Predicting risk of osteoporotic and hip fracture in the United Kingdom: prospective independent and external validation of QFractureScores
BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d3651 (Published 22 June 2011) Cite this as: BMJ 2011;342:d3651
- Gary S Collins, senior medical statistician,
- Susan Mallett, senior medical statistician,
- Douglas G Altman, director, professor of statistics in medicine
- 1Centre for Statistics in Medicine, Wolfson College Annexe, University of Oxford, Oxford OX2 6UD, UK
- Correspondence to: G S Collins gary.collins{at}csm.ox.ac.uk
- Accepted 4 April 2011
Abstract
Objective To evaluate the performance of the QFractureScores for predicting the 10 year risk of osteoporotic and hip fractures in an independent UK cohort of patients from general practice records.
Design Prospective cohort study.
Setting 364 UK general practices contributing to The Health Improvement Network (THIN) database.
Participants 2.2 million adults registered with a general practice between 27 June 1994 and 30 June 2008, aged 30-85 (13 million person years), with 25 208 osteoporotic fractures and 12 188 hip fractures.
Main outcome measures First (incident) diagnosis of osteoporotic fracture (vertebra, distal radius, or hip) and incident hip fracture recorded in general practice records.
Results Results from this independent and external validation of QFractureScores indicated good performance data for both osteoporotic and hip fracture end points. Discrimination and calibration statistics were comparable to those reported in the internal validation of QFractureScores. The hip fracture score had better performance data for both women and men. It explained 63% of the variation in women and 60% of the variation in men, with areas under the receiver operating characteristic curve of 0.89 and 0.86, respectively. The risk score for osteoporotic fracture explained 49% of the variation in women and 38% of the variation in men, with corresponding areas under the receiver operating characteristic curve of 0.82 and 0.74. QFractureScores were well calibrated, with predicted risks closely matching those across all 10ths of risk and for all age groups.
Conclusion QFractureScores are useful tools for predicting the 10 year risk of osteoporotic and hip fractures in patients in the United Kingdom.
Footnotes
Contributors: GSC carried out the analysis and prepared the first draft, which was revised according to comments and suggestions from SM and DGA. GSC is guarantor.
Funding: This research received no specific grant from any funding agency in the public, commercial, or not for profit sectors.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the Trent multicentre research ethics committee.
Data sharing: No additional data available.
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