title: Challenges associated with longitudinal survivorship research: attrition and a novel approach of reenrollment in a 6-year follow-up study of older breast cancer survivors.
abstract: BACKGROUND
  Breast cancer is the most common type of cancer among older women. The vast majority of women with breast cancer become long-term survivors.
  
  
  METHODS
  We selected a convenience sample of women with: (1) stage I-IIIa disease, (2) age 65-years or older, and (3) permission from physician to contact. Data were collected over 6-years of follow-up from consenting patients' medical records, telephone interviews, and the National Death Index. Before year 4 of follow-up we attempted to relocate women lost to follow-up using a single protocol and when successful, invited them to reenroll in the study. In this secondary data-analysis, baseline characteristics were compared among subjects with continuous follow-up, those who reenrolled, died, or were lost to follow-up.
  
  
  RESULTS
  Among 660 subjects, 177 had complete follow-up, 182 reenrolled after a period of non-participation, 171 died, and 130 were lost to follow-up. No important differences were found between reenrolled women and those with continuous follow-up or those lost to follow-up. There were nominal differences in age and comorbidity among women lost to follow-up compared to those with complete follow-up.
  
  
  CONCLUSIONS
  This study highlights challenges in longitudinal research of cancer survivorship, specifically the potential benefit of reenrollment.
  
  
  CONCLUSIONS
  Our findings provide a novel and promising approach to surmount some of the challenges in longitudinal research aimed at enhancing knowledge and the overall cancer survivorship experience of older adults.
authors.affiliation: Boston University Schools of Medicine, Boston University Medical Center, 88 East Newton Street, Robinson 2, Boston, MA 02118, USA. kmclough@bu.edu
authors.forename: Kerri M
authors.initials: KM
authors.lastname: Clough-Gorr
authors.forename: Aliza K
authors.initials: AK
authors.lastname: Fink
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Silliman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007258:Informed Consent; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008603:Mental Health; D009367:Neoplasm Staging; D018579:Patient Selection; D010821:Physicians, Family; D016019:Survival Analysis; D017741:Survivors; D013997:Time Factors; D014481:United States