Measurement variation across health literacy assessments: implications for assessment selection in research and practice.

National priorities and recent federal initiatives have brought health literacy to the forefront in providing safe accessible care. Having valid and reliable health literacy measures is a critical factor in meeting patients' health literacy needs. In this study, the authors examined variation across three brief health literacy instruments in categorizing health literacy levels and identifying associated factors. The authors screened 378 veterans using the short form of the Test of Functional Health Literacy in Adults; the Rapid Estimate of Adult Literacy in Medicine; and a 4-Item Brief Health Literacy Screening Tool (known as the BRIEF). They analyzed data using prevalence estimates, Pearson product moment correlations, and logistic regression. When categorizing individuals' health literacy, agreement among instruments was present for 37% of the sample. There were consistencies; however, categorization and estimated risk factors varied by instrument. Depending on instrument, increased age, low education, minority status, and self-reported poor reading level were associated with low health literacy. Findings suggest that these instruments measure health literacy differently and are likely conceptually different. As the use of health literacy screening gains momentum, alignment between instrument and intended purpose is essential; in some cases, multiple instruments may be appropriate. When selecting an instrument, one should consider style of administration, purpose for measure, and availability of time and resources.