Unique and combined effects of competence, autonomy and relatedness on quality of life and physical activity among adolescents


Psychological needs satisfaction (PNS) fosters adaptive psychological and behavioural outcomes. However, research to date has been limited by either disentangling specific PNS factors (competence, autonomy, relatedness) or by regrouping them into a global PNS factor. Using bi-factor analysis, a form of factor analysis, enables specific and global PNS factors to be examined simultaneously to understand how they uniquely relate to key outcomes. We examined if (1) PNS in physical activity (PA) contexts could be operationalized to represent specific needs of competence, autonomy, and relatedness as well as a global PNS factor, and (2) global PNS was associated with quality of life (QOL) and PA beyond the specific PNS factors. Data from 564 adolescents (Mage=13.62, SD=.63) who completed questionnaires in the Fall of 2014 for the MATCH study were analyzed. A bi-factor model specifying one global and three specific PNS factors provided a good fit to the data [?2(75)=289.83, CFI=.95, TLI=.93, RMSEA=.07 (90%CI=0.06,0.08)]. Results of the model including QOL (R2=.12) and PA (R2=.31) as outcomes of PNS also provided a good fit to the data [?2(97)=343.52, CFI=.95, TLI=.93, RMSEA=.07 (90%CI=0.06,0.07]. Global PNS was independently associated with QOL (ß=.31), whereas competence (ß=.28), relatedness (ß=.12) and global PNS (ß=.47) were independently associated with PA (p's<.05). By simultaneously estimating their relationships, this study demonstrates that specific and global PNS have unique and empirically distinguishable relationships with QOL and PA. Researchers can use bi-factor analysis to overcome methodological limitations encountered when studying the unique and combined associations between PNS and relevant outcomes.

Acknowledgments: The MATCH study is supported by the New Brunswick Health Research Foundation (#20130729) and by the Social Sciences and Humanities Research Council and Sport Canada through the joint Sport Participation Research Initiative (#862-2010-0001).