title: Interruptions of Head and Neck Radiotherapy Across Insured and Indigent Patient Populations.
abstract: Radiotherapy for head and neck cancer is a cornerstone of care, requiring 30 to 35 days of treatment over 6 to 7 weeks. Diligent patient compliance is crucial, and unplanned treatment interruptions reduce cure rates. We studied interruption rates in private carrier-insured and Medicare-insured populations versus indigent populations served by a single academic health system.
  
  
  
  A retrospective cohort study of electronic medical and billing records was performed analyzing treatment interruptions between January 2011 and December 2014. The study included 564 patients with head and neck cancer prescribed radiotherapy and referred from clinics run by University of Texas Southwestern Medical Center (UTSW) and the Parkland Health and Hospital System (PHHS), which provides indigent care to Dallas County, Texas.
  
  
  
  Three-hundred sixteen patients (56%) had a treatment break; 114 patients missed a single session, and 202 patients missed multiple treatments. Seventy percent of PHHS patients had treatment delays compared with 47% of UTSW patients ( P < .001). The number of interrupted days in the PHHS population was nearly twice that observed in UTSW patients. PHHS patients most commonly missed treatment for nonmedical or logistical reasons. Delay was predictive for local recurrence ( P < .001) and overall survival ( P < .001). In compliant patients, there was no significant difference in local recurrence ( P = .43) or overall survival ( P = .27) across referral sites. However, among noncompliant patients, there was a higher likelihood for local recurrence in the PHHS cohort ( P = .016). Multivariable modeling suggested treatment interruption to be a key driver of outcome differences across referral sites.
  
  
  
  Survival outcomes in our at-risk population were inferior to those in patients insured by commercial carriers or Medicare. Treatment interruption predicted for poor outcome across all patients but was disproportionately experienced by at-risk patients. These results highlight cancer control needs specific to disadvantaged communities at risk for poor treatment compliance.
authors.affiliation: Department of Radiation Oncology, University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, 1265 Union Ave, Memphis, TN 38104; e-mail: dschwar4@uthsc.edu.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Thomas
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX; and University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, Memphis, TN.
authors.forename: Travis
authors.initials: T
authors.lastname: Martin
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX; and University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, Memphis, TN.
authors.forename: Ang
authors.initials: A
authors.lastname: Gao
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX; and University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, Memphis, TN.
authors.forename: Chul
authors.initials: C
authors.lastname: Ahn
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX; and University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, Memphis, TN.
authors.forename: Holly
authors.initials: H
authors.lastname: Wilhelm
authors.affiliation: Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX; and University of Tennessee Health Sciences Center-West Cancer Center, Methodist University Hospital, Memphis, TN.
authors.forename: David L
authors.initials: DL
authors.lastname: Schwartz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D008297:Male; D017057:Medically Uninsured; D006278:Medicare; D008875:Middle Aged; D009367:Neoplasm Staging; D010349:Patient Compliance; D063868:Patient Outcome Assessment; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis; D013781:Texas / Q000453:epidemiology; D014481:United States; D055815:Young Adult