Development and validation of the comprehensive health activities scale: a new approach to health literacy measurement.

ABSTRACT

Current health literacy measures have been criticized for solely measuring reading and numeracy skills when a broader set of skills is necessary for making informed health decisions, especially when information is often conveyed verbally and through multimedia video. The authors devised 9 health tasks and a corresponding 190-item assessment to more comprehensively measure health literacy skills. A sample of 826 participants between the ages of 55 and 74 years who were recruited from an academic general internal medicine practice and three federally qualified health centers in Chicago, Illinois, completed the assessment. Items were reduced using hierarchical factor analysis and item response theory resulting in the 45-item Comprehensive Health Activities Scale. All 45 items loaded on 1 general latent trait, and the resulting scale demonstrated high reliability and strong construct validity using measures of health literacy and global cognitive functioning. The predictive validity of the Comprehensive Health Activities Scale using self-reported general, physical, and mental health status was comparable to or better than widely used measures of health literacy, depending on the outcome. Despite comprehensively measuring health literacy skills, items in the Comprehensive Health Activities Scale supported 1 primary construct. With similar psychometric properties, current measures may be adequate, depending on the purpose of the assessment.