Table 2. Inter-rater reliability of the NNHt and the FPI-6.
| Variables | Rater 1 | Rater 2 | Kw (95% CI)a | Observed agreement (%) | ICCs (95% CI) |
| mean ± SD (min to max) | mean ± SD (min to max) | ||||
| NNHt | 0.22 ± 0.05 (0.11–0.33) | 0.22 ± 0.04 (0.10–0.36) | 0.92 (0.87–0.94) | 99.60 | 0.98b (0.95–0.99) |
| FPI-6 | 4.50 ± 4.64 (−7–11) | 4.40 ± 4.67 (−7–11) | 0.94 (0.91–0.96) | 99.47 | 0.98c (0.96–0.99) |
| Agreement between rater 1 and rater 2 in each item of the FPI-6 | |||||
| Item 1: talar head palpation | 0.71 (0.68–0.75) | 97.47 | |||
| Item 2: lateral malleoli curvature | 0.76 (0.59–0.88) | 98.40 | |||
| Item 3: calcaneal inversion/eversion | 0.83 (0.78–0.84) | 98.93 | |||
| Item 4: talonavicular bulging | 0.73 (0.62–0.81) | 98.13 | |||
| Item 5: height and congruence of medial longitudinal arch | 0.94 (0.93–0.97) | 99.60 | |||
| Item 6: abduction/adduction of the forefoot on the rearfoot | 0.73 (0.67–0.85) | 98.93 | |||
NNHt: normalized navicular height truncated; FPI-6: foot posture index-6; min to max: minimum to maximum.
a Presented Weight Kappa with 95% confidence interval.
b Presented intraclass correlation coefficient [ICC (2,3)] with 95% confidence interval.
c Presented intraclass correlation coefficient [ICC (2,1)] with 95% confidence interval analyzed from the Rasch-converted total FPI-6 scores.