VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations English only
Observations
1. RELIABILITY
A. Internal Consistency Not Tested
Cronbach's (Describe)
B. Reliability intraobserver or test-retest Tested
Continuous scores: intraclass
correlation coefficient (ICC)
Dichotomus: Cohen kappa (Describe)

ICC = 0.87 (good) for 20 day test-retest interval for women with hip disorders. ICC 0.77 for chronic low back pain.

C. Reliability interobserver or Measurement error Tested
Standard error of measurement (SEM),
smallest detectable change (SDC) or
Limits of agreement (LoA) (Describe)

SEM= 0.86 in  cohort of elderly adults

2. VALIDITY
A. Content validity: face validity Not Tested
Expert opinion (relevance and
comprehensiveness) (Describe)
B. Construct Validity:
Structural validity
Not Tested
Hypotheses-testing Tested
Cross-cultural validity Not Tested
Brief Description
C. Criterion validity Tested
Comparison with a 'gold standard' Continuous scores:
correlations, ROC curves Dichotomus:
Sensitivity & Specificity (Describe)

No true gold standard in assessing physical function exists.  In analysis for validity, there was a significant but low to moderate correlation between step counts and 3 BQ subscales (rho, 0.30-0.49) and a higher correlation between step counts and total score (rho, 0.49). 

Excellent correlation between 24 hour recall of activity and total score (r= 0.78) and between step counts and total score (r= 0.72).

Correlation to accelerometer = 0.49 (good)