VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations >=5 European languages (English)
Observations

Ritter and Lorig (2014) conducted two new studies and reviewed eight independent studies to investigate the psychometric properties of the scale. This report of psychometric properties of the English- and Spanish-language Self-Efficacy for Managing Chronic Disease scales (SEMCD and SEMCD-S).

A German version and 4-item Spanish version are also available.

The completion rates (completing at least two third of the items) for the SEMCD and SEMCD-S were high, varying from 98.7% to 100%.

1. RELIABILITY
A. Internal Consistency Tested
Cronbach's (Describe)

Cronbach's alpha was a minimum of .88 across all studies.

B. Reliability intraobserver or test-retest Tested
Continuous scores: intraclass
correlation coefficient (ICC)
Dichotomus: Cohen kappa (Describe)

Test-retest reliability was estimated which revealed a high interclass correlation coefficient (ICC = 0.87-0.997).

C. Reliability interobserver or Measurement error Not Tested
Standard error of measurement (SEM),
smallest detectable change (SDC) or
Limits of agreement (LoA) (Describe)
2. VALIDITY
A. Content validity: face validity Tested
Expert opinion (relevance and
comprehensiveness) (Describe)

The content validity of the SEMCD was interpreted as satisfactory.

B. Construct Validity:
Structural validity
Tested
Hypotheses-testing Tested
Cross-cultural validity Tested
Brief Description

Requiring a minimum eigenvalue of 1.0 resulted in only a single component being generated for both scales. If a second component were forced, eigenvalue for those components would be 0.713 for the SEMCD and 0.276 for the SEMCD-S. When principal component analyses were performed within each study separately, only a single factor was generated in all eight studies. In none of the eight studies was the eigenvalue for a second component as great as 0.8.

C. Criterion validity Tested
Comparison with a 'gold standard' Continuous scores:
correlations, ROC curves Dichotomus:
Sensitivity & Specificity (Describe)

No gold standard for self-efficacy available.