Functional Capacity Measures
Because of our increased knowledge that real-world outcomes are affected by an array of factors other than cognitive abilities, interest has grown in the area of direct assessment of functional skills. Referred to as “functional capacity,” this is the process of assessing the ability to perform critical everyday living skills in simulation settings (Harvey et al., 2007). The ability to perform skilled acts can be contrasted with the actual likelihood of performing those acts (Depp et al., 2010; Mausbach et al., 2011) in real-world settings. Similar to standard neuropsychological measures, functional capacity measures do not rely on self-report, and can be evaluated for their psychometric and validity properties.
There is an array of performance-based measures of everyday functioning skills aimed at assessing skills in the domains of residential, social, and vocational functions (Mausbach, Harvey, Goldman, Jeste, & Patterson, 2007; Patterson et al., 2001; see Moore, Palmer, Patterson, & Jette, 2007 for a review). The majority of these procedures use realistic assessments of functional activities such as shopping, cooking, managing money, and social interactions. These are generally administered as interactive tests, with systematic administration of the stimuli, systematic scoring procedures, and normative standards. Thus, much like performance-based cognitive tests, they provide a repeatable index of skills competence that can be used as an outcome measure in behavioral intervention trials.
Other investigators have developed ecologically valid simulations of common technology-based work tasks (e.g., Czaja, Sharit, Ownby, Roth, & Nair, 2001; Sharit
& Czaja, 1999) and have also shown that while cognitive abilities are important to task performance, other factors such as prior technology experience and amount of task practice are also important predictors of performance. More recently, our group has developed a battery of computer-based simulations of common everyday activities such as use of an ATM, refilling a prescription, using a ticket kiosk, and medication management. Preliminary data indicate that these tasks are reliable and have construct and discriminant validity. They are also “ecologically valid” (Czaja, Harvey, & Lowenstein, 2014). However, like neuropsychological measures of cognition, issues associated with comprehensiveness, duration of the assessment, and practicality need to be considered. Also similar to cognitive assessments, the same caveats and concerns need to be applied to the computerized versions of functional capacity measures (Ruse et al., 2014).