Man Hung1, Christine Cheng2, Shirley D Hon3, Jeremy D Franklin4, Brandon D Lawrence2, Ashley Neese2, Chase B Grover2, Darrel S Brodke2. 1. University of Utah School of Medicine, Department of Orthopaedics, Department of Public Health, Division of Epidemiology, Huntsman Cancer Institute, 590 Wakara Way, Salt Lake City, UT 84108, USA. Electronic address: Man.Hung@hsc.utah.edu. 2. University of Utah School of Medicine, Department of Orthopaedics, 590 Wakara Way, Salt Lake City, UT 84108, USA. 3. University of Utah College of Engineering, Department of Electrical and Computer Engineering, 50 S. Central Campus Dr., Rm. 3280 MEB, Salt Lake City, 84112, UT, USA. 4. University of Utah College of Education, Salt Lake City, UT, USA.
Abstract
BACKGROUND CONTEXT: The neck disability index (NDI) was the first patient-reported outcome (PRO) instrument specific to patients with neck pain, and it remains one of the most widely used PROs for the neck population. The NDI is an appealing measure as it is a short and well-known PRO measure. Currently, there are conflicting data on the performance and applicability of the NDI in patients undergoing either operative or nonoperative treatment for neck-related conditions. PURPOSE: This study investigates the psychometric properties, performance, and applicability of the NDI in the spine patient population. STUDY DESIGN: A total of 865 patients visiting a university-based spine clinic with neck complaints, with or without radiating upper extremity pain, numbness, or weakness were enrolled in the study. Visit types included new and follow-up visits to both operative and nonoperative treatments. Questionnaires were administered electronically on a tablet computer, and all patients answered all 10 questions of the NDI. METHODS: Standard descriptive statistics were performed to describe the demographic characteristics of the patients. Rasch modeling was applied to examine the psychometric properties of the NDI. RESULTS: The NDI demonstrated insufficient unidimensionality (ie, unexplained variance after accounting for the first dimension=9.4%). Person reliability was 0.85 and item reliability was 1.00 for the NDI. The overall item fit for the NDI was good with an outfit mean square of 1.03. The NDI had a floor effect of 35.5% and ceiling effect of 4.6%. The raw score to measure correlation of the NDI was 0.019. CONCLUSIONS: Although the NDI had good person and item reliability, it did not demonstrate strong evidence of unidimensionality. The NDI exhibited a very large floor effect. Because of the poor raw score to measure correlation, the sum score should not be used in interpretation of findings. Despite great investment by physicians and other stakeholders in the NDI, this evaluation and previous research have demonstrated that the NDI needs further investigation and refinement.
BACKGROUND CONTEXT: The neck disability index (NDI) was the first patient-reported outcome (PRO) instrument specific to patients with neck pain, and it remains one of the most widely used PROs for the neck population. The NDI is an appealing measure as it is a short and well-known PRO measure. Currently, there are conflicting data on the performance and applicability of the NDI in patients undergoing either operative or nonoperative treatment for neck-related conditions. PURPOSE: This study investigates the psychometric properties, performance, and applicability of the NDI in the spine patient population. STUDY DESIGN: A total of 865 patients visiting a university-based spine clinic with neck complaints, with or without radiating upper extremity pain, numbness, or weakness were enrolled in the study. Visit types included new and follow-up visits to both operative and nonoperative treatments. Questionnaires were administered electronically on a tablet computer, and all patients answered all 10 questions of the NDI. METHODS: Standard descriptive statistics were performed to describe the demographic characteristics of the patients. Rasch modeling was applied to examine the psychometric properties of the NDI. RESULTS: The NDI demonstrated insufficient unidimensionality (ie, unexplained variance after accounting for the first dimension=9.4%). Person reliability was 0.85 and item reliability was 1.00 for the NDI. The overall item fit for the NDI was good with an outfit mean square of 1.03. The NDI had a floor effect of 35.5% and ceiling effect of 4.6%. The raw score to measure correlation of the NDI was 0.019. CONCLUSIONS: Although the NDI had good person and item reliability, it did not demonstrate strong evidence of unidimensionality. The NDI exhibited a very large floor effect. Because of the poor raw score to measure correlation, the sum score should not be used in interpretation of findings. Despite great investment by physicians and other stakeholders in the NDI, this evaluation and previous research have demonstrated that the NDI needs further investigation and refinement.
Authors: Barrett S Boody; Surabhi Bhatt; Aditya S Mazmudar; Wellington K Hsu; Nan E Rothrock; Alpesh A Patel Journal: J Neurosurg Spine Date: 2018-01-05
Authors: Richard Kendall; Bill Wagner; Darrel Brodke; Jerry Bounsanga; Maren Voss; Yushan Gu; Ryan Spiker; Brandon Lawrence; Man Hung Journal: Pain Med Date: 2018-09-01 Impact factor: 3.750
Authors: Man Hung; Charles L Saltzman; Richard Kendall; Jerry Bounsanga; Maren W Voss; Brandon Lawrence; Ryan Spiker; Darrel Brodke Journal: Clin Orthop Relat Res Date: 2018-10 Impact factor: 4.176
Authors: Man Hung; Charles L Saltzman; Maren W Voss; Jerry Bounsanga; Richard Kendall; Ryan Spiker; Brandon Lawrence; Darrel Brodke Journal: Spine J Date: 2018-06-30 Impact factor: 4.166
Authors: Dhruv K C Goyal; Hamadi A Murphy; Douglas A Hollern; Srikanth N Divi; Kristen Nicholson; Christie Stawicki; I David Kaye; Gregory D Schroeder; Barrett I Woods; Mark F Kurd; Jeffrey A Rihn; D Greg Anderson; Christopher K Kepler; Alan S Hilibrand; Alexander R Vaccaro; Kristen E Radcliff Journal: Int J Spine Surg Date: 2020-02-29
Authors: Anita Gross; Theresa M Kay; Jean-Philippe Paquin; Samuel Blanchette; Patrick Lalonde; Trevor Christie; Genevieve Dupont; Nadine Graham; Stephen J Burnie; Geoff Gelley; Charles H Goldsmith; Mario Forget; Jan L Hoving; Gert Brønfort; Pasqualina L Santaguida Journal: Cochrane Database Syst Rev Date: 2015-01-28