Assessing health-related quality of life is essential to evaluating patients' wellbeing before, during, and after cancer treatment; it is also important for researchers determining the efficacy and side effects of new therapies. Without a norm to which data can be compared, however, such assessments are of limited use. Researchers from Charité - Universitätsmedizin Berlin have remedied this situation for one commonly used quality of life measure, obtaining normative data from the general population in order to facilitate the interpretation of cancer patients' data on the QLQ-C30 health-related quality of life questionnaire of the European Organisation for Research and Treatment of Cancer (EORTC).
"The newly established norm values allow for a more precise interpretation of patient-reported quality of life data," commented the study's lead author, Sandra Nolte, PhD, of Charité's Health Outcomes Research Unit in the Division of Psychosomatic Medicine. "Norm values already existed for a number of countries. However, these were usually determined using different survey methodologies, meaning that they were not suitable for use in multinational studies. For the first time, we applied consistent data collection methods across all 15 included countries, facilitating valid intra- and especially inter-country comparisons and QLQ-C30 score interpretation."
For the study, published in the European Journal of Cancer, the researchers used an online survey to collect QLQ-C30 data from at least 1,000 individuals per country among the general population of 11 European Union countries, Russia, Turkey, Canada, and the United States. They generated a "European QLQ-C30 Norm" based on the EU countries, in addition to individual norm scores for all 15 countries included in the study. A total of 15,386 respondents completed the survey.
The investigators found that among data from the EU respondents, men generally scored somewhat higher on many health measures than women. Effects of age on health measures tended to vary according to the domain being measured. Inter-country comparisons showed much larger contrasts, with Austrian and Dutch participants indicating significantly better health than British and Polish participants.
Dr. Nolte emphasized the utility of the study's results: "This will be of benefit to researchers across the globe and, ultimately, to cancer patients."
For More Information
Nolte S, Liegl G, Petersen MA, et al (2019). General population normative data for the EORTC QLQ-C30 health-related quality of life questionnaire based on 15,386 persons across 13 European countries, Canada and the Unites States. Eur J Cancer, 107:153-163. DOI:10.1016/j.ejca.2018.11.024
Image courtesy of the National Cancer Institute