title: Validity of the age-adjusted charlson comorbidity index on clinical outcomes for patients with nasopharyngeal cancer post radiation treatment: a 5-year nationwide cohort study.
abstract: OBJECTIVE
  To characterize the impact of comorbidity on survival outcomes for patients with nasopharyngeal carcinoma (NPC) post radiotherapy (RT).
  
  
  METHODS
  A total of 4095 patients with NPC treated by RT or RT plus chemotherapy (CT) in the period from 2007 to 2011 were included through Taiwan's National Health Insurance Research Database. Information on comorbidity present prior to the NPC diagnosis was obtained and adapted to the Charlson Comorbidity Index (CCI), Age-Adjusted Charlson Comorbidity Index (ACCI) and a revised head and neck comorbidity index (HN-CCI). The prevalence of comorbidity and the influence on survival were calculated and analyzed.
  
  
  RESULTS
  Most of the patients (75%) were male (age 51±13 years) and 2470 of them (60%) had at least one comorbid condition. The most common comorbid condition was diabetes mellitus. According to these three different comorbidity index (CCI, ACCI and HN-CCI), higher scores were associated with worse overall survival (P< 0.001). The Receiver Operating Characteristic (ROC) curve was used to assess the discriminating ability of CCI, AACI and HN-CCI scores and it demonstrated the predictive ability for mortality with the ACCI (0.693, 95% CI 0.670-0.715) was superior to that of the CCI (0.619, 95% CI 0.593-0.644) and HN-CCI (0.545, 95%CI 0.519-0.570).
  
  
  CONCLUSIONS
  Comorbidities greatly inﬂuenced the clinical presentations, therapeutic interventions, and outcomes of patients with NPC post RT. Higher comorbidity index scores accurately was associated with worse survival. The ACCI seems to be a more appropriate prognostic indicator and should be considered in further clinical studies.
authors.affiliation: Department of Radiation Oncology, Chi-Mei Medical Center, Tainan, Taiwan; Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Ching-Chieh
authors.initials: CC
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Pingtung Christian Hospital, Pingtung, Taiwan.
authors.forename: Po-Chun
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Department of Medical Research, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Hsu
authors.affiliation: Department of Otolaryngology, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Shih-Lun
authors.initials: SL
authors.lastname: Chang
authors.affiliation: Department of Otolaryngology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan; Center for Clinical Epidemiology and Biostatistics, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan; Cancer Center, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan; School of Medicine, Tzu Chi University, Hualian, Taiwan.
authors.forename: Ching-Chih
authors.initials: CC
authors.lastname: Lee
mesh_terms: D017677:Age Distribution; D002277:Carcinoma; D015331:Cohort Studies; D003131:Combined Modality Therapy; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology* / Q000532:radiotherapy; D011379:Prognosis; D012372:ROC Curve; D016019:Survival Analysis; D013624:Taiwan / Q000453:epidemiology