Outcome measures in the randomized controlled trial (RCT) (number of items, response scale, total scale score range) | ||||||
---|---|---|---|---|---|---|
Primary | Target of scale | Reliability and validity of scales | Cronbach’s alpha | Pre measurement (T0) | First Follow up (T1) | Second Follow-up (T2) |
Zarit Burden Scale (22, 0–4, 0–88)a | Perceived stress of caregiving | Intra-class correlation coefficient (ICC): 0.88 to 0.89 | Cronbach’s α = 0.82 to 0.93 | X | X | |
CES-D10 Center for Epidemiological Studies Depression Scale (10 items, 0–3, 0–30)b | Depression | Test-retest reliability (r values = 0.41 to 0.70) | Cronbach’s α = 0.80 to 0.85 | X | X | X |
GAD Generalized Anxiety Disorder 7-item scale (7 items,0–3, 0–21)c | Anxiety | ICC = 0.83 | Cronbach’s α = 0.92 | X | X | |
Secondary | ||||||
EuroQoL-5D Descriptive system of health-related quality of life states consisting of 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression).d | Quality of Life | ICC = 0.70 | No overall Cronbach's α reported | X | X | |
Mastery (7 items, 1–4, 7–28)e | Perlin 7-item Mastery Scale | Principal component factor loadings ranging from − 0.47 to 0.76 | X | X | ||
Self-efficacy (1, 0–5, 0–40)f | RIS Self-efficacy Scale | r = 0.48 to 0.69 | Cronbach’s α = 0.72 to 0.79 | X | ||
Confounders/modifying Variables | ||||||
Behavioral Problems RMBPC (6, 0–4, 0–24)g | Revised Memory and Behavioral Problems Checklist | Rs = 0.29, .31, .26; ps < .01 correlations between subscales and caregiver depression (CES-D) and burden (Caregiver Stress Scale) | Cronbach’s α values are: .75 for frequency and .76 for reaction for memory problems .82 and .77 for depression and .62 and .70 for disruptive behavior | X | X | |
Functional status of person with dementia ADh | Informant Questionnaire on Cognitive Decline in older people (AD8) | r = 0.75 | Cronbach’s α = 0.84 | X | X | |
Demographic variables caregiver’s age, caregiver sex, relationship to the person with dementia (spouse, adult child, or other family member), level of education, living arrangement (living together or apart from the person with dementia) | X |