Francisco Javier Cano-García1, Roger Muñoz-Navarro2, Albert Sesé Abad3, Luciana Sofía Moretti4, Leonardo Adrián Medrano4, Paloma Ruiz-Rodríguez5, César González-Blanch6, Juan A Moriana7, Antonio Cano-Vindel8. 1. Department of Personality, Assessment and Psychological Treatments, School of Psychology, Universidad de Sevilla, Spain. Electronic address: fjcano@us.es. 2. Department of Basic Psychology, School of Psychology, Universidad de Valencia, Spain. 3. Department of Psychology, School of Psychology, Universitat de les Illes Balears, Palma, Spain. 4. School of Psychology, Universidad Siglo 21, Córdoba, Argentina. 5. Castilla La Nueva Primary Care Centre, Health Service of Madrid, Fuenlabrada, Madrid, Spain. 6. Mental Health Centre, Marqués de Valdecilla University Hospital - IDIVAL, Santander, Cantabria, Spain. 7. Department of Psychology, Universidad de Córdoba/Maimónides Institute for Research in Biomedicine of Cordoba (IMIBIC)/Reina Sofía University Hospital, Córdoba, Spain. 8. Department of Experimental Psychology, School of Psychology, Universidad Complutense de Madrid, Madrid, Spain.
Abstract
BACKGROUND: Somatic symptoms are highly prevalent in primary care although insufficiently understood. The Patient Health Questionnaire (PHQ-15) is a valuable screening test but it has not yet been possible to unequivocally demonstrate its latent structure and measurement invariance. METHODS: A total of 1,255 patients from 28 primary care centres suffering symptoms of anxiety, depression or somatisation participated in a clinical trial. They completed the PHQ-15 at baseline and 374 retook it at three months. Exploratory structural equation modelling (ESEM) was used to compare three models: 1) a single global factor for somatisation, 2) four specific correlated factors, and 3) a bifactor model integrating the first two models. RESULTS: A multi-group invariance analysis of the best-fit model was performed: the bifactor model (χ2=25.17, df=23, p = 0.34, RMSEA=0.009, CFI=1.00, TLI=0.999). Strict invariance was good for both gender (RMSEA = 0.046, CFI = 0.973, TLI = 0.963) and age (RMSEA = 0.048, CFI = 0.964, TLI = 0.962). Configural and metric invariance were confirmed for moment of assessment, but scalar invariance was not. LIMITATIONS: The two main limitations were the sample (primary care patients with emotional disorders), which was not representative of the general population, and the utilisation of ESEM (vs. confirmatory factor analysis), which did not allow a second-order factor model to be tested. CONCLUSIONS: PHQ-15 showed a bifactor structure, providing both a single global measure of somatisation and specific measures of pain, gastrointestinal, cardiopulmonary and fatigue factors. Its factor invariance with regard to both gender and age was confirmed.
BACKGROUND: Somatic symptoms are highly prevalent in primary care although insufficiently understood. The Patient Health Questionnaire (PHQ-15) is a valuable screening test but it has not yet been possible to unequivocally demonstrate its latent structure and measurement invariance. METHODS: A total of 1,255 patients from 28 primary care centres suffering symptoms of anxiety, depression or somatisation participated in a clinical trial. They completed the PHQ-15 at baseline and 374 retook it at three months. Exploratory structural equation modelling (ESEM) was used to compare three models: 1) a single global factor for somatisation, 2) four specific correlated factors, and 3) a bifactor model integrating the first two models. RESULTS: A multi-group invariance analysis of the best-fit model was performed: the bifactor model (χ2=25.17, df=23, p = 0.34, RMSEA=0.009, CFI=1.00, TLI=0.999). Strict invariance was good for both gender (RMSEA = 0.046, CFI = 0.973, TLI = 0.963) and age (RMSEA = 0.048, CFI = 0.964, TLI = 0.962). Configural and metric invariance were confirmed for moment of assessment, but scalar invariance was not. LIMITATIONS: The two main limitations were the sample (primary care patients with emotional disorders), which was not representative of the general population, and the utilisation of ESEM (vs. confirmatory factor analysis), which did not allow a second-order factor model to be tested. CONCLUSIONS:PHQ-15 showed a bifactor structure, providing both a single global measure of somatisation and specific measures of pain, gastrointestinal, cardiopulmonary and fatigue factors. Its factor invariance with regard to both gender and age was confirmed.
Authors: David Watson; Holly F Levin-Aspenson; Monika A Waszczuk; Christopher C Conway; Tim Dalgleish; Michael N Dretsch; Nicholas R Eaton; Miriam K Forbes; Kelsie T Forbush; Kelsey A Hobbs; Giorgia Michelini; Brady D Nelson; Martin Sellbom; Tim Slade; Susan C South; Matthew Sunderland; Irwin Waldman; Michael Witthöft; Aidan G C Wright; Roman Kotov; Robert F Krueger Journal: World Psychiatry Date: 2022-02 Impact factor: 79.683
Authors: Marie Weinreich Petersen; Marianne Rosendal; Eva Ørnbøl; Per Fink; Torben Jørgensen; Thomas Meinertz Dantoft; Andreas Schröder Journal: BMJ Open Date: 2020-12-10 Impact factor: 2.692
Authors: Mark Shevlin; Emma Nolan; Marcin Owczarek; Orla McBride; Jamie Murphy; Jilly Gibson Miller; Todd K Hartman; Liat Levita; Liam Mason; Anton P Martinez; Ryan McKay; Thomas V A Stocks; Kate M Bennett; Philip Hyland; Richard P Bentall Journal: Br J Health Psychol Date: 2020-05-27