biostudies-literatureTso WWYThe University of Hong Kong Outstanding Young Researcher AwardHong Kong Research Grants Council General Research Fund (GRF)Seed Fund for Basic Research (HKU University Research Committee)Hong Kong Research Grants Council Collaborative Research FundState Key Laboratory of Brain and Cognitive Sciences, University of Hong KongHong Kong Research Grants Council General Research FundSeed Fund for Basic Researchthe University of Hong Kong Research Output PrizeThe Society for the Relief of Disabled Children81https://www.ebi.ac.uk/biostudies/studies/S-EPMC11645425biostudies-literatureUnknown184(1)This study aims to develop and validate the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y), which is a comprehensive tool for measuring the symptom burden of post-COVID-19 conditions-persistent symptoms after SARS-CoV-2 infection, commonly known as Long COVID-and its impact on health-related quality of life among children and adolescents. Parents of children and adolescents, adolescents, and young adults with and without a history of COVID-19 were invited to fill in a questionnaire from October 2022 to June 2023. There were 386 valid parent proxy-reported responses, 433 valid adolescent self-reported responses, and 324 valid young adult self-reported responses included in the final analysis. The PCSS-C/Y demonstrated stable factor structure and good internal consistency in differenEuropean journal of pediatricsDevelopment and validation of the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y).PMC11645425202111159117,C7149-20C7060-21G17600924Duque JSRLee TMCKwan MYWChau CSKHui KYLau YLChan JYKIp PFong DYTChan JFWTsao SSLYip KMLeung LKWang YTso WWYfalseDevelopment and validation of the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y).This study aims to develop and validate the Post-COVID Symptom Scale for Children/Youth (PCSS-C/Y), which is a comprehensive tool for measuring the symptom burden of post-COVID-19 conditions-persistent symptoms after SARS-CoV-2 infection, commonly known as Long COVID-and its impact on health-related quality of life among children and adolescents. Parents of children and adolescents, adolescents, and young adults with and without a history of COVID-19 were invited to fill in a questionnaire from October 2022 to June 2023. There were 386 valid parent proxy-reported responses, 433 valid adolescent self-reported responses, and 324 valid young adult self-reported responses included in the final analysis. The PCSS-C/Y demonstrated stable factor structure and good internal consistency in differen2024-01-01T00:00:00Z2024 Dec2025-04-04T02:43:45.4Z2025-04-04T02:43:45.4ZS-EPMC116454253967300510.1007/s00431-024-05913-9