INTRODUCTION: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a widely used health-related quality of life instrument. The main aim of this study is to investigate whether there are international differences in response to the questionnaire that can be explained by cultural factors. METHODS: Analyses involved a database of 106 separate studies including data from over 28,000 respondents. Differential item functioning (DIF) analyses using logistic regression were conducted for each item of the EORTC QLQ-C30 with respect to cultural/geographic group. Results were qualitatively compared with previously reported DIF analyses by translation to explore whether the source of the DIF was more likely to be linguistic or cultural in nature. RESULTS: Although most response patterns were similar, there were a number of international differences in how the questionnaire was answered. The largest variations were found in the results for Eastern Europe and East Asia. Results for the UK, the US and Australia tended to be similar. Many of the European results followed patterns that were more clearly explained when grouped by translation than when grouped by geographical region. DISCUSSION: Our results suggest that, in general, the EORTC QLQ-C30 is suitable for use in a wide variety of countries and settings. Some response variations that have the potential to affect the results of international studies were identified, but it was not always clear whether the source of the variation was primarily linguistic or cultural.
INTRODUCTION: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a widely used health-related quality of life instrument. The main aim of this study is to investigate whether there are international differences in response to the questionnaire that can be explained by cultural factors. METHODS: Analyses involved a database of 106 separate studies including data from over 28,000 respondents. Differential item functioning (DIF) analyses using logistic regression were conducted for each item of the EORTC QLQ-C30 with respect to cultural/geographic group. Results were qualitatively compared with previously reported DIF analyses by translation to explore whether the source of the DIF was more likely to be linguistic or cultural in nature. RESULTS: Although most response patterns were similar, there were a number of international differences in how the questionnaire was answered. The largest variations were found in the results for Eastern Europe and East Asia. Results for the UK, the US and Australia tended to be similar. Many of the European results followed patterns that were more clearly explained when grouped by translation than when grouped by geographical region. DISCUSSION: Our results suggest that, in general, the EORTC QLQ-C30 is suitable for use in a wide variety of countries and settings. Some response variations that have the potential to affect the results of international studies were identified, but it was not always clear whether the source of the variation was primarily linguistic or cultural.
Authors: Morten Aa Petersen; Mogens Groenvold; Jakob B Bjorner; Neil Aaronson; Thierry Conroy; Ann Cull; Peter Fayers; Marianne Hjermstad; Mirjam Sprangers; Marianne Sullivan Journal: Qual Life Res Date: 2003-06 Impact factor: 4.147
Authors: N K Aaronson; S Ahmedzai; B Bergman; M Bullinger; A Cull; N J Duez; A Filiberti; H Flechtner; S B Fleishman; J C de Haes Journal: J Natl Cancer Inst Date: 1993-03-03 Impact factor: 13.506
Authors: Neil W Scott; Peter M Fayers; Neil K Aaronson; Andrew Bottomley; Alexander de Graeff; Mogens Groenvold; Chad Gundy; Michael Koller; Morten A Petersen; Mirjam A G Sprangers Journal: Qual Life Res Date: 2009-08-04 Impact factor: 4.147
Authors: Vincent Chung; Marc Chong; Lau Chun Hong; Polly H X Ma; Samuel Y S Wong; Sian M Griffiths Journal: Chin J Integr Med Date: 2012-07-22 Impact factor: 1.978
Authors: Neil W Scott; Josephine A Etta; Neil K Aaronson; Andrew Bottomley; Peter M Fayers; Mogens Groenvold; Michael Koller; Dagmara Kuliś; Debbi Marais; Morten A Petersen; Mirjam A G Sprangers Journal: Qual Life Res Date: 2012-10-02 Impact factor: 4.147
Authors: Neil W Scott; Peter M Fayers; Neil K Aaronson; Andrew Bottomley; Alexander de Graeff; Mogens Groenvold; Chad Gundy; Michael Koller; Morten A Petersen; Mirjam A G Sprangers Journal: Health Qual Life Outcomes Date: 2010-08-04 Impact factor: 3.186