Judging Outcomes in Psychosocial Interventions for Dementia Caregivers: The Problem of Treatment Implementation

It is estimated that 4 million Americans suffer from Alzheimer’s disease and related disorders (ADRD), with 80% of these individuals living at home and being cared for by family caregivers (Czaja, Eisdorfer, & Schulz, 2000). The number of people with ADRD is expected to grow exponentially as the U.S. population ages (Schulz & O’Brien, 1994). Potential stressors associated with family caregiving are numerous and can include managing behavioral disturbances, attending to physical needs, and providing seemingly constant vigilance (Gold et al., 1995; Vitaliano, Russo, Young, Teri, & Maiuro, 1991; Wright, Clipp, & George, 1993). The effects of these stressors on family caregivers can be catastrophic. Family caregiving has been associated with increased levels of depression and anxiety as well as higher use of psychoactive medications, poorer self-reported physical health, compromised immune function, and increased mortality (Light, Niederehe, & Lebowitz, 1994; Schulz & Beach, 1999; Schulz, O’Brien, Bookwala, & Fleissner, 1995). Over the past 20 years, researchers have examined a plethora of psychosocial interventions aimed at alleviating distress associated with dementia caregiving. Intervention programs have included intensive personalized counseling, supportive group counseling, providing knowledge about ADRD through educational programs, specific therapeutic skills training, enhancing problem-solving skills, and teaching behavior management techniques (see reviews by Bourgeois, Schulz, & Burgio, 1996; Kennet, Burgio, & Schulz, 2000; Knight, Lutzky, & Macofsky-Urban, 1993; Toseland & Rossiter, 1989; Zarit & Teri, 1992). The conclusions from these reviews are varied. However, there is a growing consensus in the literature that interventions that are comprehensive, intensive, and individually tailored to caregivers’ needs are likely to be more effective than those lacking these characteristics (Haley, Ehrbar, & Schonwetter, 1997; Kennet et al., 2000; Mittelman, Ferris, Shulman, Steinberg, & Levin, 1996). Another conclusion of these reviews is that existing dementia caregiving intervention studies are fraught with methodological weaknesses that present threats to their internal validity, that is, their ability to infer that the intervention was related to therapeutic changes in caregiver and care recipient outcomes. These deficiencies include, but are not limited to, the use of weak experimental designs, problematic sampling and randomization strategies, and the use of inadequate outcome measures. In their review, Bourgeois and colleagues (1996) focused on the importance of describing treatment process variables and the lack of attention caregiving intervention researchers have devoted to describing these variables. The investigation and description of treatment process variables allows researchers to understand which aspects of the intervention are responsible for therapeutic change; this, in turn, can result in the development of more efficacious and efficient interventions. Much has been written over the past two decades on the therapeutic process, particularly surrounding psychotherapy outcome research. Early writings by Cook and Campbell (1979) and Sechrest and colleagues (Sechrest, West, Phillips, Redner, & Yeaton, 1979; Sechrest & Yeaton, 1981) helped focus researchers’ attention on critical process variables such as the quality of the therapeutic relationship (therapeutic alliance), the level of therapist skill, and treatment dosage. However, the sine qua non of investigating treatment process variables is the description in precise terms of what the intervention involved (i.e., the treatment components) and establishing through empirical means that the intervention was presented as intended. This is commonly referred to as establishing treatment integrity. In the absence of assessing treatment integrity, conclusions regarding treatment efficacy cannot be made with any confidence (Sechrest et al., 1979; Sechrest & Yeaton, 1981). However, over the past decade clinical researchers have come to recognize that establishing treatment integrity (i.e., that the treatment was delivered as intended), though necessary, is insufficient for asserting that an unbiased test of the treatment was conducted. The participant’s mastery of treatment (termed receipt) and the participant’s application of treatment beyond the boundaries of the therapy session (termed enactment) are no less critical (Lichstein, Riedel, & Grieve, 1994). Thus, the path of the independent variable (treatment) has been partitioned into three components—delivery, receipt, and enactment—and their summative impact on the client has been termed treatment implementation (TI). The purpose of this article is to discuss the importance of assessing and reporting treatment implementation in dementia caregiver intervention research. Although we focus on caregiver interventions, these issues have relevance to all geriatric intervention research (e.g., comprehensive geriatric assessment, psychosocial nursing home interventions). We propose Lichstein’s TI model (Lichstein et al., 1994) as a means of conducting unbiased tests of intervention efficacy, and we describe the efforts of the Resources for Enhancing Alzheimer’s Caregiver Health (REACH) cooperative group to apply this model in ongoing caregiver intervention trials. Lichstein’s approach was chosen because it is the only existing system for evaluating treatment along its entire path from presentation to the client to the client’s use of treatment in the natural environment.