Comparison of reliability and efficiency of two modified two-point discrimination tests and two-point estimation tactile acuity test

Objectives: Determine reliability and minimal detectible difference of two modified two-point discrimination (TPD) testing methods and explore reliability of newer tactile acuity test, two-point estimation (TPE) method. Design: Non-experimental observational reliability study. Setting: Community. Participants: Thirty-five (female = 25) healthy individuals average age 27.7 years (SD = 9.7). Intervention: Two modified methods (i.e., descending-ascending and descending with randomization) of TPD testing utilizing decreased runs of descending and ascending measurements were tested for inter-rater reliability and efficiency between two testers at three locations (neck, hand, and foot). The newer tactile acuity test of TPE was also performed between both examiners at the three location sites. Results: Inter-rater reliability (ICC 2, k) for the descending-ascending method was 0.75, 0.79, and 0.67 for the neck, hand, and foot, respectively. For the descending with randomization method, ICC values were 0.74, 0.50, and 0.69 for the three body regions respectively. The minimal detectable difference for the neck was 28.8 and 32.7 mm, hand 5.3 and 10.8 mm, and foot 12.3 and 12.4 mm for the descending-ascending and randomization methods. TPE showed poor reliability for neck and hand (0.27 and 0.15), but moderate reliability for the foot (0.67). Time to perform the TPD test were between 54 and 108 seconds, while TPE was 12 seconds. Conclusion: The modified TPD testing methods demonstrated similar reliability to previous research, even with reduced runs allowing for increased efficiency in performing the test. The TPE method showed poor reliability, so caution should be applied when using this method.