VALIDATION DATA

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

Before the validation study, a patient and public involvement consultation session was conducted with the purpose of exploring strategies for improving the adherence of participants using the app during the study.

B. Construct Validity:
Structural validity
Tested
Hypotheses-testing Not Tested
Cross-cultural validity Not Tested
Brief Description

The step counts in the study with OApp™ demonstrated small correlations between change in steps at baseline and 2-month follow-up with global improvement overall and WOMAC function.

C. Criterion validity Not Tested
Comparison with a 'gold standard' Continuous scores:
correlations, ROC curves Dichotomus:
Sensitivity & Specificity (Describe)

There is no gold standard against which to assess criterion validity.