale, SNS). These patients also completed two objective tests of literacy (the Short Test of Functional Health Literacy in Adults, S-TOFHLA; and the Rapid Estimate of Adult Literacy in Medicine, REALM) and an objective test of numeracy (WRAT4). Internal reliability of the subjective measures was assessed using Cronbach’s alpha. Construct validity of the subjective measures was assessed by correlating them against the S-TOFHLA, REALM, and WRAT4, using Spearman’s rank correlation coefficients, receiver operating characteristics (ROC) curves, and hierarchical, multiple linear regression with adjustment for patient age, gender, race, and education. Results The median age of the 207 patients surveyed was 46 (interquartile range 32, 59); twenty-seven percent were African American. Sixty-one percent of patients reported their highest level of education was high school or below. As measured by the S-TOFHLA and REALM, most patients had adequate literacy levels (89% and 80%, respectively), while 44% of patients had below average numeracy skills on the WRAT4. Median SLS was 14 (IQR 12, 15) on a scale of 3 to 15; median SNS was 36 (IQR 30, 42) on a scale of 6 to 48. The SLS and SNS had good internal reliability, with Cronbach’s alphas of 0.74 and 0.82, respectively. The SLS Spearman’s rank order correlation coefficient was 0.33 (95% confidence interval 0.20, 0.45) for the S-TOFHLA, with a standardized beta coefficient of 0.36 (p<0.05) after adjustment for patient demographics. The SLS correlation coefficient was 0.26 (95% CI 0.13, 0.38) for the REALM, with a standardized beta coefficient of 0.38 (p<0.05) after adjustment for patient demographics. The area under the curve (AUC) for the SLS ROC curves was 0.74 (95% CI 0.68, 0.80) when compared to the S-TOFHLA and 0.72 (95% CI 0.65, 0.78) when compared to the REALM. The SNS predicted numeracy well, with a correlation coefficient of 0.57 (95% CI 0.47,0.65) for the WRAT4, a standardized beta coefficient of 0.30(p<0.05) after adjustment for patient demographics, and an ROC AUC of 0.77 (95% CI of 0.70, 0.82). Conclusions The SNS and SLS are reliable, valid tests that can be used to rapidly estimate general health literacy and numeracy skill levels in adult emergency department patients. Continuing work is needed to establish their ability to predict clinical outcomes.

Using Health Literacy and Learning Style Preferences to Optimize the Delivery of Health Information

“…The reported percentage of adequate health literacy was consistent with that observed in settings with comparable patient populations (Matsuyama et al, 2011;McNaughton et al, 2011). Our study was not powered to compare changes in learning across different literacy levels.…”

“…We compared health literacy scores determined by the S-TOFHLA and the Chew and colleagues (2004) questions and found a correlation between the two assessments, as described previously (Chew et al, 2008;McNaughton et al, 2011). We found the Chew and colleagues (2004) questions were easier and faster to administer than the S-TOFHLA and were therefore better suited for the workflow of a fast-paced clinical setting.…”

“…The Chew and colleagues (2004) health literacy questions were previously shown to identify low health literacy patients equally well as the S-TOFHLA (Chew et al, 2008;McNaughton, Wallston, Rothman, Marcovitz, & Storrow, 2011). A similar significant correlation between the two assessments (Spearman's correlation (98) 44 (98) 49 (100) 54 (100…”

Emergency Physician Perceptions of Shared Decision‐making

“…Some have proposed that in preference-sensitive decisions, patients need exact probabilities of harms and benefits associated with each option to appropriately weigh the pros and cons of each; 6 however, these probabilities are often not available in EM, and even when they are, both patients and physicians may be limited by the inherent challenges of effective risk communication. [10][11][12][13][14] Finally, patients who are potentially critically ill may prefer that clinicians take a more dominant role in decision-making. [15][16][17][18] Despite nationwide efforts and focus on patient-centeredness, viewpoints of frontline practicing clinicians on how practically to achieve increased patient engagement remain largely unknown.…”

Impact of numeracy on parental self-efficacy and treatment outcome of children on complex diets.

“…Therefore, research on health numeracy is found both within health literacy studies, and in numeracy-specific articles. Subjective measures of numeracy and health literacy have indicated that they are related but unique skills (C. D. McNaughton, Rothman, R., Marcovitz, D.E., Storrow, A.B., 2011). In studies that have assessed both health literacy and numeracy in relation to the same health outcomes, numeracy has been more highly correlated with outcomes than health literacy (Marden et al, 2012; R. L. Rothman et al, 2006).…”