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External validity of a population-based study on osteoporosis and fracture

Wihlborg, Axel; Åkesson, Kristina LU and Gerdhem, Paul (2014) In Acta Orthopaedica 85(4). p.433-437
Abstract
Background and purpose-Little is known about the characteristics of non-participants in epidemiological studies. We evaluated external validity by comparing fracture and mortality rate in participants and non-participants in a longitudinal study on risk factors for fracture. Methods - 1,604 randomly selected women, 75 years of age, were invited to attend a study on osteoporosis and fracture. 1,044 women attended the study (participants) and 560 women did not participate (non-participants). Fracture data for all were obtained prospectively from radiographic records. Mortality data were obtained through the population register. Mean follow-up was 13 (11-15) years. Cumulative survival was compared with the log-rank test. Fracture incidence... (More)
Background and purpose-Little is known about the characteristics of non-participants in epidemiological studies. We evaluated external validity by comparing fracture and mortality rate in participants and non-participants in a longitudinal study on risk factors for fracture. Methods - 1,604 randomly selected women, 75 years of age, were invited to attend a study on osteoporosis and fracture. 1,044 women attended the study (participants) and 560 women did not participate (non-participants). Fracture data for all were obtained prospectively from radiographic records. Mortality data were obtained through the population register. Mean follow-up was 13 (11-15) years. Cumulative survival was compared with the log-rank test. Fracture incidence rates per 1,000 person-years were compared with Mann-Whitney U-tests. In addition, fracture comparisons were made with the cumulative incidence function and Gray's test. Results - 454 participants (44%) died during the follow-up, as compared to 372 of the non-participants (66%) (p < 0.001). The fracture incidence rate for any type of fracture was 43 for participants and 47 for non-participants (p = 1.0). The fracture incidence rate for typical osteoporotic fracture was 36 for participants and 39 for non-participants (p = 0.6). The corresponding values for distal forearm fracture were 11 and 7 (p = 0.002), they were 8 and 9 for proximal humerus fracture (p = 0.9), 13 and 10 for vertebral fracture (p = 0.007), 15 and 18 for hip fracture (p = 0.8), and they were 6 and 5 for pelvic fracture (p = 0.3). The cumulative incidence function confirmed the results. Interpretation - Our findings suggest that participants had a lower mortality rate than non-participants. Distal forearm and vertebral fractures were more frequent in participants. However, the external validity for fractures in general appeared to be satisfactory. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acta Orthopaedica
volume
85
issue
4
pages
433 - 437
publisher
Taylor & Francis
external identifiers
  • wos:000340108300016
  • scopus:84904298575
ISSN
1745-3682
DOI
10.3109/17453674.2014.920987
language
English
LU publication?
yes
id
861fc922-d5fd-4809-8add-f6ec6374f06e (old id 4659543)
date added to LUP
2014-10-01 07:23:35
date last changed
2017-09-03 04:18:52
@article{861fc922-d5fd-4809-8add-f6ec6374f06e,
  abstract     = {Background and purpose-Little is known about the characteristics of non-participants in epidemiological studies. We evaluated external validity by comparing fracture and mortality rate in participants and non-participants in a longitudinal study on risk factors for fracture. Methods - 1,604 randomly selected women, 75 years of age, were invited to attend a study on osteoporosis and fracture. 1,044 women attended the study (participants) and 560 women did not participate (non-participants). Fracture data for all were obtained prospectively from radiographic records. Mortality data were obtained through the population register. Mean follow-up was 13 (11-15) years. Cumulative survival was compared with the log-rank test. Fracture incidence rates per 1,000 person-years were compared with Mann-Whitney U-tests. In addition, fracture comparisons were made with the cumulative incidence function and Gray's test. Results - 454 participants (44%) died during the follow-up, as compared to 372 of the non-participants (66%) (p &lt; 0.001). The fracture incidence rate for any type of fracture was 43 for participants and 47 for non-participants (p = 1.0). The fracture incidence rate for typical osteoporotic fracture was 36 for participants and 39 for non-participants (p = 0.6). The corresponding values for distal forearm fracture were 11 and 7 (p = 0.002), they were 8 and 9 for proximal humerus fracture (p = 0.9), 13 and 10 for vertebral fracture (p = 0.007), 15 and 18 for hip fracture (p = 0.8), and they were 6 and 5 for pelvic fracture (p = 0.3). The cumulative incidence function confirmed the results. Interpretation - Our findings suggest that participants had a lower mortality rate than non-participants. Distal forearm and vertebral fractures were more frequent in participants. However, the external validity for fractures in general appeared to be satisfactory.},
  author       = {Wihlborg, Axel and Åkesson, Kristina and Gerdhem, Paul},
  issn         = {1745-3682},
  language     = {eng},
  number       = {4},
  pages        = {433--437},
  publisher    = {Taylor & Francis},
  series       = {Acta Orthopaedica},
  title        = {External validity of a population-based study on osteoporosis and fracture},
  url          = {http://dx.doi.org/10.3109/17453674.2014.920987},
  volume       = {85},
  year         = {2014},
}