Reliability, validity and responsiveness of the Mandarin (Simplified) Chinese version of the EORTC QLQ-OH45 among cancer patients.

Purpose: The goal of our study was to evaluate the reliability, validity, responsiveness and acceptability of the Mandarin (simplified) Chinese version of the EORTC QLQ-OH45.

Methods: From October 2017 to February 2018, 393 cancer patients were enrolled from three different hospitals in China. A forward and backward translation was made to develop the Mandarin (simplified) Chinese version of EORTC QLQ-OH15. The QLQ-C30 and QLQ-OH15 questionnaires (which we have assembled and named QLQ-OH45 in this paper) were self-administered. Results were statistically analysed using SPSS 21.0. The reliability and validity tests of the questionnaires were assessed by Cronbach's α coefficient, Pearson correlation test and Mann-Whitney U tests. Responsiveness to change was measured in an independent sample of patients with head and neck cancer undergoing surgery or radiotherapy or chemotherapy.

Results: An acceptable internal consistency reliability for most multiple-item scales was demonstrated, as Cronbach's α coefficients were greater than 0.7 for most multiple-item scales, excepting for cognitive functioning (0.36) and oral health-related QoL functioning (0.55). All domain's test-retest reliability coefficients (r) was higher than 0.8. Multi-trait scaling analysis showed good convergent and discriminant validity. A difference in the quality of life (QoL) between older (≥65 years) and younger (<65 years) groups of patients was showed by the known-group comparisons. Low correlations were found between the scales of the QLQ-OH15 and QLQ-C30 in all areas.

Conclusion: The Mandarin (simplified) Chinese version of QLQ-OH45 demonstrates satisfactory psychometric properties and can be used to measure the oral health-related QoL (OHRQoL) for Chinese cancer patients.