Test-retest reliability and convergent validity of the Ruffier Index in children under 12 years old

• Published in: Science & sports 2018-12, Vol.33 (6), p.353-360
• Main Authors: Ayán Pérez, C., Reigosa Galáns, F., Cancela Carral, J.M., Rodríguez Barreiro, H., Martínez-Lemos, I.
• Format: Article
• Language: English
• Subjects: Children & youth; Oxygen; Reliability; Test methods; Validity
• ISSN: 0765-1597
• DOI: 10.1016/j.scispo.2018.05.002

Objective. - This study aimed at identifying the test-retest reliability and convergent validity of the Ruffier Index (Rl) when performed by children. Methods.- A total of 3526/11/2018participants (mean age: 10.41 ±1.02 years; 47.2% girls) carried out the Ruffier test twice with an interval of one week between both evaluations, to identify the Rl test-retest reliability. The maximal oxygen consumption as estimated by the Course-Navette test was used to determine its convergent validity. Results. - The Rl showed a "poor" test-retest reliability (ICC = 0.43-0.64). The relationship between Rl and estimated maximal oxygen consumption was "acceptable" for both the test (r= -0.37; P = 0.003) and retest (r- -0.32; P-0.01) in the girls' case, while for the boys it was "poor" (r--0.12;P-0.04 and r--0.25; P-0.02). Conclusion. - The findings of this study indicate that the Rl shows a "poor" test-retest reliability and a convergent validity ranging from "acceptable" to "poor", when administered to children under 12 years of age.