COGNITIVE AND FUNCTIONAL OUTCOMES: THE ROLE OF OBJECTIVE MEASUREMENT
PHILIP D. HARVEY
To understand how [people] really think and feel, it is vital to go beyond words.
Many behavioral intervention studies are aimed at increasing cognitive and functional skills, with the eventual goal of improving everyday functioning, subjective quality of life, and lessening care needs. Target populations may include healthy older adults, older adults with chronic conditions and impairments, and individuals with disabling conditions such as neuropsychiatric disorders (e.g., schizophrenia). The focus of this chapter is on measures specific to intervention studies that are designed to impact cognitive and functional domains of everyday living. A focused discussion on these two domains of outcomes is warranted as there is a vast and emerging literature on this topic and cognition and functional independence is of increasing concern, particularly with the aging of the population.
As noted in Chapter 14, the choice of outcome measures for behavioral intervention trials is an important issue as it has a significant influence on many aspects of the study design and the evidence regarding the impact of the intervention. Researchers conducting intervention trials aimed at cognitive and functional performance are faced with a myriad of choices as there are several different strategies for collecting outcomes data for these types of intervention studies. These strategies include informant reports, self-reports, standardized neuropsychological tests, observational strategies, and objective indices of functional performance. Each of these measures provides different insights into the impact of an intervention and has associated strengths and weaknesses. Although a brief overview of the myriad of measures used is provided, the emphasis in this chapter is on objective performance-based measures.
We begin the chapter with rationale for the importance of performance-based measures and the shortcomings of self-report, followed by a brief overview of the construct of cognition and how it is distinct from functional performance. We then briefly discuss the strengths and weaknesses of self-report and informant-based measures as this topic was covered in the prior chapter. In the sections that follow, we describe the different types of objective performance-based assessments, the distal targets of these interventions, and the strengths and limitations of each approach. Finally, strategies for obtaining optimal assessment data are presented.