title: Health-related quality of life in lung cancer survivors: Latent class and latent transition analysis.
abstract: BACKGROUND
  Health-related quality of life (HRQOL) heterogeneity among cancer survivors may mask subgroups (classes) with different limitations and long-term outcomes. The authors determined the HRQOL classes that exist among lung cancer survivors, examined transitions among those classes over time, and compared survival outcomes of patients according to the classes present in the initial phase of care.
  
  
  METHODS
  Lung cancer survivors in the Cancer Care Outcomes Research and Surveillance Consortium completed EuroQol 5-domain quality-of-life questionnaires 4.8 months (initial phase) and >1 year (survivorship phase) after diagnosis (n = 1396). Latent class analysis and latent transition analysis were used to determine HRQOL classes and transitions across time. Correlates of class membership were tested using multinomial logistic regression. Kaplan-Meier and Cox regression analyses were used to compare survival across class membership.
  
  
  RESULTS
  Latent class analysis identified 4 classes at diagnosis and follow-up: 1) poor HRQOL, 2) pain-dominant impairment, 3) mobility/usual activities impairment, and 4) good HRQOL. Probabilities of remaining in the same class were .87, .85, .82, and .73 for classes 4, 1, 3, and 2, respectively. Younger age, lower income, lower education, comorbidities, and a history of depression/emotional problems were associated with a greater likelihood of being in classes 1, 2, or 3 at follow-up. Patients in classes 1 and 3 had significantly lower median survival estimates than patients in class 4 (4.8 years, 3.8 years, and 5.5 years, respectively; P < .001).
  
  
  CONCLUSIONS
  Examining the heterogeneity of HRQOL in lung cancer populations allows the identification of classes with different limitations and long-term outcomes and, thus, guides tailored and patient-centered provision of supportive care.
authors.affiliation: School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Kenzik
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Martin
authors.forename: Mona N
authors.initials: MN
authors.lastname: Fouad
authors.forename: Maria
authors.initials: M
authors.lastname: Pisu
mesh_terms: D000368:Aged; D005260:Female; D006304:Health Status; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D016016:Proportional Hazards Models; D011788:Quality of Life; D011795:Surveys and Questionnaires; D017741:Survivors
keywords: health-related quality of life; latent class; lung cancer; survivor; transition