Cross-cultural adaptation, validity, and reliability of the Persian version of the spine functional index

Hamid Reza Mokhtarinia,Charles Philip Gabel,Azadeh Hosseini,Azam Maleki-Ghahfarokhi,Majid Zohrabi

doi:10.1186/s12955-018-0928-5

Abstract

BackgroundThere are various instruments and methods to evaluate spinal health and functional status. Whole-spine patient reported outcome (PRO) measures, such as the Spine Functional Index (SFI), assess the spine from the cervical to lumbo-sacral sections as a single kinetic chain. The aim of this study was to cross-culturally adapt the SFI for Persian speaking patients (SFI-Pr) and determine the psychometric properties of reliability and validity (convergent and construct) in a Persian patient population.MethodsThe SFI (English) PRO was translated into Persian according to published guidelines. Consecutive symptomatic spine patients (104 female and 120 male aged between 18 and 60) were recruited from three Iranian physiotherapy centers. Test-retest reliability was performed in a sub-sample (n = 31) at baseline and repeated between days 3–7. Convergent validity was determined by calculating the Pearson’s r correlation coefficient between the SFI-Pr and the Persian Roland Morris Questionnaire (RMQ) for back pain patients and the Neck Disability Index (NDI) for neck patients. Internal consistency was assessed using Cronbach’s α. Exploratory Factor Analysis (EFA) used Maximum Likelihood Extraction followed by Confirmatory Factor Analysis (CFA).ResultsHigh levels of internal consistency (α = 0.81, item range = 0.78–0.82) and test-retest reliability (r = 0.96, item range = 0.83–0.98) were obtained. Convergent validity was very good between the SFI and RMQ (r = 0.69) and good between the SFI and NDI (r = 0.57). The EFA from the perspective of parsimony suggests a one-factor solution that explained 26.5% of total variance. The CFA was inconclusive of the one factor structure as the sample size was inadequate. There were no floor or ceiling effects.ConclusionsThe SFI-Pr PRO can be applied as a specific whole-spine status assessment instrument for clinical and research studies in Persian language populations.

Highlights

There are various instruments and methods to evaluate spinal health and functional status
Exclusion criteria were refusal to participate in the study, low back pain (LBP) as a result of a specific spinal disease, infection, inflammatory conditions such as ankylosing spondylitis, tumor, fracture or the presence of cauda equina syndrome, age below 18 years, and poor Persian language comprehension
Translation process and cultural adaptation There was no major difficulty in completing the forward and backward translation which corresponded to the original version

Summary

Introduction

There are various instruments and methods to evaluate spinal health and functional status. There are various instruments and methods to evaluate spinal health, functional status and the effects of interventions and treatment Traditional procedures, such as physiological parameters of neural conduction velocity [12], range of motion, muscular strength, endurance [12, 13] and neurological tests [5, 6, 14] have been used. In many cases these physical parameters are unable to predict the performance of, and effects on ADL [13] Such traditional methods are Mokhtarinia et al Health and Quality of Life Outcomes (2018) 16:95 less representative of functional status [15]. A patient’s participation in their evaluation process using other instruments, such as patient reported outcome (PRO) measures, can lead to a clearer view of functional ability and the effectiveness of any interventions [15] and the individual overall status [9]

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