The Caregiver Contribution to Heart Failure Self‐Care (CACHS): Further Psychometric Testing of a Novel Instrument
Self‐care is defined most simply as the consistent activities that people perform to maintain their own lives and lifestyles (Orem, Renpenning, & Taylor, 2003). Chronic illness self‐care is conceptualized as a three‐step process: (1) maintaining health (self‐care maintenance); (2) monitoring for changes in health (self‐care monitoring); and (3) managing those changes if and when they occur (self‐care management; Riegel, Jaarsma, & Stromberg, 2012). For one common chronic illness, heart failure (HF), adequate self‐care has been linked to positive outcomes such as lower inpatient costs (Riegel et al., 2012) and event‐free survival (Lee, Moser, Lennie, & Riegel, 2011). However, in an analysis of HF self‐care data across 15 countries, patients’ self‐care was generally inadequate (Jaarsma et al., 2013), and over half of HF patients struggled with exercise, weight monitoring, obtaining preventive treatments (i.e., flu shots), and following a low‐sodium diet. Living with and managing complex chronic illness is hard work, and patients need more support (Gallacher, May, Montori, & Mair, 2011; Jowsey, Yen, & Matthews, 2012; Sav et al., 2013).
CGs are well‐positioned to provide needed support by virtue of their relationship and proximity to the patient. Activating CGs to supplement patient self‐care has been suggested as a means to address self‐care deficits (Buck, Mogel, Riegel, McMillan, & Bakitas, 2015). However, in the few reports to date, CGs’ scores were as low as were patients’ on their contributions to HF self‐care (Bidwell et al., 2015; Lee et al., 2014). These results suggest that further study is needed to better understand predictors, mediators, and moderators of CGs’ contributions to HF self‐care. However, a challenge to moving forward is the lack of a comprehensive measurement tool derived from the CG perspective. Previous attempts to address this limitation have involved the use of an instrument developed for another purpose, such as the Oberst Caregiving Burden scale, to quantify specific activities (Pressler et al., 2009), or adaptation of a patient‐based instrument (Vellone et al., 2013). However, the use of such proxies has not allowed for clear distillation of CG contributions and its impact on patient‐reported outcomes.
The purpose of this study was to conduct psychometric testing and item reduction on the recently developed Caregiver Contribution to Heart Failure Self‐care (CACHS) instrument. Grounded in the Theory of Self‐care in Chronic Illness (Riegel et al., 2012), the CACHS tool we originally developed consists of 34 CG self‐care items that capture CG contributions to self‐care maintenance, monitoring and management. We used accepted instrument development and testing processes, in three steps: (1) item development; (2) item clarification; and (3) item reduction (Guyatt, Kirshner, & Jaeschke, 1992; Juniper, Guyatt, Willan, & Griffith, 1994; Kirshner & Guyatt, 1985). Steps 1 and 2 were previously completed (Table 1) and reported previously (Buck et al., 2014; Harkness et al., 2015). This paper reports the outcomes of Step 3, item reduction.