Health LiteracyThe association between health literacy and indicators of cognitive impairment in a diverse sample of primary care patients
Introduction
Health Literacy Assessment Using Talking Touchscreen Technology (Health LiTT) is a new computer-based tool that can be used in clinical practice and research to assess patients’ health literacy [1], [2]. For the purpose of this measurement tool, we define health literacy as the capacity to read and comprehend health-related print material, identify and interpret information presented in graphical format (charts, graphs and tables), and perform arithmetic operations in order to make appropriate health and care decisions [3]. Health LiTT was created to measure a breadth of literacy levels and can be administered as a short form test or using computer adaptive testing (CAT). CAT uses computer algorithms to select the best test items based on responses to previous items. This approach minimizes the assessment length, while maximizing the precision of the measurement of health literacy. As a new tool, it is important to know how Health LiTT is related to other commonly used measures in the health care setting: (1) cognitive ability, and (2) years of education.
Health LiTT has been shown to be acceptable to a wide variety of patients, including those who are computer naïve and older [2], and initial evidence supports the validity of this new tool [1], [4]. Validation of a new measurement tool requires building a weight of evidence demonstrating that the instrument is measuring the construct of interest and that the scores behave as hypothesized [5]. Two variables consistently shown to be independently associated with better health literacy in numerous previous studies are normal cognitive ability and higher educational attainment [6], [7], [8], [9], [10], [11], [12], [13]. The relationship between health literacy, cognitive ability, and education is complex and the causal direction of the associations is difficult to tease apart [8]. However, demonstrating independent associations of cognitive ability and education with health literacy as measured by Health LiTT would further support the validity of this new measure.
The overall objective of this study was to determine whether the established associations between health literacy, education, and cognitive ability are confirmed when health literacy is measured by the new Health LiTT. The strength of association between health literacy and cognitive ability may vary by how these constructs are measured [13]. Thus, a secondary objective was to assess whether the association between health literacy and cognitive ability differed by type of cognitive task.
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Participants
Data for this unplanned secondary analysis were from a sample of primary care patients who participated in a study to develop and calibrate Health LiTT [1], [2]. Participants in the parent study were recruited from two urban and two suburban primary care clinics that provide care to underserved patients, many of whom do not have health insurance. Two recruitment methods were used at both clinics: flyers posted near the reception desk and direct invitation by a research assistant in the waiting
Participants
All patients who were approached appeared to have sufficient cognitive function to provide informed consent and sufficient ability to interact with the touchscreen computer [2]. No patients were excluded based on an inability to provide consent or interact with the computer. Enrollment rates were very high at both the suburban (90.3%) and urban (90.0%) sites. For those who chose not to participate, the primary reason given was not enough time to complete the assessment. Overall Mini-cog
Cognitive impairment
The proportion of participants who screened positive for cognitive impairment by the Mini-Cog in our study was 20.6%, which is quite high considering that the prevalence of dementia in the general population as determined by the Mini-Cog is only 6.4% [15]. Performance on tests of cognitive function may vary with social conditions over the lifecourse or by race/ethnicity, educational attainment, education quality, and literacy skills [22], [23], [24]. It is possible that in a vulnerable
Role of funding
This study was supported in part by Grant Number R01-HL081485 from the National Heart, Lung, and Blood Institute. Portions of this manuscript were presented at the Health Literacy 2nd Annual Research Conference, Bethesda MD, October 18–19, 2010.
Conflicts of interest
No conflicts of interest were reported by any of the authors.
Acknowledgements
The authors thank Katy Wortman for data management; Patricia O’Neil and Lindsay Norgaard for scoring the Mini-Cog clock drawings; Seung Choi, Jeremiah Aakre, Shane Pankratz and Paul Novotny for statistical analysis support; and David Eton for reviewing an earlier version of this manuscript. Finally, we thank all of the patients who participated in this study.
References (40)
- et al.
Bilingual health literacy assessment using the Talking Touchscreen/la Pantalla Parlanchina: development and pilot testing
Patient Educ Couns
(2009) - et al.
In search of ‘low health literacy’: threshold vs. gradient effect of literacy on health status and mortality
Soc Sci Med
(2010) - et al.
Precision of health-related quality-of-life data compared with other clinical measures
Mayo Clin Proc
(2007) - et al.
Literacy skills and communication methods of low-income older persons
Patient Educ Couns
(1995) - et al.
Sensitivity and specificity of standardized screens of cognitive impairment and dementia among elderly black and white community residents
J Clin Epidemiol
(1990) - et al.
Dementia risk prediction: are we there yet?
Clin Geriatr Med
(2010) - et al.
Health Literacy Assessment Using Talking Touchscreen Technology (Health LiTT): a new item response theory-based measure of health literacy
J Health Commun
(2011) - et al.
Acceptability of the talking touchscreen for health literacy assessment
J Health Commun
(2010) - et al.
“Health Literacy Assessment Using Talking Touchscreen Technology” (Health LiTT) is a valid measure of health literacy
- et al.
Introduction to classical and modern test theory
(1986)