title: The Epidemiology of Hip and Major Osteoporotic Fractures in a Dutch Population of Community-Dwelling Elderly: Implications for the Dutch FRAX® Algorithm.
abstract: BACKGROUND
  Incidence rates of non-hip major osteoporotic fractures (MOF) remain poorly characterized in the Netherlands. The Dutch FRAX® algorithm, which predicts 10-year probabilities of hip fracture and MOF (first of hip, humerus, forearm, clinical vertebral), therefore incorporates imputed MOF rates. Swedish incidence rate ratios for hip fracture to MOF (Malmo 1987-1996) were used to perform this imputation. However, equality of these ratios between countries is uncertain and recent evidence is scarce. Aims were to estimate incidence rates of hip fracture and MOF and to compare observed MOF rates to those predicted by the imputation method for the Netherlands.
  
  
  METHODS
  Using hospitalisation and general practitioner records from the Dutch PHARMO Database Network (2002-2011) we calculated age-and-sex-specific and age-standardized incidence rates (IRs) of hip and other MOFs (humerus, forearm, clinical vertebral) and as used in FRAX®. Observed MOF rates were compared to those predicted among community-dwelling individuals ≥50 years by the standardized incidence ratio (SIR; 95% CI).
  
  
  RESULTS
  Age-standardized IRs (per 10,000 person-years) of MOF among men and women ≥50 years were 25.9 and 77.0, respectively. These numbers were 9.3 and 24.0 for hip fracture. Among women 55-84 years, observed MOF rates were significantly higher than predicted (SIR ranged between 1.12-1.50, depending on age). In men, the imputation method performed reasonable.
  
  
  CONCLUSIONS
  Observed MOF incidence was higher than predicted for community-dwelling women over a wide age-range, while it agreed reasonable for men. As miscalibration may influence treatment decisions, there is a need for confirmation of results in another data source. Until then, the Dutch FRAX® output should be interpreted with caution.
authors.affiliation: Utrecht Institute for Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, Netherlands.
authors.forename: Corinne
authors.initials: C
authors.lastname: Klop
authors.affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center, Utrecht, Netherlands.|Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, Netherlands.
authors.forename: Paco M J
authors.initials: PM
authors.lastname: Welsing
authors.affiliation: Utrecht Institute for Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, Netherlands.
authors.forename: Hubert G M
authors.initials: HG
authors.lastname: Leufkens
authors.affiliation: Department of General Practice and Elderly Care, VU University Medical Centre, Amsterdam, Netherlands.
authors.forename: Petra J M
authors.initials: PJ
authors.lastname: Elders
authors.affiliation: PHARMO Institute for Drug Outcomes Research, Utrecht, Netherlands.
authors.forename: Jetty A
authors.initials: JA
authors.lastname: Overbeek
authors.affiliation: Department of Internal Medicine, Viecuri Medical Centre, Venlo, Netherlands.|Department of Internal Medicine, Maastricht University Medical Centre+, Maastricht, Netherlands.|Biomedical Research Institute, University Hasselt, Hasselt, Belgium.
authors.forename: Joop P
authors.initials: JP
authors.lastname: van den Bergh
authors.affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center, Utrecht, Netherlands.
authors.forename: Johannes W J
authors.initials: JW
authors.lastname: Bijlsma
authors.affiliation: Utrecht Institute for Pharmaceutical Sciences, Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, Netherlands.|Department of Clinical Pharmacy and Toxicology, Maastricht University Medical Centre+, Maastricht, Netherlands.|MRC Lifecourse Epidemiology Unit, Southampton General Hospital, Southampton, United Kingdom.
authors.forename: Frank
authors.initials: F
authors.lastname: de Vries
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015519:Bone Density; D016208:Databases, Factual; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D058866:Osteoporotic Fractures / Q000453:epidemiology*; D012307:Risk Factors