Validity and Reliability of an Arabic Version of the Survey Instrument for Natural History, Aetiology and Prevalence of Patellofemoral Pain Studies: A Cross-Sectional Study

Abstract

Background and Objectives: Knee pain, specifically patellofemoral pain (PFP), may lead to limitations in physical activity and social participation. Identifying knee pain that is attributed to PFP is not an easy job for healthcare professionals. To overcome this issue, The Survey Instrument for Natural History, Aetiology and Prevalence of Patellofemoral Pain (SNAPPS), which is a self-reporting questionnaire instrument, was designed to identify PFP in many languages. However, the Arabic version of the SNAPPS is not validated yet. This study was performed to assess the validity and reliability of the Arabic version of the SNAPPS (A-SNAPPS). Materials and Methods: A cross-sectional study was conducted to achieve the study goals. To assess reliability, 38 participants were asked to complete the A-SNAPPS two times on the same day with a 30 min break in between. Convergent validity of the A-SNAPPS was assessed by exploring the correlations of the SNAPPS total score with the visual analogue scale (VAS) scores, including VAS for usual pain, VAS for worst pain, and VAS for pain during activities such as jumping, running, ascending and descending stairs, and squatting. Results: The validity test findings suggested that SNAPPS has a strong correlation with the VAS during ascending and descending stairs (r = 0.71) and moderate correlations during jumping (r = 0.54) and squatting (r = 0.57). The test–retest reliability ICC was 0.92, indicating a very strong test–retest reliability of the A-SNAPPS. Conclusions: The A-SNAPPS was cross-culturally adapted and validated, demonstrating very strong reliability.