Validation of QLMS for Athlete With Spinal Cord Injuries

Background/Purpose: : The purposes of this study were to develop and calibrate the quality of life measurement scale (QLMS) for athlete with spinal cord injuries using the Rasch model, and to validate the scale through known group difference approach. If Activities of Daily Living (ADL) score is more than 15, independent living is generally possible (Korea Ministry of Health & Welfare, 2005)

Method: Based on the literature review and consultation of content and measurement experts, the 33-item OLMS was generated. The scale was administered to 158 athletes with spinal cord injuries in Korea National Sport University. Rasch measurement computer program, WINSTEPS(Linacre, 2009), was used to analyze the data. Model data fit was determined by Infit and Outfit statistics (≥0.70 and ≤1.30). The unidimensionality of the scale was determined by Infit and Outfit (mean square) using Chi-square fit statistics. If the values of the Infit and Outfit are 1.00, the observed score perfectly fit the expected model. One-way ANOVA was used to establish the known group difference validity evidence of the OLMS through SPSS 20.0 statistical software. Alpha level was set at 0.05. A statistically significant mean difference in the athlete’s quality of life between ADL score level(<15, ≥15) would provide known group difference validity evidence for the QLMS.

Analysis/Results: 23-item of the 33 items had good model-data fit with acceptable fit statistics. The 10 items were eliminated from the final estimation (5-item’s infit and outfit statistics index were over 1.30, and the other 5-itme’s infit and outfit statistics index were lower 0.70). Overall, a unidimensional model fits the data well and the 5 rating categories functioned well; threshold advanced with category. The item separation index (3.61) and separation reliability statistic (.93) provided evidence that the items had good variability with a high degree of confidence in replicating placement of the items from another sample. There was a statistically significant mean difference in the person's logits score between categorized the ADL group(<15, ≥15), F(1, 156) = 233.757, p < 0.001. This result supports the known group difference validity evidence of the OLMS.

Conclusions: Results provided support for using the OLMS. The scale can be used to assess the quality of life of individuals and provide health information to athlete with spinal cord injuries. The newly developed OLMS for athlete with spinal cord injuries in Korea should be validated to another sample to increase external validity.