| MEASUREMENT PROPERTIES | |
| Limitations | |
| Observations | |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Internal consistency (Cronbach’s α) was 0.99 (19 items) in the original validation and 0.89 (17 items) in the subsequent evaluation by Menz et al. Cronbach’s α values of 0.74, 0.92, and 0.77 have been reported for the pain intensity, functional limitation, and appearance domains, respectively |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
Test‐retest repeatability for disabling foot pain was poor for pain intensity, fair for functional limitation, and good for appearance (κ = 0.34, 0.57, and 0.61, respectively) when problems were required to occur on at least some days in the last month, and it was fair for pain intensity (0.55), good for functional limitation (0.72), and poor for appearance (0.34) at the more stringent cutoff of most days/every day |
| 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) |
Content validity was achieved by interviewing patients attending foot clinics about pain, disability, activity limitation, and footwear.
|
| B. Construct Validity: Structural validity |
Not Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description | |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Criterion validity has not been evaluated because of the absence of a gold standard measure of foot pain or function. |