Conceptual equivalence and health-related quality of life: an exploratory study in Japanese and Dutch cancer patients.

Medical Psychology, Leiden University Medical Center, P. O. Box 9555, 2300 RB, Leiden, The Netherlands.
Quality of Life Research (Impact Factor: 2.86). 08/2006; 15(6):1091-101. DOI: 10.1007/s11136-006-0049-1
Source: PubMed

ABSTRACT Research into the equivalence of Western and Japanese conceptualizations of health-related quality of life (HR-QOL) is scarce. We used the Western (European Organization for Research and Treatment of Cancer, EORTC-QLQ-C30) and the Japanese (HRQoL-20) questionnaire in order to analyze the conceptual similarity of HR-QOL factors, and the associations between specific symptom items with overall HR-QOL in Japanese (n=265) and Dutch (n=174) patients with various types of cancer. Both populations completed both instruments. In both patient groups, the overall health scale of the EORTC-QLQ-C30 correlated highly (r=0.59; p<0.001) with the HRQOL-20 composite average score, indicating substantial conceptual comparability. Relationships between all EORTC-QLQ-C30 symptom items with HR-QOL were examined by ranking their correlations with the two overall measures of HR-QOL. Comparable patterns in the Japanese and Dutch samples were observed. The results suggest a considerable conceptual equivalence of HR-QOL in Japanese and Dutch cancer patients, and indicate a satisfactory structural and cross-cultural equivalence for the EORTC-QLQ-C30 with regard to items measuring functioning and specific symptoms. Longitudinal studies are needed to examine the impact of specific symptoms on general quality of life.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Knowledge on cross-cultural quality of life (QOL) and illness perceptions may help women with breast cancer cope more effectively. The self regulation model (SRM) guided the current exploratory longitudinal pilot-study. Central to SRM is the perception of health threats and their effects on QOL. Illness perceptions and QOL were assessed in 22 Dutch and 21 Japanese patients with breast cancer who filled out questionnaires before, 1 week, and 8 weeks after the first chemotherapy course. The questionnaires assessed QOL and illness perceptions. Patients' scores were compared with groups of patients with other chronic somatic illnesses (asthma, diabetes). Patients in both samples reported major impact of chemotherapy on global health status, physical functioning, role functioning, emotional functioning, constipation and diarrhea. Differences between Japanese and Dutch patients were limited to social functioning and financial problems. Japanese patients expressed stronger concerns about their illness than Dutch patients. Results of the Japanese and Dutch patients with breast cancer differed from data in patients with asthma on consequences, timeline, concern and emotional response. Results of Japanese patients differed from patients with type 2 diabetes on timeline and concern, whereas Dutch patients differed on timeline and consequences. Japanese and Dutch breast cancer patients have-overall-similar illness perceptions and QOL responses and are aware of the typical characteristics of their disease. The results support the feasibility of cross-cultural psychosocial research in oncology and offer implications for clinical interventions which impact on self-efficacy to empower patients with breast cancer.
    Journal of Psychosocial Oncology 01/2013; 31(1):83-102. DOI:10.1080/07347332.2012.741092 · 1.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Quality of life studies in Indonesia are still uncommon. This research was aimed to validate the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 in Indonesian version. The standard procedure of forward-backward translation was adhered to in the translation procedures. The validity procedure included reliability, convergent and discriminant validity, known-groups validity, factor analysis and external convergent validity. Data were collected from cancer patients in the Oncology Department of Sardjito Hospital, Yogyakarta, Indonesia, who were treated with cisplatin at the dosage ≥50 mg/m(2) as monotherapy or in combinations. The Short Form-36 was used to assess the external convergent validity of our translated questionnaire. One hundred and twenty-eight patients were recruited from March 2009 to November 2009. The internal consistency with values of >0.70 was observed in the Indonesian version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 scales. All items in the questionnaire met the criteria of convergent and discriminant validity, except for items 5. Both of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 and the Short Form-36 showed that different diagnoses were associated with a similar impact on quality of life. Factor analysis showed that only the role function and social function loaded onto the second factor together. Correlations between the Indonesian versions of both questionnaires were moderate: between 0.18 and 0.48 for the physical, emotional, social, fatigue and pain domains. The Indonesian version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 can be used as a questionnaire to assess quality of life in Indonesian cancer patients with high-emetogenic treatments.
    Japanese Journal of Clinical Oncology 03/2011; 41(4):519-29. DOI:10.1093/jjco/hyq243 · 1.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Electron cryo-microscopy (cryo-EM) images are commonly collected using either charge-coupled devices (CCD) or photographic film. Both film and the current generation of 16 megapixel (4k × 4k) CCD cameras have yielded high-resolution structures. Yet, despite the many advantages of CCD cameras, more than two times as many structures of biological macromolecules have been published in recent years using photographic film. The continued preference to film, especially for subnanometer-resolution structures, may be partially influenced by the finer sampling and larger effective specimen imaging area offered by film. Large format digital cameras may finally allow them to overtake film as the preferred detector for cryo-EM. We have evaluated a 111-megapixel (10k × 10k) CCD camera with a 9 μm pixel size. The spectral signal-to-noise ratios of low dose images of carbon film indicate that this detector is capable of providing signal up to at least 2/5 Nyquist frequency potentially retrievable for 3D reconstructions of biological specimens, resulting in more than double the effective specimen imaging area of existing 4k × 4k CCD cameras. We verified our estimates using frozen-hydrated ε15 bacteriophage as a biological test specimen with previously determined structure, yielding a ∼7 Å resolution single particle reconstruction from only 80 CCD frames. Finally, we explored the limits of current CCD technology by comparing the performance of this detector to various CCD cameras used for recording data yielding subnanometer resolution cryo-EM structures submitted to the electron microscopy data bank (
    Journal of Structural Biology 05/2011; 175(3):384-93. DOI:10.1016/j.jsb.2011.05.012 · 3.37 Impact Factor

Full-text (2 Sources)

Available from
Sep 25, 2014