title: Risk of hospitalisation and death due to bone fractures after breast cancer: a registry-based cohort study.
abstract: BACKGROUND
  Bone fractures may have an impact on prognosis of breast cancer. The long-term risks of bone fracture in breast cancer patients have not been thoroughly studied.
  
  
  METHODS
  Poisson regression was used to investigate the incidence of hospitalisation due to bone fracture comparing women with and without breast cancer based on Swedish National registers. Cox regression was used to investigate the risk of being hospitalised with bone fracture, and subsequent risk of death, in a regional cohort of breast cancer patients.
  
  
  RESULTS
  For breast cancer patients, the 5-year risk of bone fracture hospitalisation was 4.8% and the 30-day risk of death following a bone fracture hospitalisation was 2.0%. Compared with the general population, breast cancer patients had incidence rate ratios of 1.25 (95% CI: 1.23-1.28) and 1.18 (95% CI: 1.14-1.22) for hospitalisation due to any bone fracture and hip fracture, respectively. These ratios remained significantly increased for 10 years. Comorbidities (Charlson Comorbidity Index ⩾1) were associated with the risk of being hospitalised with bone fracture. Women taking aromatase inhibitors were at an increased risk as compared with women taking tamoxifen (HR=1.48; 95% CI: 0.98-2.22). Breast cancer patients hospitalised for a bone fracture showed a higher risk of death (HR=1.83; 95% CI: 1.50-2.22) compared with those without bone fracture.
  
  
  CONCLUSIONS
  Women with a previous breast cancer diagnosis are at an increased risk of hospitalisation due to a bone fracture, particularly if they have other comorbidities.
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.|Department of Health Sciences, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, Monza 20126, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Colzani
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Mark
authors.initials: M
authors.lastname: Clements
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Anna L V
authors.initials: AL
authors.lastname: Johansson
authors.affiliation: Department of Oncology and Pathology, Karolinska University Hospital, Karolinska Institutet, P.O. Box 260, Stockholm SE-171 76, Sweden.
authors.forename: Annelie
authors.initials: A
authors.lastname: Liljegren
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Judith
authors.initials: J
authors.lastname: Brand
authors.affiliation: Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm SE-171 77, Sweden.|Swedish Agency for Health Technology Assessment and Assessment of Social Services, Stockholm SE-102 33, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Adolfsson
authors.affiliation: Department of Oncology and Pathology, Karolinska University Hospital, Karolinska Institutet, P.O. Box 260, Stockholm SE-171 76, Sweden.
authors.forename: Tommy
authors.initials: T
authors.lastname: Fornander
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Hall
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Nobelsväg 12A, Stockholm SE-171 77, Sweden.
authors.forename: Kamila
authors.initials: K
authors.lastname: Czene
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000150:complications*; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000209:etiology / Q000401:mortality / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D016012:Poisson Distribution; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology