VALIDATION DATA

MEASUREMENT PROPERTIES
Limitations <5 European languages (English)
Observations
1. RELIABILITY
A. Internal Consistency Tested
Cronbach's (Describe)

The principal component analysis revealed the greatest eigenvalue was less than 3 for both scales (2.4 and 2.5), supporting the unidimensionality of the scale, with 54.8% (48.1%) of the variance in the data explained by the model.

Internal consistency of the IPEQ as a whole was low but acceptable with Cronbach’s alpha of 0.60 and 0.61.

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

Test–retest reliability was assessed by the ICC between scores obtained in the initial survey and at one week follow-up. The IPEQ had excellent test-retest reliability, intraclass correlation coefficient 0.87

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 Not Tested
Expert opinion (relevance and
comprehensiveness) (Describe)
B. Construct Validity:
Structural validity
Tested
Hypotheses-testing Not Tested
Cross-cultural validity Not Tested
Brief Description

Planned physical activity scores were significantly lower in older participants, in people with worse health and a worse score on the timed up-and-go test. The two versions of the test were compared using non-parametric Spearman correlations. Overall, the correlation was substantial to outstanding, ranging from 0.67 to 0.89, with a similar concurrent validity

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

The coefficients with accelerometer at low and medium cut points were 0.29 and 0.33, respectively, and 0.26 and 0.35 for walking. The Bland-Altman plot showed increased errors with higher values of IPEQ. IPEQ incidental physical activity questions and IPEQ as a whole were significantly correlated with accelerometer light intensity (100-760 counts per minute, ρ = 0.29 and 0.23).