Validity and Reliability of Bengali Language Shoulder Pain and Disability Index Version on Patients With Frozen Shoulder at a Rehabilitation Centre in Bangladesh: A Validation Study

Abstract

Background and Aims

The shoulder pain and disability index (SPADI) is a commonly utilized outcome measure. The study aimed to evaluate the reliability and validity of the Bengali version of the SPADI among patients with frozen shoulder.

Methods

The SPADI was administered to 103 patients with frozen shoulder receiving physiotherapy at Centre for the rehabilitation of the paralyzed (CRP), a well-known rehabilitation hospital in Bangladesh. Among these patients, 31 underwent a retest after 15 days. To evaluate the construct validity of the SPADI, the scores were compared with other outcome measures, including the disabilities of the arm, shoulder, and hand questionnaire (DASH), the numerical pain rating scale (NPRS), and the 36-item short form health survey (SF-36). Structural validity was assessed using a two-factor confirmatory factor analysis (CFA). Additionally, the study analyzed internal consistency, test–retest reliability, and measurement error.

Results

This study validated the Bengali version of the SPADI for frozen shoulder (FS). It showed strong psychometric properties, including high internal consistency (pain α = 0.842, disability α = 0.878), and reliability (ICC > 0.98). A confirmatory factor analysis confirmed a two-factor structure (CFI = 0.985). Findings highlight SPADI's value in FS assessment while emphasizing its limitations in capturing broader quality-of-life impacts.

Conclusion

The Bengali version of SPADI showed good reliability and validity in a group of patients with frozen shoulder. This means that it is a dependable and accurate tool for measuring shoulder pain and disability in these patients.