Development and Validation of QOLS for University Athletes

Background/Purpose: The purpose of this study was to develop and validate the quality of life scale (QOLS) for the university athletes in Korea. Athletes in the university setting are unique and different from normal population, so a valid QOLS is needed to be developed. Convergent and discriminant validity evidence using confirmatory factor analysis (CFA) were examined to establish the validity evidence based on the internal structure of the QOLS.

Method: Based on the literature review and through consultation with content and measurement experts, a 25-item QOLS was generated. The scale consists of five factors: physical function (PF), economics (EC), social relationship (SR), self-esteem (SE), and emotional state (ES), and each factor has 5-items. The scale was administered to 221 university athletes in Korea. For convergent and discriminant validity, AMOS 21.0 program was used to analyze the data. Convergent validity was determined by composite reliability (CR) and average variance extracted (AVE). If CR is over 0.70 and AVE is over 0.50 for each factor, convergent validity is supported. Discriminant validity was determined by AVE and coefficient of determination (CD) that is a squared correlation between each two factors (i.e., PF-EC, PF-SR, PF-SE, PF-ES, EC-SR, EC-SE, EC-ES, SR-SE, SR-ES, and SE-ES). If each two factors’ AVE is bigger than the CD, discriminant validity is supported (Anderson & Gerbing, 1988).

Analysis/Results: 15 of the 25 items had good path coefficient (> .50) with acceptable fit statistics. The 10 items were eliminated from the final estimation, which resulted in 3-items for each factor. Overall, model fits the data well (non-normed fit index [NNFI] = .921; comparative fit index [CFI] = .940; root mean squared error of approximation [RMSEA] = .067). All factors (PF, EC, SR, SE, and ES) have acceptable CR (> .70) and AVE (> .50). All two factors’ CDs (i.e., PF-EC = .383, PF-SR = .265, PF-SE = .355, PF-ES = .004, EC-SR = .357, EC-SE = .373, EC-ES = .010, SR-SE = .363, SR-ES = .058, and SE-ES = .003) are lower than the AVEs, which demonstrated convergent and discriminant validity evidence.

Conclusions: This result supports validity evidence based on the internal structure of the QOLS. The scale can be used to assess the quality of life of individuals properly and provide meaningful information to university athletes. The newly developed QOLS for athletes in Korea should be validated with another sample to increase external validity.

Keywords: Convergent validity, Discriminant validity, Quality of Life Scale