Exploring methods for health-related quality-of-life instrument translation and validation: A first look at the Norwegian EORTC-QLQ-LMC21

Abstract

BACKGROUND: Colorectal cancer is the second most common cancer in Norway, with the incidence rate increasing for both men and women. Patients with colorectal cancer commonly experience metastases in the liver. In Norway, about 30% of patients will have liver metastases at the time of diagnosis, and another 20% will develop metastases during the course of their treatment. Because interventions aimed at curing or managing this disease may have a negative impact on patient health, measuring patient outcomes in the form of health-related quality-of-life is important to assess the relative benefits of these interventions to patients. Disease specific health-related quality-of-life measures have been found to be more sensitive to the health states of patients, however the disease specific measure used for assessing health-related quality-of-life in colorectal cancer patients with liver metastases has previously not been available in the Norwegian language. OBJECTIVE: This cross-sectional study seeks to explore the methods used in the translation and psychometric assessment of health-related quality-of-life instruments and preliminarily assess the quality of the Norwegian EORTC-QLQ-LMC21 in terms of validity, reliability, responsiveness and equivalence with the English version. METHOD: This study is divided into two parts: (1) the qualitative translation process; and (2) the qualitative psychometric assessment of the resulting translated instrument. The EORTC-QLQ-LMC21 was first translated from English into Norwegian according to the recommendations of the instrument's governing body. The process was documented and the quality of the translation qualitatively assessed through translator feedback, content validity exploration, and patient feedback and acceptance. The validity, reliability, responsiveness, and equivalence of the translated questionnaire were then quantitatively assessed using Pearson's Product Movement of Correlation, Cronbach's alpha, and floor and ceiling effects. RESULTS: The EORTC-QLQ-LMC21 had good patient acceptance and performed fair to good on tests of validity, reliability, responsiveness and equivalence. The psychometric performance of the abdominal pain scale was poor due to one particular item, but there is nonetheless preliminary evidence for an acceptable level of quality and ability to meaningfully measure the health-related quality-of-life of this patient group.