An important distinction needs to be made between intervention components and implementation components. Intervention components (usually studied in efficacy or effectiveness studies under controlled conditions) are aspects of the intervention designed to create change (e.g., to improve patient-level symptoms and functioning). Implementation components refer to the elements needed to implement the core intervention components and to enhance acceptability and feasibility of a new evidence-based practice in a real setting (Fixsen, Naoom, Blase, Friedman, & Wallace, 2005). Implementation is defined as “a set of activities designed to put into practice” an intervention program (Fixsen et al., 2005). For example, the core intervention components of the chronic care model include a patient registry and self-management strategies (Wagner, Austin, & Von Korff, 1996); the implementation components concern how those components are carried out in clinical or community settings. Important aspects of implementation may include practitioners’ attitudes toward changing their care practices and the willingness of organizational leadership to adopt an intervention.
In implementation, quantitative methods are commonly used to study outcomes while qualitative methods are used to understand process (Palinkas et al., 2011). Process involves understanding what actually happens in practice settings when an intervention is implemented, for which qualitative methods are well suited because of the focus on gaining the perspective of people in the practice setting. Failure to adapt treatments in ways that increase organizational and community “fit” may explain why research-proven interventions are often not disseminated or maintained (Hoagwood, Burns, & Weiss, 2002). When developing behavioral strategies and putting interventions into practice, mixed methods provide a framework to ensure that the interventions incorporate real-world concerns. Mixed methods inform several implementation issues: how to adapt an intervention to a specific context, what strategies are used to implement interventions in practice settings, and how elements of the implementation strategy influence patient-centered outcomes.
An example of using mixed methods through implementation of an intervention comes from a study of the development, testing, and scale-up of an integrated care management of type 2 diabetes and depression program aimed at improving medical adherence (Bogner, Morales, de Vries, & Cappola, 2012). Initial qualitative interviews with patients and families indicated how to adapt Wagner Chronic Care Model to incorporate core intervention components needed for patients with diabetes and depression comorbidity. A RCT was then used to test the efficacy of the integrated care intervention in improving adherence to medication treatment. Furthermore, focus groups and semistructured interviews were employed to assess interventionists’ views on the successes and challenges of the intervention as well as organizational factors (e.g., cost-effectiveness and hospital administrators’ attitudes concerning the intervention) that served as important implementation factors for the scalability of the intervention. Mixed methods were also used to identify policy- and environmental-level factors that influence maintenance and sustainability of an integrated care intervention in a health care setting. All of these efforts toward careful development of intervention and implementation components using mixed methods led to improved patient outcomes not only in the research trials but also in practice settings.