Health-related quality of life in young adult patients with rheumatoid arthritis in Iran: reliability and validity of the Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version

The objective of the present study was to determine the reliability and validity of the Persian translation of the Pediatric Quality of Life Inventory (PedsQLTM) 4.0 Generic Core Scales Young Adult Version in an Iranian sample of young adult patients with rheumatoid arthritis (RA). One hundred ninety-seven young adult patients with RA completed the 23-item PedsQLTM and the 36-item ShortForm Health Survey (SF-36). Disease activity based on Disease Activity Score 28 was also measured. Internal consistency and test-retest reliability, as well as construct, discriminant, and convergent validity, were tested. Confirmatory factor analysis (CFA) was used to verify the original factor structure of the PedsQLTM. Also, responsiveness to change in PedsQLTM scores over time was assessed. Cronbach’s alpha coefficients ranged from � = 0.82 to � = 0.91. Test-retest reproducibility was satisfactory for all scales and the total scale score. The PedsQL proved good convergent validity with the SF-36. The PedsQL distinguished well between young adult patients and healthy young adults and also RA groups with different comorbidities. The CFA did not confirm the original four-factor model, instead, analyses revealed a best-fitting five-factor model for the PedsQLTM Young Adult Version. Repeated measures analysis of variance indicated that the PedsQL scale scores for young adults increased significantly over time. The Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version demonstrated good psychometric properties in young adult patients with RA and can be recommended for the use in RA research in Iran. DOI: https://doi.org/10.1007/s10067-012-2084-3 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-67041 Accepted Version Originally published at: Pakpour, Amir H; Zeidi, Isa Mohammadi; Hashemi, Fariba; Saffari, Mohsen; Burri, Andrea (2013). Health-related quality of life in young adult patients with rheumatoid arthritis in Iran: reliability and validity of the Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version. Clinical rheumatology, 32(1):15-22. DOI: https://doi.org/10.1007/s10067-012-2084-3 Health-Related Quality of life in Young Adult Patients with Rheumatoid Arthritis in Iran: Reliability and Validity of the Persian Translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version Amir H Pakpour * 1, , Isa Mohammadi Zeidi, Fariba Hashemi , Mohsen Saffari Andrea Burri 1 Qazvin Research Center for Social Determinants of Health, Qazvin University of Medical Sciences, Qazvin, Iran 2 Department of Public Health, Qazvin University of Medical Sciences, Qazvin, Iran 3 Department of Health Education, Baqiyatallah University of Medical Sciences, Tehran, Iran 4 Department of Twin Research and Genetic Epidemiology, King's College London 5 University of Zurich, Department of Psychology, Psychopathology and Clinical Intervention, Switzerland. Running Head: rheumatoid arthritis and quality of life in young adults Address correspondence to: Amir H Pakpour, PhD, Assistant professor, Department of Public Health, Qazvin University of Medical Sciences, Qazvin, Iran. Phone: +98-281-3338127 Fax: +98-281-3345862 Email: [email protected] Abstract The objective of the present study was to determine the reliability and validity of the Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version in an Iranian sample of young adult patients with rheumatoid arthritis (RA). 197 young adult patients with RA completed the 23-item PedsQLTM and the 36-item SF-36 Health Survey. Disease activity based on Disease Activity Score 28 (DAS28) was also measured. Internal consistency and test–retest reliability, as well as construct, discriminant and convergent validity were tested. Confirmatory factor analysis (CFA) was used to verify the original factor structure of the PedsQLTM. Also, responsiveness to change in PedsQLTM scores over time was assessed. Cronbach’s alpha coefficientsThe objective of the present study was to determine the reliability and validity of the Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version in an Iranian sample of young adult patients with rheumatoid arthritis (RA). 197 young adult patients with RA completed the 23-item PedsQLTM and the 36-item SF-36 Health Survey. Disease activity based on Disease Activity Score 28 (DAS28) was also measured. Internal consistency and test–retest reliability, as well as construct, discriminant and convergent validity were tested. Confirmatory factor analysis (CFA) was used to verify the original factor structure of the PedsQLTM. Also, responsiveness to change in PedsQLTM scores over time was assessed. Cronbach’s alpha coefficients ranged from α=0.82 to α=0.91. Test-retest reproducibility was satisfactory for all scales and the total scale score. The PedsQL proved good convergent validity with the SF-36. The PedsQL distinguished well between young adult patients and healthy young adults and also RA groups with different comorbidities. The CFA did not confirm the original four-factor model, instead analyses revealed a best-fitting fivefactor model for the PedsQLTM Young Adult Version. Repeated-measures analysis of variance indicated that the PedsQL scale scores for young adults increased significantly over time. The Persian translation of the PedsQLTM 4.0 Generic Core Scales Young Adult Version demonstrated good psychometric properties in young adult patients with RA and can be recommended for the use in RA research in Iran.