Zarit Burden Interview

Cut Scores:

(Schreiner et al, 2006; stroke (n = 80) and COPD (n = 48); mean age for entire sample = 60 to 65 years; Japanese sample)

• A ZBI cut-off score that ranged from 24 to 26 identified caregivers in need of further assessment
• A ZBI cut-off of 25 correctly identified 77% of high burden stroke caregivers

Caregivers of individuals with Dementia: (Wang et al, 2008; n = 42; mean age = 66 (12.67) years; Chinese sample)

• Mean ZBI score = 24.40 (14.68) points 

Caregivers of individuals with Acute Stroke & COPD: (Schreiner et al, 2006)

• ZBI with stroke patients; mean score = 28.32 (12.7) points 
• ZBI with COPD patients; mean score = 20.35 (13)points
• ZBI among patients with General Disabilities; score = 30.34 (17.7) points

Caregivers of individuals with cancer, dementia and acquired brain injury: (Higginson et al, 2010; cancer (n= 105), dementia (n = 131), and acquired brain injury (n= 215); mean ages across samples range from 54 to 60 years)

Descriptive statistics of scores for six short-form and full-scale versions of the ZBI

Diagnosis

Version

Stats

Cancer

Dementia

ABI

ZBI-12

Mean (SD)

12.0 (8.5)

15.1 (10.0)

21.7 (10.1)

95% CI

10.4-13.7

13.4-16.8

20.4-23.1

ZBI-8

Mean (SD)

5.5 (4.7)

8.8 (6.1)

11.5 (7.2)

95% CI

4.6-6.4

7.7-9.8

10.5-12.4

ZBI-7

Mean (SD)

7.4 (5.6)

9.9 (6.8)

14.3 (7.0)

95% CI

6.3-8.5

8.7-11.1

13.4-15.3

ZBI-6

Mean (SD)

6.4 (4.9)

8.2 (5.8)

12.3 (6.0)

95% CI

5.4-7.3

7.2-9.2

11.5-13.1

ZBI-4

Mean (SD)

4.8 (3.5)

6.1 (4.1)

7.9 (3.8)

95% CI

4.2-5.5

5.4-6.8

7.3-8.4

ZBI-1

Mean (SD)

1.0 (1.2)

1.7 (1.3)

2.1 (1.3)

95% CI

0.8-1.3

1.5-2.0

1.9-2.2

ZBI-22

Mean (SD)

23.2 (13.4)

27.9 (16.4)

39.1 (17.3)

95% CI

20.7-25.8

25.0-30.7

36.8-41.4

Caregivers of Patients with Dementia: (Zarit et al, 1986; n = 64; mean male age = 72.27 (6.72), mean female age = 63.37 (7.48) years)

Interviewed at an initial interview then two years later:

At home

Nursing home

Deceased

Time 1

Time 2

Time 1

Time 2

Time 1

Burden

33.59

29.17

43.54

23.44

39.33

Mental status questionnaire

3.54

2.08

2.36

a

2.87

Frequency of memory and behavior problems

45.72

44.55

48.00

44.50

51.93

Cross product of memory and behavior problems

47.76

19.06

67.36

35.25

65.40

Formal / Informal social supports

12.25

11.70

11.36

12.71

11.00

Subjective social supports

2.22

2.72

1.64

0.75

1.87

Quality of prior relationship

8.35

--

7.64

--

6.67

a = patients in nursing homes were not tested at Time 2

Caregivers of individuals with Dementia: (Wang et al, 2008; n = 42; mean age = 66 (12.67) years; Chinese sample)

• Mean ZBI score = 24.40 (14.68) points 

All values = Mean (SD)

ZBI Meta Analysis: (Bachner & O'Rourke, 2007; n = 138 data points; mean age 73.64 (11.64) years)

• Coefficients differed as a function of time between assessments, however, this should not be seen as
  a limitation since caregiver burden should vary over time

Caregivers to Patients with Dementia: (Wang et al, 2008)

• Excellent Internal Consistency (alpha = 0.89)
• Excellent split half reliability = 0.87

Caregivers of individuals with Various Diagnoses: (Siegert et al, 2010; n = 222 caregiver of TBI, stroke, brain infection, hypoxia and other disorders; alpha for a two dimensional model)

• Excellent: Personal Strain factor (alpha = 0.82)
• Excellent: Role Strain factor (alpha = 0.80)

ZBI Meta Analysis: (Bachner & O'Rourke, 2007; n = 138 data points; mean age 73.64 (11.64) years)

• Excellent (overall alpha = 0.86)

Caregivers of individuals with Dementia: (Wang et al, 2008)

Concurrent Validity 

• Adequate; ZBI & The Geriatric Depression Scale 30 item Scale (r = 0.57  p < 0.001)
• Adequate; ZBI & The Hamilton Anxiety Scale (r = 0.44 p = 0.003)
• Adequate; ZBI & The Mini-Mental State Examination (r = -0.31 p = 0.044)

Dimensionality of the Zarit: (Siegert et al, 2010) Confirmatory Factor analysis resulted in 2 dimensions:

• Personal strain
• Role strain
• There was no evidence Differential Item Functioning for different types of carer or type of disorder

Review Article: (Visser-Meily et al, 2004)

• No change in perceived burden between 2 months and 2-4 years after stroke
• No change in perceived burden between 3 and 48 months after stroke