Reassessment of the Psychometric Characteristics and Factor Structure of the ‘Perceived Stress Questionnaire’ (PSQ): Analysis in a Sample of Dental Students

Jesús Montero-Marin,Marina Olea,Marcelo Marcos Piva Demarzo,Javier García-Campayo,Joao Paulo Pereira,Marianna Mazza

doi:10.1371/journal.pone.0087071

Abstract

BackgroundThe training to become a dentist can create psychological distress. The present study evaluates the structure of the ‘Perceived Stress Questionnaire’ (PSQ), its internal consistency model and interrelatedness with burnout, anxiety, depression and resilience among dental students.MethodsThe study employed a cross-sectional design. A sample of Spanish dental students (n = 314) completed the PSQ, the ‘Goldberg Anxiety and Depression Scale’ (GADS), ‘Connor-Davidson Resilience Scale’ (10-item CD-RISC) and ‘Maslach Burnout Inventory-Student Survey’ (MBI-SS). The structure was estimated using Parallel Analysis from polychoric correlations. Unweighted Least Squares was the method for factor extraction, using the Item Response Theory to evaluate the discriminative power of items. Internal consistency was assessed by squaring the correlation between the latent true variable and the observed variable. The relationships between the PSQ and the other constructs were analysed using Spearman’s coefficient.ResultsThe results showed a PSQ structure through two sub-factors (‘frustration’ and ‘tenseness’) with regard to one general factor (‘perceived stress’). Items that did not satisfy discriminative capacity were rejected. The model fit were acceptable (GFI = 0.98; RSMR = 0.06; AGFI = 0.98; NFI = 0.98; RFI = 0.98). All the factors showed adequate internal consistency as measured by the congeneric model (≥0.91). High and significant associations were observed between perceived stress and burnout, anxiety, depression and resilience.ConclusionsThe PSQ showed a hierarchical bi-factor structure among Spanish dental students. Using the questionnaire as a uni-dimensional scale may be useful in perceived stress level discrimination, while the sub-factors could help us to refine perceived stress analysis and improve therapeutic processes.

Highlights

The training to become a health professional can create psychological distress and symptoms of burnout, which may have adverse consequences for one’s personal and professional life [1,2,3,4,5]
We examined the fit of the proposed Perceived Stress Questionnaire’ (PSQ) model by CFA, applying Unweighted Least Squares (ULS) from a polychoric matrix, for the reasons stated above
In order to adhere to standards for data availability, the authors state that all materials used to produce the results in this paper will be made available upon request

Summary

Introduction

The training to become a health professional can create psychological distress and symptoms of burnout, which may have adverse consequences for one’s personal and professional life [1,2,3,4,5]. ‘Stress’ occurs when environmental demands overwhelm individuals’ resources and threaten their personal well-being It has been defined as the result of a relationship with the environment that individuals appraise as significant for their well-being and in which the demands exceed the available coping resources [11]. ‘Burnout’ is a response to the failure to cope adequately with chronic occupational stress and is an attempt to adapt to or to protect oneself from it [12]. This syndrome has classically been characterized by a state of exhaustion, cynicism and inefficacy [13]. The present study evaluates the structure of the ‘Perceived Stress Questionnaire’ (PSQ), its internal consistency model and interrelatedness with burnout, anxiety, depression and resilience among dental students

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Discussion

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