Psychometric Validation of the Cardiac Rehabilitation Barriers

Scale (CRBS)

Shamila Shanmugasegaram, MSc

CRCARE: Cardiac RehabCare Continuity through Automatic Referral

Evaluation

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Measuring CR Barriers

Patient, provider, and health system-level barriers to CR utilization have been identified (Grace et al., 2004)

To date, there are 3 validated scales assessing CR: Beliefs About Cardiac Rehabilitation (BACR) (Cooper et al.,

2007)

Cardiac Rehabilitation Preference Form - Revised (Fernandez et al., 2007)

Cardiac Rehabilitation Enrollment Obstacles (CREO) (Fernandez et al., 2008)

Two subscales: “Patient-related obstacles” and “Health service-related obstacles”

The purpose of this study is to psychometrically validate the CRBS

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CRBS: I did not attend a CR program, or if I did attend, I missed some sessions because: 1. …of distance (e.g., not located in your area, too far to travel)2. …of cost (e.g., parking, gas)3. …of transportation problems (e.g., access to car, public transportation)4. …of family responsibilities (e.g., caregiving)5. …I didn’t know about cardiac rehab (e.g., doctor didn’t tell me about it)6. …I don’t need cardiac rehab (e.g., feel well, heart problem treated, not serious)7. …I already exercise at home, or in my community8. …severe weather9. …I find exercise tiring or painful10. …travel (e.g., holidays, business, cottage)11. …of time constraints (e.g., too busy, inconvenient class time)12. …of work responsibilities13. …I don’t have the energy14. …other health problems prevent me from going15. …I am too old16. …my doctor did not feel it was necessary17. …many people with heart problems don’t go, and they are fine18. …I can manage my heart problem on my own19. …I think I was referred but the rehab program didn’t contact me20. …it took too long to get referred and into the program21. …I prefer to take care of my health alone, not in a group

(Grace et al., 2004; Grace et al., 2009a; Grace et al., 2009b)

• Rated on a 5-point Likert scale from 1=strongly disagree to 5=strongly agree

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Objectives

To investigate the:

1) Factor structure through factor analysis

2) Reliability

3) Criterion validity with regard to CR enrollment and participation

4) Convergent validity with an adapted version of the “practical barriers” subscale of the BACR scale and the CREO scale

5) Test-retest reliability

6) Socially-desirable responding

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Recruitment Flow Diagram

N=5781 Potential participants approached and assessed for eligibility from 11 hospitals from September

2006 to November 2008.

1439 (25%) ineligible 2658 participants 1684 (29%) declined

1410 participants 44 (3%) declined197 (14%) ineligible

Response rate to date: 61.2%

Retention rate to date: 61.8%

In-Hospital Survey

1-YR FU Survey

134 participants

3-WK Post-Test Survey

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Participants

Inclusion Criteria

Diagnosis of Acute Coronary Syndrome, heart failure, and/or valve replacement Undergone Percutaneous Coronary Intervention and/or Coronary Artery Bypass Graft surgeryEligibility for CR based on guidelines of the CACR

Exclusion Criteria (in-

hospital)

Participation in CR within the past 2 yearsSignificant orthopedic, neuromuscular, visual, cognitive or non-dysphoric psychiatric condition

Exclusion Criteria (1 year

follow-up)

Patient moved, so unable to contactToo ill to participateDeceased

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Participants Cont’d

Characteristics of participants at 1 year follow-up (n=1410)

Age (mean±SD) 65.6±10.4

Sex (% female) 338 (24.0)

Ethnocultural background (% minority) 209 (15.5)

Education (% greater than high school) 651 (47.8)

Employment (% full or part-time) 471 (34.8)

Family income (% $50,000 or more) 558 (49.1)

Marital status (% married) 1084 (77.8)

Rurality (% yes) 177 (12.6)

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Procedure & Measures

Assessment Point Measures

in-hospital

Sociodemographic data Medical data

1 year follow-up

CR utilization (self-report)CRBSMarlowe-Crowne Social Desirability Scale (MCSDS) (Leite & Beretvas, 2005)

3 week post-test

CRBSBeliefs Scale (BACR) (Cooper et al., 2007)

Enrollment Obstacles Scale (CREO) (Fernandez et al., 2008)

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Results - Mean Scores on CRBS Items

Item Mean SD

…I already exercise at home or in my community 2.58 1.39

…of distance 2.21 1.37

…travel 2.20 1.24

…of work responsibilities 2.13 1.22

…severe weather 2.10 1.22

…of cost 2.07 1.27

…I find exercise tiring or painful 2.03 1.14

…of time constraints 2.03 1.16

…I prefer to take care of my health alone 2.00 1.13

…other health problems prevent me from going 2.00 1.18

…I don’t need CR 1.99 1.19

…I don’t have the energy 1.95 1.10

…of family responsibilities 1.93 1.09

…I didn’t know about CR 1.93 1.27

…I can manage on my own 1.91 1.04

…of transportation problems 1.90 1.12

…my doctor didn’t feel it was necessary 1.89 1.08

…it took too long to get referred and into the program 1.88 1.05

…many people with heart problems don’t go to CR and they are fine 1.85 .99

…I think I was referred but the rehab program didn’t contact me 1.76 1.01

…I am too old 1.66 .87

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Factor Analysis

CRBS Item Loadings

Need/Health Care

Logistical

Work/Time

Comorbidities

…I don’t need CR .86 …I can manage on my own .83 …my doctor didn’t feel it was necessary .75 …many people with heart problems don’t go to CR and they are fine

.69

…I prefer to take care of my health alone .59 …I didn’t know about CR .54 …I already exercise at home or in my community .54 …I think I was referred but the rehab program didn’t contact me

.37

…it took too long to get referred and into the program .33 …of cost .87 …of transportation problems .86 …of distance .82 …of family responsibilities .54 …severe weather .53 …of work responsibilities .87 …of time constraints .78 …travel .31 …I don’t have the energy .66 …other health problems prevent me from going .60 …I find exercise tiring or painful .57 …I am too old .57

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Percentage of Variance, Eigenvalues, and Reliability of the CRBS Subscales Identified through Factor Analysis

% of Variance Eigenvalue Reliability

Need/Health Care 40.03 6.43 .90

Logistical 7.20 6.09 .88

Work/Time 4.77 4.15 .71

Comorbidities 4.10 4.72 .83

Total 56.10 -- .93

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Criterion Validity of the CRBS

Total/Subscale Enrollees Non-Enrollees

M SD M SD t

Total CR barriers 1.76 .68 2.47 .60 -14.75*

Need/Health Care 14.37 6.09 23.52 5.62 -21.89*

Logistical 9.32 4.86 12.02 4.85 -7.26*

Work/Time conflicts 6.32 3.05 6.39 2.67 -.35

Comorbidities/Functional status 6.88 3.36 9.06 3.63 -8.94*

Note. *p<.001

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Criterion Validity of the CRBS Cont’d

Total/Subscale Percentage of CR Sessions Attended

Total CR barriers -.36**

Need/Health Care -.34**

Logistical -.27**

Work/Time conflicts -.21**

Comorbidities/Functional status -.35**

Note. **p<.001; *p<.01

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Convergent Validity of the CRBS

Subscale Total Need/ Health Care

Logistical Work/Time Comorbidities

CREO patient .23* .08 .19* .33*** .19*

CREO health .27** .42*** .11 .02 .06

BACR practical .51*** .34*** .57*** .32*** .32***

Note. ***p<.001; **p<.01; *p<.05

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Test-Retest Reliability of the CRBS

Test-retest reliability of the CRBS was acceptable (r = .65; p < .001)

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Socially Desirable Responding

Total Social Desirability Scale was significantly related to total CRBS (r = -.08; p < .05)

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Limitations

Self-report data

Recall bias Time elapsed between in-hospital & 1 year follow-up

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Discussion

CRBS consists of 4 reliable subscales Consistent with previous samples tested by our group Wary of social desirability bias, although correlations low

Compared to the CREO Scale, the CRBS has several advantages: Validated in more domains

Used broader and larger cardiac sample than the CREO scale More types (convergent validity and test-retest reliability)

More detailed assessment of patient-level barriers than the CREO scale CRBS = 3 versus CREO = 1

Assesses both CR enrollment and participation barriers Barriers to participation in CR have not yet been tested for CREO

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Acknowledgments

Co-PIs: Dr. Sherry Grace & Dr. Donna E. Stewart

MSc Cttee: Dr. Lucia Gagliese, Dr. Veronica Jamnik, & Dr. Mary Fox

CRCARE Co-investigators: Terry Fair, Dr. Glenn Holder, Ms. Rimmy Kaur, Dr. Ellen Rukholm, Dr. David Alter, Dr. James Rush, Dr. Sonia Anand, Dr. Karen Williamson, Dr. Paula Harvey, Dr. Paul Oh, Dr. Steve Bunker, & Dr. Milan Gupta

Study coordinator: Lori Van Langen, MSc

Grace Lab

STUDENT FUNDING:

STUDY FUNDING: