title: Repeated measures analysis of patient-reported outcomes in prostate cancer after abiraterone acetate.
abstract: BACKGROUND
  Metastatic castration-resistant prostate cancer (mCRPC) is typically associated with declining health-related quality of life (HR-QoL).
  
  
  OBJECTIVE
  To assess patient experience with abiraterone acetate (hereafter abiraterone) plus prednisone longitudinally.
  
  
  METHODS
  COU-AA-302 was a phase 3, multinational, randomized, double-blind study that enrolled asymptomatic or mildly symptomatic, chemotherapy-naïve patients with mCRPC. Patients were randomized to 1 g abiraterone daily plus 5 mg prednisone BID (n = 546) or placebo plus prednisone (n = 542) in continuous 28-day cycles. Patient-reported outcomes (PROs) were collected using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire, consisting of 4 well-being subscales (physical, social/family, emotional, functional) and a prostate cancer-specific subscale (PCS). The trial outcome index (TOI) is a composite of the physical well-being, functional well-being, and PCS scores. Least squares mean change from baseline at each cycle up to 1 year (cycle13) was compared between treatment arms using a mixed-effects model for repeated measures, which assumed that data were "missing at random." A pattern-mixture model (PMM) with multiple imputation was performed to address the assumption that data were "missing not at random."
  
  
  RESULTS
  Significant differences favoring abiraterone-prednisone were observed for FACT-P total, TOI, and PCS scores, and for all well-being subscales except social/family well-being over the first year of treatment. These results were supported by the PMM with multiple imputation.
  
  
  CONCLUSIONS
  Attrition after 1 year limited our ability to analyze the PRO data beyond that time point.
  
  
  CONCLUSIONS
  Abiraterone-prednisone confers sustained HR-QoL benefits over the course of treatment.
authors.affiliation: Robert H Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois, USA. d-cella@northwestern.edu.
authors.forename: David
authors.initials: D
authors.lastname: Cella
authors.affiliation: Janssen Research & Development, Spring House, Pennsylvania, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Li
authors.affiliation: Janssen Global Services, Raritan, New Jersey, USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Li
authors.affiliation: Janssen Research & Development, San Diego, California, USA.
authors.forename: Thian
authors.initials: T
authors.lastname: Kheoh
authors.affiliation: Janssen Global Services, Raritan, New Jersey, USA.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Todd
authors.affiliation: Departmnet of Medicine, The University of North Carolina at Chapel Hill, North Carolina, USA.
authors.forename: Ethan
authors.initials: E
authors.lastname: Basch
keywords: abiraterone acetate; longitudinal; patient-reported outcomes; prostate cancer; quality of life; repeated measures