Examining the psychometric properties of the sport psychology professional quality of life scale using item response theory

Recognizing the importance of the quality of the professional life for sport psychology professionals (SPPs), scholars have developed an initial conceptualization of Sport Psychology-Professional Quality of Life (SP-PQL), which encompass three main factors: the multifaceted nature of SP-PQL, the challenges hindering SP-PQL, and the strategies fostering SP-PQL. To assess this construct, Quartiroli and colleagues (2019) developed via a Delphi study a 42-item multi-dimensional measure. With the present study, we offer an initial examination of the psychometric characteristics of the SP-PQL measure. Cross-sectional survey data were gathered via an online survey from 614 sport psychology professionals (n = 527) and trainees (n = 79). The dataset was analyzed using a novel Item Response Theory approach. Specifically, using a multidimensional graded response model, we evaluated the overall performance of the three-factor SP-PQL measure and the item-response combinations. Our results showed inadequate model fit when evaluated using the M2 statistic and RMSEA, and we identified several poor functioning items as providing low discrimination or low information (n = 9), showing unintended loading (n = 1), or having poor threshold/response option utility (n = 2). After removing these items, the model was re-run to evaluate the impact of the alterations on model fit and total test information provided by the original and modified versions. The analysis suggested very little to no loss of information from the removal of items, and model fit statistics for the modified measure improved, albeit fit remained inadequate. Based on these results, we argue that further refinement of the SP-PQL measure is necessary for psychometric use in research, but that the measure may hold some utility for SPPs wanting to reflect on their PQL. Our analyses also demonstrate the value of using IRT approaches to evaluate the performance of individual items within psychometric measures.