title: Survival rate in nasopharyngeal carcinoma improved by high caseload volume: a nationwide population-based study in Taiwan.
abstract: BACKGROUND
  Positive correlation between caseload and outcome has previously been validated for several procedures and cancer treatments. However, there is no information linking caseload and outcome of nasopharyngeal carcinoma (NPC) treatment. We used nationwide population-based data to examine the association between physician case volume and survival rates of patients with NPC.
  
  
  METHODS
  Between 1998 and 2000, a total of 1225 patients were identified from the Taiwan National Health Insurance Research Database. Survival analysis, the Cox proportional hazards model, and propensity score were used to assess the relationship between 10-year survival rates and physician caseloads.
  
  
  RESULTS
  As the caseload of individual physicians increased, unadjusted 10-year survival rates increased (p < 0.001). Using a Cox proportional hazard model, patients with NPC treated by high-volume physicians (caseload ≥ 35) had better survival rates (p = 0.001) after adjusting for comorbidities, hospital, and treatment modality. When analyzed by propensity score, the adjusted 10-year survival rate differed significantly between patients treated by high-volume physicians and patients treated by low/medium-volume physicians (75% vs. 61%; p < 0.001).
  
  
  CONCLUSIONS
  Our data confirm a positive volume-outcome relationship for NPC. After adjusting for differences in the case mix, our analysis found treatment of NPC by high-volume physicians improved 10-year survival rate.
authors.affiliation: Department of Radiation Oncology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan.
authors.forename: Ching-Chih
authors.initials: CC
authors.lastname: Lee
authors.forename: Tze-Ta
authors.initials: TT
authors.lastname: Huang
authors.forename: Moon-Sing
authors.initials: MS
authors.lastname: Lee
authors.forename: Yu-Chieh
authors.initials: YC
authors.lastname: Su
authors.forename: Pesus
authors.initials: P
authors.lastname: Chou
authors.forename: Shih-Hsuan
authors.initials: SH
authors.lastname: Hsiao
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Chiou
authors.forename: Hon-Yi
authors.initials: HY
authors.lastname: Lin
authors.forename: Sou-Hsin
authors.initials: SH
authors.lastname: Chien
authors.forename: Shih-Kai
authors.initials: SK
authors.lastname: Hung
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000401:mortality* / Q000628:therapy; D059248:Chemoradiotherapy / Q000379:methods; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000401:mortality* / Q000628:therapy; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000379:methods; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate; D013624:Taiwan; D016896:Treatment Outcome; D016526:Workload