Psychometric evaluation of the Chinese version of the revised illness perception questionnaire for breast cancer-related lymphedema

Abstract

The aim of this study was to modify and test the Chinese version of the Revised Illness Perception Questionnaire to measure the illness perception of breast cancer-related lymphedema among breast cancer survivors. Before the investigation, identity and causal subscales were modified and the wording of the remaining scales was also adjusted. The psychometric properties of this instrument was evaluated using the technique of explore and confirmatory factor analysis. Data from 203 breast cancer survivors was entered into factor analysis. Five causal factors were extracted after removing one item, accounting for 68.02% of the variance in total. An acceptable fit with the data for the proposed seven-factor model was obtained after eliminating three items and resetting seven error covariances. The Cronbach's α values and composite reliability coefficients were acceptable. This measurement is reliable and valid for measuring illness perceptions of breast cancer-related lymphedema in Chinese breast cancer survivors. It could be helpful for further studies that examine the effect of illness perceptions on health-related behaviours, such as lymphedema risk-reduction behaviours in the Chinese cultural context.

Keywords: breast cancer; factor analysis; illness perception; instrument; lymphedema; psychometric evaluation.