FUNDAMENTAL INTERVENTION DELIVERY CHARACTERISTICS
There are numerous issues that need to be resolved when designing the content of the intervention including the actual material/topics covered in the intervention, the number of components of the intervention (single vs. multicomponent), the structure of the intervention (e.g., order in which the topics are presented), the mechanisms of action (e.g., interactive skill building vs. instruction), and degree of flexibility/adaptability. Other issues relate to equipment and material requirements, feasibility, and participant burden (Table 5.1). Importantly, these issues need to be resolved for all of the conditions in a trial/intervention including control conditions.
The content of an intervention is the “active ingredient of an intervention” and should be shaped by consideration of a number of factors including the theory/ conceptual framework guiding the intervention, prior research, the research questions, the target population of the intervention (e.g., individual, family) and associated characteristics, the stage of intervening (e.g., prevention, disease management), the area targeted (e.g., knowledge, skills, or the physical environment), and the intervention context. Other factors to consider are logistical problems as well as cost constraints and whether the treatment can be followed or replicated by others.
The theory guiding the intervention and prior research conducted in an area, as discussed earlier, helps to identify potentially malleable factors that may lead to changes in outcomes as well as mechanisms of action that are effective in realizing this change (Gitlin et al., 2000). The relationship between the means, ends, and intervening processes of a treatment in relation to the topic of interest or clinical problem needs to be clearly articulated (Kazdin, 1994). As discussed in previous chapters, the content and delivery characteristics of the Resources for Enhancing Alzheimer’s Caregiver Health (REACH) II intervention (Belle et al., 2006) are shaped by a variant of the stress process model, the findings from REACH I, and principles of adult learning. The stress process model suggests that multiple factors contribute to caregiver burden and distress. Findings from the REACH I trial (Gitlin et al., 2003) indicated that active interventions were superior and that interventions should be tailored to the characteristics of the caregiver. The adult-learning literature also indicates that active learning approaches are superior, learning should take place in the context in which the new skills are applied, and education and skills are adopted when perceived as needed. Thus, the REACH II was multicomponent, delivered in the home, was tailored to the needs of the caregiver using a risk appraisal approach, involved a variety of mechanisms of action that actively engaged the caregiver (e.g., problem solving and skill building), and was matched to the treatment component and targeted trial outcomes. Other decisions regarding the intervention content in REACH II were related to the number and ordering of the intervention sessions, the nature of the handout materials, and the parameters around adaptability (e.g., what aspects of the intervention could be adapted such as delivery location, and who could make decisions about adaptability). Similar decisions had to be made for the content of the information-only control group condition.
In the Personal Reminder Information System Management (PRISM) trial (discussed previously) (Czaja et al., 2015), decisions concerning the delivery characteristics of the intervention concerned which features to include on the software system (e.g., e-mail, community resources) as well as the names, content, and structure of the features. For the Internet feature, a decision had to be made about whether access should be restricted to websites preselected by the research team or if the participants should have unrestricted access. In the end, the decision was made to support unrestricted access; however, a tab was included within this feature that included links to websites that the investigative team thought would be of particular relevance to the participants. The classroom feature was dynamic and contained scripted information, vetted videos, and links to other sites on a broad array of topics (e.g., cognitive health, traveling tips, nutrition). New material was placed in the classroom every month and remained in the “classroom library.” In the design of this feature, specific decisions had to be made about the 12 monthly topics to be included, the order of the topics, the content for the topics, and the depth and literacy level of the information provided. The investigative team also had to select links to other sources of information and videos related to the featured monthly topic. In addition, similar materials had to be prepared for and delivered to those assigned to the attention control condition. Overall, the design and tailoring of the PRISM system and the material for the control condition were based on the available literature, the experience of the investigators, and knowledge about the characteristics of the target population and usability testing.
In all cases, it is important to pilot test the content of the intervention and the format in which it is delivered to receive input from other members of the research team as well as the targeted group. The content can also be shaped by input from members of a Community Advisory Board (CAB), Data Safety and Monitoring Board (DSMB), and a Scientific Advisory Board (SAB). The CAB can provide valuable advice about the relevance of the content for the target population and issues regarding feasibility. The DSMB is likely to provide input on issues related to participant burden, and an SAB might provide new ideas on topics, methods of treatment delivery, or challenges that might arise in the course of a trial based on the best evidence to date. As noted, the development of an intervention is an iterative process, and the content of an intervention should be refined through various feedback mechanisms and a purposeful, thoughtful approach.