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Secular Trends in Swedish Hip Fractures 1987-2002: Birth Cohort and Period Effects.

Rosengren, Björn LU ; Ahlborg, Henrik LU ; Mellström, Dan; Nilsson, Jan-Åke LU ; Björk, Jonas LU and Karlsson, Magnus LU (2012) In Epidemiology 23(4). p.623-630
Abstract
BACKGROUND: Recently, a leveling off in hip-fracture incidence has been reported in several settings, but the annual number is nonetheless predicted to increase due to the growing elderly population.



METHODS: Using Swedish national data for 1987-2002 for all inpatients 50 years or older, we examined the annual number and incidence of hip fractures and explored age, period, and cohort effects. Age adjustment was done by direct standardization, time-trend analysis by linear regression, changes in linear trends by joinpoint regression, and age-period-cohort effects by log-likelihood estimates in Poisson regression models.



RESULTS: Before 1996, the age-standardized hip fracture incidence was stable (0.1%... (More)
BACKGROUND: Recently, a leveling off in hip-fracture incidence has been reported in several settings, but the annual number is nonetheless predicted to increase due to the growing elderly population.



METHODS: Using Swedish national data for 1987-2002 for all inpatients 50 years or older, we examined the annual number and incidence of hip fractures and explored age, period, and cohort effects. Age adjustment was done by direct standardization, time-trend analysis by linear regression, changes in linear trends by joinpoint regression, and age-period-cohort effects by log-likelihood estimates in Poisson regression models.



RESULTS: Before 1996, the age-standardized hip fracture incidence was stable (0.1% per year [95% confidence interval = -0.2% to 0.5%]), and the annual number of hip fractures increased (2.1% per year [1.8% to 2.4%]). After 1996, both the age-standardized hip fracture incidence (-2.2% per year [-2.8% to -1.6%]) and the number of hip fractures (-0.9% per year [-1.5% to -0.4%]) decreased. The period + cohort effects were more marked among women than men, with a major reduction in hip fracture incidence in subsequent birth cohorts (estimated incidence rate ratio = 2.2 comparing women born 1889-1896 with 1945-1952) or periods (estimated incidence rate ratio = 1.1 comparing women living 1987-1990 with 1999-2002).



CONCLUSION: The age-standardized hip fracture incidence has decreased since 1996, more than counteracting the effects of the aging population and resulting in a decline in the annual number of hip fractures through 2002. The magnitude of the combined period and cohort effects in women seems to be of biologic importance. If this persists into older age, the annual number of hip fractures will be lower than has been projected. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Epidemiology
volume
23
issue
4
pages
623 - 630
publisher
Wolters Kluwer Health/LWW
external identifiers
  • wos:000304916900015
  • pmid:22531666
  • scopus:84862120310
ISSN
1531-5487
DOI
10.1097/EDE.0b013e318256982a
language
English
LU publication?
yes
id
6739c9a4-d163-4928-b379-80d1a0abdb56 (old id 2519056)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/22531666?dopt=Abstract
date added to LUP
2012-05-07 11:48:20
date last changed
2017-10-08 03:09:08
@article{6739c9a4-d163-4928-b379-80d1a0abdb56,
  abstract     = {BACKGROUND: Recently, a leveling off in hip-fracture incidence has been reported in several settings, but the annual number is nonetheless predicted to increase due to the growing elderly population. <br/><br>
<br/><br>
METHODS: Using Swedish national data for 1987-2002 for all inpatients 50 years or older, we examined the annual number and incidence of hip fractures and explored age, period, and cohort effects. Age adjustment was done by direct standardization, time-trend analysis by linear regression, changes in linear trends by joinpoint regression, and age-period-cohort effects by log-likelihood estimates in Poisson regression models. <br/><br>
<br/><br>
RESULTS: Before 1996, the age-standardized hip fracture incidence was stable (0.1% per year [95% confidence interval = -0.2% to 0.5%]), and the annual number of hip fractures increased (2.1% per year [1.8% to 2.4%]). After 1996, both the age-standardized hip fracture incidence (-2.2% per year [-2.8% to -1.6%]) and the number of hip fractures (-0.9% per year [-1.5% to -0.4%]) decreased. The period + cohort effects were more marked among women than men, with a major reduction in hip fracture incidence in subsequent birth cohorts (estimated incidence rate ratio = 2.2 comparing women born 1889-1896 with 1945-1952) or periods (estimated incidence rate ratio = 1.1 comparing women living 1987-1990 with 1999-2002). <br/><br>
<br/><br>
CONCLUSION: The age-standardized hip fracture incidence has decreased since 1996, more than counteracting the effects of the aging population and resulting in a decline in the annual number of hip fractures through 2002. The magnitude of the combined period and cohort effects in women seems to be of biologic importance. If this persists into older age, the annual number of hip fractures will be lower than has been projected.},
  author       = {Rosengren, Björn and Ahlborg, Henrik and Mellström, Dan and Nilsson, Jan-Åke and Björk, Jonas and Karlsson, Magnus},
  issn         = {1531-5487},
  language     = {eng},
  number       = {4},
  pages        = {623--630},
  publisher    = {Wolters Kluwer Health/LWW},
  series       = {Epidemiology},
  title        = {Secular Trends in Swedish Hip Fractures 1987-2002: Birth Cohort and Period Effects.},
  url          = {http://dx.doi.org/10.1097/EDE.0b013e318256982a},
  volume       = {23},
  year         = {2012},
}