Validation of Screening Questions for Limited Health Literacy in a Large VA Outpatient Population

• Published in: Journal of general internal medicine : JGIM 2008-05, Vol.23 (5), p.561-566
• Main Authors: Chew, Lisa D., Griffin, Joan M., Partin, Melissa R., Noorbaloochi, Siamak, Grill, Joseph P., Snyder, Annamay, Bradley, Katharine A., Nugent, Sean M., Baines, Alisha D., VanRyn, Michelle
• Format: Article
• Language: English
• Subjects: Aged; Biological and medical sciences; Chemical Sciences; Educational Status; Female; General aspects; Health Knowledge, Attitudes, Practice; Hospitals, Veterans; Humans; Internal Medicine; Interviews as Topic; Male; Medical sciences; Medical screening; Medicine; Medicine & Public Health; Middle Aged; Miscellaneous; Organic chemistry; Original; Original Article; Outpatient care facilities; Prevention and actions; Public health. Hygiene; Public health. Hygiene-occupational medicine; Questionnaires; ROC Curve; Surveys and Questionnaires; United States; Veterans
• ISSN: 0884-8734; 1525-1497
• DOI: 10.1007/s11606-008-0520-5

Objectives Previous studies have shown that a single question may identify individuals with inadequate health literacy. We evaluated and compared the performance of 3 health literacy screening questions for detecting patients with inadequate or marginal health literacy in a large VA population. Methods We conducted in-person interviews among a random sample of patients from 4 VA medical centers that included 3 health literacy screening questions and 2 validated health literacy measures. Patients were classified as having inadequate, marginal, or adequate health literacy based on the Short Test of Functional Health Literacy in Adults (S-TOFHLA) and the Rapid Estimate of Adult Literacy in Medicine (REALM). We evaluated the ability of each of 3 questions to detect: 1) inadequate and the combination of “inadequate or marginal” health literacy based on the S-TOFHLA and 2) inadequate and the combination of “inadequate or marginal” health literacy based on the REALM. Measurements and Main Results Of 4,384 patients, 1,796 (41%) completed interviews. The prevalences of inadequate health literacy were 6.8% and 4.2%, based on the S-TOHFLA and REALM, respectively. Comparable prevalences for marginal health literacy were 7.4% and 17%, respectively. For detecting inadequate health literacy, “How confident are you filling out medical forms by yourself?” had the largest area under the Receiver Operating Characteristic Curve (AUROC) of 0.74 (95% CI: 0.69–0.79) and 0.84 (95% CI: 0.79–0.89) based on the S-TOFHLA and REALM, respectively. AUROCs were lower for detecting “inadequate or marginal” health literacy than for detecting inadequate health literacy for each of the 3 questions. Conclusion A single question may be useful for detecting patients with inadequate health literacy in a VA population.