DEVELOPING THE KOREAN LEEDS SATISFACTION QUESTIONNAIRE (KOREAN-LSQ) IN RHEUMATOID ARTHRITIS: A CROSS-CULTURAL VALIDATION USING RASCH ANALYSIS

Abstract

Background The Leeds Satisfaction Questionnaire (LSQ)1 is a patient-completed questionnaire designed to measure satisfaction among patients attending a rheumatology outpatient clinic. It was originally developed in the UK and it comprises 45 items grouped into 6 subscales: general satisfaction, information, empathy, technical competence, attitude, access and continuity.

Objectives To undertake cross-cultural adaptation and validation of the LSQ in RA for use in Korea.

Methods The adaptation of the LSQ from English into Korean was established according to guideline of cross-cultural adaptation of self-report measures.2 Patients with RA were then recruited from an outpatient clinic of a university hospital in South Korea and Cross-cultural validation of the Korean-LSQ was carried out by Rasch analysis using the WINSTEPS program. Model data fit was determined by Infit and Outfit statistics (≥0.50 and ≤1.50). If the values of the Infit and Outfit are 1.00, the observed score perfectly fit the expected model. The unidimensionality of the scale was determined by separation index (SI ≥2.00) and reliability (RI ≥0.80).

Results An adequate conceptual equivalence was achieved following the adaptation process. The dataset for validation comprised 125 patients, 103 (82.4%) of whom were female, mean (SD) age =47.2 (12.5) and disease duration =52.8 (69.4) months. Forty-item of the 45 items had acceptable fit statistics (individual item data not shown). The individual items overall had good separation index and reliability (SI =5.98 and RI =0.97). Analysis of the 6 subscales of the Korean-LSQ resulted in good fit to the Rasch model (Table 1), high internal consistency and unidimensionality (Person SI =2.31 and RI =0.84; item SI =5.44 and RI =0.97).

Conclusions Fit to the Rasch model confirmed that the construct validity, reliability, and unidimensionality of the Korean-LSQ were preserved after the adaptation process. The Korean LSQ is a valid and reliable tool for measuring satisfaction with care among patients with RA in South Korea.