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Table 1 Primary and secondary outcome measures and study variables in the iSupport online support trial

From: iSupport, an online training and support program for caregivers of people with dementia: study protocol for a randomized controlled trial in India

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

  
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  8. gTeri L, Truax P, Logsdon R, Uomoto J, Zarit S, Vitaliano PP. (1992). Assessment of behavioral problems in dementia: The Revised Memory and Behavior Problems Checklist (RMBPC). Psychology and Aging. 7(4):622–31.
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