The Reliability and Validity of Liu´s Self-Report Questionnaire for Screening Putative Pre-Psychotic States (BQSPS) in Adolescents

Abstract

The usage of rigorous analyses based on contemporary methods to enhance psychometric properties of screening questionnaires aimed to address psychotic-like experiences (PLE) is currently being encouraged. The Brief Self-Report Questionnaire for Screening Putative Pre-psychotic States (BQSPS) is a recently created tool addressing PLE beyond attenuated positive symptoms (APS). Its psychometric properties as a screening tool for first step assessment seems to be adequate, but further research is needed to evaluate certain validity aspects, particularly its dimensionality, internal structure, and psychometric properties in different populations. We assessed the reliability, construct validity, and criterion validity of BQSPS in two samples: 727 adolescents aged 13–18 years, and 245 young adults aged 18–33 years. We used exploratory structural equation modeling (ESEM), confirmatory factor analysis (CFA), and Structural Equation Modeling (SEM). The original four-factor structure was not replicated. The best fit in adolescents was obtained by a structure of three-correlated factors: social anxiety (SA), negative symptoms (NS), and positive symptoms (PS). This structure was confirmed in young adult subjects. The three-factor model reached a predictive capability with suicidality as external criterion. PLE are represented by a three-factor structure, which is highly stable between adolescent and young-adult samples. Although the BQSPS seems to be a valid tool for screening PLE, its psychometric properties should be improved to obtain a more accurate measurement.

Psychometric properties of the brief self-report questionnaire for screening putative pre-psychotic states and validation of clinical utility in young adult

“…Finally, component 1 has six items, component 2 has five items, and component 3 has four items. The first component is composed of six items from the Social Anxiety Scale of Nüñez et al [ 8 ]. The item loadings range from.48 to.72, while the component explains 24.98% of the total variance.…”

“…These strategies focus on the early detection of subjects who show only subthreshold symptoms, including positive and negative symptoms or functional difficulties appearing in the prodrome phase of psychosis [ 7 ]. Measures for the early detection of people at risk of psychosis have been created and tested during the last two decades [ 8 ]. As part of this strategy, the Brief Self-Report Questionnaire for Screening Putative Pre-Psychotic States (BQSPS) was developed [ 9 ], with confirmed reliability and validity [ 8 , 10 ].…”

“…Measures for the early detection of people at risk of psychosis have been created and tested during the last two decades [ 8 ]. As part of this strategy, the Brief Self-Report Questionnaire for Screening Putative Pre-Psychotic States (BQSPS) was developed [ 9 ], with confirmed reliability and validity [ 8 , 10 ].…”

“…Demmin et al found moderate to large convergent validity, acceptable internal consistency for each scale, and modest test-retest reliability, recommending its usage for screening psychotic-like experience in college populations [ 10 ]. Similarly, Nunez et al found a stable structure of three correlated factors: social anxiety (SA), negative symptoms (NS), and positive symptoms (PS) in adolescent and young adult subjects [ 8 ]. This three-factor model also had the predictive ability for suicidality as an external criterion.…”

“…Since there is a recognized need for developing shorter questionnaires with robust psychometric properties [ 12 , 25 ] the current study uses exploratory factor analyses to examine the internal structure of the BQSPS and compares the results with Nunez et al [ 8 ]. We then test associations between the BQSPS and related criteria to determine their contributions to the explained variance of the BQSPS.…”