Shape-texture-identification—STI—A test for tactile gnosis: Concurrent validity of STI²

Study Design: Cross-sectional study. Introduction: The shape-texture-identification (STI) test (Össur Nordic AB, Sweden) is used to evaluate one aspect of tactile gnosis in nerve disorders, and it has proven good methodological properties. Purpose of the Study: A new version of the STI test was recently introduced—STI² (www.sensory-test.com). The purpose of this study was to test the concurrent validity in STI². Methods: Using a cross-sectional design, this methodological study compared STI² to the original version based on 2 cohorts; 1 including 20 persons (1 affected finger and corresponding finger on in opposite hand) with affected sensibility after hand injuries and 1 healthy group including 20 persons (digits II and V in both hands). The agreement between the 2 versions of the instrument was calculated statistically by a percentage comparison of the test results and weighted kappa. Results: The 112 tested fingers showed a complete agreement, or 1-point accepted deviation, between the 2 tests in 92% with weighted kappa of 0.74 and 95% confidence interval of 0.63-0.89. The result showed that there is no significant deviation between the 2 versions of the test. Discussion: The use of standardizes and evidence based assessment tools in clinical practice is paramount for a patient centered healthcare. Previous research has shown good psychometric proprties in the STI-test. This study contributes to the scientific evidence of the instrument. Conclusion: As the new STI² proved good agreement within the accepted deviation, we conclude that there is evidence to use the new STI² test in assessment of tactile gnosis.