title: Development and validation of quality of life scale of nasopharyngeal carcinoma patients: the QOL-NPC (version 2).
abstract: BACKGROUND
  The aim was to develop and validate the quality of life scale for nasopharyngeal carcinoma (NPC) patients, the QOL-NPC (version 2), a specific instrument to measure quality of life for NPC patients.
  
  
  METHODS
  The QOL-NPC was developed and validated according to standard procedures. The patients were assessed using the QOL-NPC, FACT-G, and FACT-H&N. Classical test theory was used to evaluate the reliability, validity, and responsiveness of the QOL-NPC.
  
  
  RESULTS
  A total of 487 patients (97.4 %) completed the questionnaire. The QOL-NPC comprised four domains, as follows: physical function (eight items); psychological function (five items); social function (five items); and side effects (eight items). All of the items had a lower proportion of missing data. Cronbach's alpha values of the domains ranged from 0.72 to 0.84. The split-half reliability coefficients ranged from 0.77 to 0.84. All of the intra-class correlation coefficients were > 0.8. The normed fit index, non-normed fit index, and comparative fit index were >0.89. The root mean square error of approximation was 0.097, with a 90 % confidence interval (0.093, 0.100). The domain scores of the QOL-NPC were significantly correlated with the FACT-G and FACT-H&N (P < 0.05). All of the domain scores of patients using different amounts of radiotherapy were significantly different (P < 0.001). All domain scores decreased at the completion of radiotherapy, with effect sizes ranging from -0.82 to -0.22.
  
  
  CONCLUSIONS
  The QOL-NPC is valid for measuring QOL with good reliability, validity, and responsiveness. The QOL-NPC is recommended to measure the QOL for Chinese NPC patients.
authors.affiliation: Department of Radiation Oncology, Cancer Centre, Sun Yat-sen University, Guangzhou, Guangdong Province, China.|Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong Province, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Su
authors.affiliation: Department of Biostatistics and Preventive Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China.
authors.forename: Chuan-Wei
authors.initials: CW
authors.lastname: Mo
authors.affiliation: Department of Radiation Oncology, Cancer Centre, Sun Yat-sen University, Guangzhou, Guangdong Province, China.|Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong Province, China.
authors.forename: Wan-Qin
authors.initials: WQ
authors.lastname: Cheng
authors.affiliation: Department of Radiation Oncology, Cancer Centre, Sun Yat-sen University, Guangzhou, Guangdong Province, China.|Collaborative Innovation Center for Cancer Medicine, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong Province, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Biostatistics and Preventive Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China.
authors.forename: Zu-Chun
authors.initials: ZC
authors.lastname: Wu
authors.affiliation: School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China.
authors.forename: Zhe-Li
authors.initials: ZL
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, Cancer Centre, Sun Yat-sen University, Guangzhou, Guangdong Province, China.
authors.forename: Li-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.affiliation: Department of Biostatistics and Preventive Medicine, School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China. chenxlsums@126.com.
authors.forename: Xin-Lin
authors.initials: XL
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000523:psychology*; D002277:Carcinoma; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000523:psychology* / Q000628:therapy*; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D010361:Patients / Q000523:psychology*; D016730:Program Development; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
keywords: Health-related quality of life; QOL-NPC; Reliability; Responsiveness; Validity