“…Some studies may include care recipients with chronic illnesses such as Parkinson’s disease, heart conditions, or dementia in a single sample (e.g., Piercy, 2007). Others may focus solely on dementia (e.g., Celdrán et al, 2009; Celdrán, Triadó, & Villar, 2011; Creasey & Jarvis, 1989; Creasey, Myers, Epperson, & Taylor, 1989) and several do not specify the type of illness (e.g., Dellmann-Jenkins & Brittain, 2003; Shifren, 2008). However, failing to distinguish between different types of illness makes it difficult to interpret results.…”