Charles Philip Gabel1, Antonio I Cuesta-Vargas2, Jason W Osborne3, Brendan Burkett4, Markus Melloh5. 1. Faculty of Science, Health and Education, Centre for Healthy Activities, Sport and Exercise, University of the Sunshine Coast, Sippy Downs Dve, Sippy Downs, Sunshine Coast Qld 4556 Australia. Electronic address: cp.gabel@bigpond.com. 2. Department of Psychiatry and Physiotherapy, Faculty of Medicine, Malaga University, SpainAvenida Estación de el Palo, Málaga, 29017 Spain. 3. Educational and Counseling Psychology, University of Louisville, 2323 S Brook St, Louisville, KY, 40208 USA. 4. Faculty of Science, Health and Education, Centre for Healthy Activities, Sport and Exercise, University of the Sunshine Coast, Sippy Downs Dve, Sippy Downs, Sunshine Coast Qld 4556 Australia. 5. Centre for Medical Research (CMR), Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Perth, Australia.
Abstract
BACKGROUND CONTEXT: The Neck Disability Index frequently is used to measure outcomes of the neck. The statistical rigor of the Neck Disability Index has been assessed with conflicting outcomes. To date, Confirmatory Factor Analysis of the Neck Disability Index has not been reported for a suitably large population study. Because the Neck Disability Index is not a condition-specific measure of neck function, initial Confirmatory Factor Analysis should consider problematic neck patients as a homogenous group. PURPOSE: We sought to analyze the factor structure of the Neck Disability Index through Confirmatory Factor Analysis in a symptomatic, homogeneous, neck population, with respect to pooled populations and gender subgroups. STUDY DESIGN: This was a secondary analysis of pooled data. PATIENT SAMPLE: A total of 1,278 symptomatic neck patients (67.5% female, median age 41 years), 803 nonspecific and 475 with whiplash-associated disorder. OUTCOME MEASURES: The Neck Disability Index was used to measure outcomes. METHODS: We analyzed pooled baseline data from six independent studies of patients with neck problems who completed Neck Disability Index questionnaires at baseline. The Confirmatory Factor Analysis was considered in three scenarios: the full sample and separate sexes. Models were compared empirically for best fit. RESULTS: Two-factor models have good psychometric properties across both the pooled and sex subgroups. However, according to these analyses, the one-factor solution is preferable from both a statistical perspective and parsimony. The two-factor model was close to significant for the male subgroup (p<.07) where questions separated into constructs of mental function (pain, reading headaches and concentration) and physical function (personal care, lifting, work, driving, sleep, and recreation). CONCLUSIONS: The Neck Disability Index demonstrated a one-factor structure when analyzed by Confirmatory Factor Analysis in a pooled, homogenous sample of neck problem patients. However, a two-factor model did approach significance for male subjects where questions separated into constructs of mental and physical function. Further investigations in different conditions, subgroup and sex-specific populations are warranted.
BACKGROUND CONTEXT: The Neck Disability Index frequently is used to measure outcomes of the neck. The statistical rigor of the Neck Disability Index has been assessed with conflicting outcomes. To date, Confirmatory Factor Analysis of the Neck Disability Index has not been reported for a suitably large population study. Because the Neck Disability Index is not a condition-specific measure of neck function, initial Confirmatory Factor Analysis should consider problematic neck patients as a homogenous group. PURPOSE: We sought to analyze the factor structure of the Neck Disability Index through Confirmatory Factor Analysis in a symptomatic, homogeneous, neck population, with respect to pooled populations and gender subgroups. STUDY DESIGN: This was a secondary analysis of pooled data. PATIENT SAMPLE: A total of 1,278 symptomatic neck patients (67.5% female, median age 41 years), 803 nonspecific and 475 with whiplash-associated disorder. OUTCOME MEASURES: The Neck Disability Index was used to measure outcomes. METHODS: We analyzed pooled baseline data from six independent studies of patients with neck problems who completed Neck Disability Index questionnaires at baseline. The Confirmatory Factor Analysis was considered in three scenarios: the full sample and separate sexes. Models were compared empirically for best fit. RESULTS: Two-factor models have good psychometric properties across both the pooled and sex subgroups. However, according to these analyses, the one-factor solution is preferable from both a statistical perspective and parsimony. The two-factor model was close to significant for the male subgroup (p<.07) where questions separated into constructs of mental function (pain, reading headaches and concentration) and physical function (personal care, lifting, work, driving, sleep, and recreation). CONCLUSIONS: The Neck Disability Index demonstrated a one-factor structure when analyzed by Confirmatory Factor Analysis in a pooled, homogenous sample of neck problem patients. However, a two-factor model did approach significance for male subjects where questions separated into constructs of mental and physical function. Further investigations in different conditions, subgroup and sex-specific populations are warranted.
Authors: Charles Philip Gabel; Antonio Cuesta-Vargas; Meihua Qian; Rok Vengust; Ulrich Berlemann; Emin Aghayev; Markus Melloh Journal: Eur Spine J Date: 2017-06-23 Impact factor: 3.134
Authors: Charles Philip Gabel; Antonio Cuesta-Vargas; Sebastian Barr; Stephanie Winkeljohn Black; Jason W Osborne; Markus Melloh Journal: Eur Spine J Date: 2016-04-04 Impact factor: 3.134
Authors: Charles P Gabel; Antonio I Cuesta-Vargas; Markus Melloh; Jason Osborne Journal: Health Qual Life Outcomes Date: 2014-03-10 Impact factor: 3.186
Authors: Carlijn H van Randeraad-van der Zee; Anna J H M Beurskens; Raymond A H M Swinkels; Jan J M Pool; Roy W Batterham; Richard H Osborne; Henrica C W de Vet Journal: Qual Life Res Date: 2015-10-14 Impact factor: 4.147
Authors: Wouter Schuller; Raymond W J G Ostelo; Richard Janssen; Henrica C W de Vet Journal: Health Qual Life Outcomes Date: 2014-04-15 Impact factor: 3.186
Authors: Hamid Reza Mokhtarinia; Azadeh Hosseini; Azam Maleki-Ghahfarokhi; Charles Philip Gabel; Majid Zohrabi Journal: Health Qual Life Outcomes Date: 2018-05-15 Impact factor: 3.186