ORIGINAL ARTICLE International field testing of the psychometric properties of an EORTC quality of life module for oral health: the EORTC QLQ-OH15 Marianne J. Hjermstad 1,2 & Mia Bergenmar 3,4 & Kristin Bjordal 5 & Sheila E. Fisher 6 & Dirk Hofmeister 7 & Sébastien Montel 8 & Ourania Nicolatou-Galitis 9 & Monica Pinto 10 & Judith Raber-Durlacher 11 & Susanne Singer 12 & Iwona M. Tomaszewska 13 & Krzysztof A. Tomaszewski 14 & Irma Verdonck-de Leeuw 15 & Noam Yarom 16,17 & Julie B Winstanley 18,19 & Bente B. Herlofson 20 & on behalf of the EORTC QoL Group Received: 12 January 2016 /Accepted: 5 April 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Purpose This international EORTC validation study (phase IV) is aimed at testing the psychometric properties of a quality of life (QoL) module related to oral health problems in cancer patients. Methods The phase III module comprised 17 items with four hypothesized multi-item scales and three single items. In phase IV, patients with mixed cancers, in different treatment phases from 10 countries completed the EORTC QLQ-C30, the QLQ-OH module, and a debriefing interview. The hypoth- esized structure was tested using combinations of classical test theory and item response theory, following EORTC guide- lines. Test–retest assessments and responsiveness to change analysis (RCA) were performed after 2 weeks. Results Five hundred seventy-two patients (median age 60.3, 54 % females) were analyzed. Completion took <10 min for 84 %, 40 % expressed satisfaction that these issues were ad- dressed. Analyses suggested a revision of the phase III hy- pothesized scale structure. Two items were deleted based on a high degree of item misfit, together with negative patient * Marianne J. Hjermstad marianne.j.hjermstad@ntnu.no 1 Regional Centre for Excellence in Palliative Care, Department of Oncology, Oslo University Hospital, Oslo, Norway 2 European Palliative Care Research Centre, Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University for Science and Technology, Trondheim, Norway 3 Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden 4 Department of Oncology, Karolinska University Hospital, Stockholm, Sweden 5 Oslo University Hospital, Oslo, Norway 6 University of Leeds, Leeds LS2 9JT, UK 7 University of Leipzig, Leipzig, Germany 8 Department of Psychology, University Paris Saint Denis, Paris, France 9 University of Athens, Athens, Greece 10 Rehabilitation Unit, Department of Quality of Life, Istituto Nazionale Tumori BFondazione G. Pascale^—IRCCS, Naples, Italy 11 Department of Oral and Maxillofacial Surgery, Academic Medical Center University of Amsterdam, Amsterdam, Netherlands 12 Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Centre, Mainz, Germany 13 Department of Medical Education, Jagiellonian University Medical College, Krakow, Poland 14 Department of Anatomy, Jagiellonian University Medical College, Krakow, Poland 15 Department of Otolaryngology—Head and Neck Surgery, VU University Medical Center, Amsterdam, Netherlands 16 Department of Oral and Maxillofacial Surgery, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel 17 Department of Oral Pathology and Oral Medicine, School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel 18 Patricia Ritchie Centre, University of Sydney, Sydney, Australia 19 Osman Consulting Pty LTD, Sydney, Australia 20 Department of Oral Surgery and Oral Medicine, Faculty of Dentistry, University of Oslo, Oslo, Norway Support Care Cancer DOI 10.1007/s00520-016-3216-0