Full Length ArticleFracture incidence and secular trends between 1989 and 2013 in a population based cohort: The Rotterdam Study
Introduction
Fractures of the hip, wrist and pelvis are among the most common osteoporotic fractures [1] affecting hundreds of millions of people worldwide. In the European Union, the annual costs of all osteoporotic fractures has been estimated at €37 billion [2] in 2010, of which 54% of the costs are attributed to hip fractures [2]. Due to the aging of industrialized societies, the incidence of osteoporosis and fragility fractures is expected to increase in the years to come [3, 4].
However, not all studies show a clear increase of fractures rates. For instance, previous studies have yielded conflicting perspectives indicating that the incidence of hip fracture has either increased, plateaued, or even decreased in the last decades [[5], [6], [7], [8], [9], [10]]. Such discrepancies may be explained by multiple factors, including: secular periods in which the fractures occur, changes in clinical practice and drug prescription or compliance, distribution of age and demographics within age and sex strata, migrations and/or geographical origin of the report [7]. For example, studies performed in the USA have reported a decline in the incidence of hip fractures between 1980 and 2000 [8, 9]. In contrast, in the Netherlands, an initial linear increase in hip fracture incidence during the period between 1972 and 1987 [10] is now proposed to have plateaued during the following decades [11]. Moreover, recent information on incidence rates and trends for other sites of non-vertebral fractures is currently lacking despite that non-hip fractures are also associated with higher disability [12] and mortality [13] rates. Depiction of robustly-assessed overall and site-specific fracture trends is important to estimate the burden of osteoporosis and to establish proper and cost-effective prevention strategies.
Part of delineating cost-effective prevention strategies involves determining the predictive ability of fracture risk factors in time. Although fractures have a multifactorial background, apart from age, low BMI and falls, a low bone mineral density (BMD) remains one of the most important risk factors. Studies have shown that the reduction of femoral neck (FN-) BMD is essentially linear over time, comprising ~1–2% of baseline BMD per year [14]. It is well established that BMD can predict fracture risk over a period of 5–10 years [15, 16], but little is known [17, 18] about the predictive value of BMD over longer periods.
Altogether, our aims were to 1) evaluate the association between BMD at baseline (both continuously and using clinical cutoffs) and fracture risk over a long time period, 2) estimate the incidence of non-vertebral fractures (overall and site-specific) during 23 years of follow-up and 3) evaluate whether incidence rates have changed during two subsequent secular follow-up periods. All analyses were performed for the total group and stratified by sex, considering the well-established sexual differences in fracture risk.
Section snippets
Study population
Our study included participants from the Rotterdam Study, an ongoing population-based prospective cohort comprising 14,926 Dutch individuals aged 45 years and older examined across three population sets [19]. At its start in 1990, a total of 7983 participants aged 55 years and older were included in the initial study wave (RSI). The cohort was expanded in 2000 with 3011 participants (RSII) aged 55 years and older; and in 2006 with 3932 participants (RSIII) aged 45 years and older, or who had
Statistical analyses
All analyses were performed for the total group of participants and stratified by sex, considering the well-established sex differences in fracture risk [[22], [23], [24]]. First, Cox proportional hazard models adjusted for age at baseline and cohort were used to estimate the hazard ratio (HR) of first fracture associated with 1 SD decrease in FN-BMD across 1) all non-vertebral fractures, 2) for specific types of fractures and 3) all non-vertebral fractures in groups of subjects classified by
Characteristics of the study population
Fig. 1 is a flow diagram describing the selection of study participants. At baseline, the mean (±SD) age of the participants was 64.7 (±9.4) years for men and 66.5 (±10.9) years for women. The prevalence of osteoporosis (BMD T-score <−2.5) was 10.8% in women and 6.6% in men. The prevalence increased exponentially with age for all types of fractures but this relation is less prominent for wrist fractures (Fig. 2). Above the age of 85 years, 40.9% of the women and 31.7% of the men had
Discussion
In this population-based prospective cohort, a single FN-BMD measurement at baseline remains a strong predictor of incident non-vertebral fragility fractures over a period of 20 years. The overall incidence rate of suffering non-vertebral fractures was 21.1 per 1000 PY [95%CI: 20.3–21.9] with a higher incidence rate in women than in men. The most frequent non-vertebral fractures in elderly men and women continues to be fractures of the hip, wrist, proximal humerus and hand, with most events
Conclusion
In conclusion, BMD remains a strong predictor of hip and non-vertebral fractures over 20 years in both men and women. The majority of fractures continue to occur above the osteoporosis threshold emphasizing the need to improve the screening of osteopenic patients. Most importantly, we established there are no difference in fracture trends between the periods of 1989–2001 and 2001–2013, welcoming active actions seeking to improve the diagnoses, treatment and prevention strategies to this costly
Acknowledgements and statement of authors' contributions to manuscript
We gratefully acknowledge the contribution of the participants of the Rotterdam Study, research assistants, the general practitioners, hospitals and pharmacies in Rotterdam.
Funding sources
The Rotterdam Study is funded by Erasmus Medical Center and Erasmus University Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (014-93-015; RIDE2, RIDE), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Union Seventh Framework Programme (FP7/2007–2013) under grant agreement No. 601055, VPH-DARE@IT, and the Municipality of Rotterdam.
References (46)
- et al.
Epidemiology and outcomes of osteoporotic fractures
Lancet
(2002) - et al.
Fracture incidence and association with bone mineral density in elderly men and women: the Rotterdam Study
Bone
(2004) - et al.
Gender differences in the incidence of and risk factors for hip fracture: a 16-year longitudinal study in a southern European population
Maturitas
(2017) - et al.
Beyond hip: importance of other nonspinal fractures
Am. J. Med.
(2007) - et al.
Epidemiology of extremity fractures in the Netherlands
Injury
(2017) - et al.
Geographic differences in fractures among women
Women's Health (Lond. Engl.)
(2012) - et al.
Osteoporosis in the European Union: medical management, epidemiology and economic burden. A report prepared in collaboration with the International Osteoporosis Foundation (IOF) and the European Federation of Pharmaceutical Industry Associations (EFPIA)
Arch. Osteoporos.
(2013) - et al.
World-wide projections for hip fracture
Osteoporos. Int.
(1997) - et al.
Incidence and economic burden of osteoporosis-related fractures in the United States, 2005–2025
J. Bone Miner. Res.
(2007) - et al.
Secular trend in the incidence of hip fracture in Catalonia, Spain, 2003–2014
Age Ageing
(2016)
Continued decline in hip fracture incidence in Norway: a NOREPOS study
Osteoporos. Int.
Temporal and geographic variation in hip fracture rates for people aged 65 or older, New York State, 1985–1996
Am. J. Orthop. (Belle Mead NJ)
Increasing hip fracture incidence in California Hispanics, 1983 to 2000
Osteoporos. Int.
The incidence of hip fractures in The Netherlands
Neth. J. Med.
Developments of the incidence of osteoporosis in The Netherlands: a PHARMO study
Pharmacoepidemiol. Drug Saf.
Disability after clinical fracture in postmenopausal women with low bone density: the fracture intervention trial (FIT)
Osteoporos. Int.
Population-wide impact of non-hip non-vertebral fractures on mortality
J. Bone Miner. Res.
Determinants of bone loss from the femoral neck in women of different ages
J. Bone Miner. Res.
Relative contributions of bone density, bone turnover, and clinical risk factors to long-term fracture prediction
J. Bone Miner. Res.
The ability of a single BMD and fracture history assessment to predict fracture over 25 years in postmenopausal women: the study of osteoporotic fractures
J. Bone Miner. Res.
How to predict fragility fracture beyond 10 years? The OFELY study
J. Clin. Endocrinol. Metab.
The Rotterdam Study: 2018 update on objectives, design and main results
Eur. J. Epidemiol.
Updated data on proximal femur bone mineral levels of US adults
Osteoporos. Int.
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