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Epidemiology of osteoporosis-related fractures in France: A literature review
Joint Bone Spine 77 (2010) 546–551
Review
Epidemiology of osteoporosis-related fractures in France: A literature review Desmond Curran a , Milka Maravic b,∗ , Philippe Kiefer c , Valérie Tochon c , Patrice Fardellone d a
Omega Research, 189, Shanliss Road, Santry, Dublin 9, Ireland Département d’information médicale, hôpital Léopold-Bellan, 19–21, rue Vercingétorix, 75674 Paris cedex 14, France c AMGEN France, 62, boulevard Victor-Hugo, 92523 Neuilly-sur-Seine cedex France d Rheumatology Department, University Hospital Amiens, place Victor-Pauchet, 80054 Amiens cedex 1, France b
a r t i c l e
i n f o
Article history: Accepted 3 February 2010 Available online 7 April 2010 Keywords: Osteoporosis Fracture France Epidemiology Postmenopausal
a b s t r a c t Objectives: To evaluate the health implications and economic burden on society of osteoporotic fractures as a major source of morbidity and mortality in the ageing population. Methods: We have summarised the findings of a literature review of French studies published between 1960 and 2009, characterised the epidemiology of osteoporosis and osteoporotic fractures, and predicted future trends. Results: Published data for France supported the observation that osteoporosis is under-diagnosed in many countries. The incidence of fracture increased exponentially with age, alongside a concurrent decrease in bone mineral density, a risk factor for fracture. Combined with a projected rise in the French elderly population, this poses a significant burden for the future. The incidence of fracture was high in the osteopenic population; consequently, fragility fractures may be underestimated if reports focus on osteoporotic women only. As in many other countries, French data revealed that women have a higher incidence of osteoporotic fractures than men, although mortality from hip fracture was higher in men. Discussion: Due to ageing of the population, an increase in the number of people suffering from fractures is predicted over the next few decades unless preventative action is taken, highlighting the need for improved diagnosis and screening in postmenopausal women. © 2010 Société franc¸aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.
1. Introduction Osteoporotic fractures are a major source of morbidity and mortality in the ageing population and place a significant health and economic burden on society [1]. Osteoporosis is a systemic skeletal disease characterised by low bone mass and micro-architectural deterioration, with a consequent increase in bone fragility and susceptibility to fracture [1]. In 1994, a World Health Organisation (WHO) expert panel defined diagnostic criteria for osteoporosis on the basis of the measurement of bone mineral density (BMD) [2]. The most important cause of osteoporosis is the gradual bone loss that occurs after the menopause [2]. Clinically, osteoporosis is often first recognised by the occurrence of low-trauma fractures; the three most frequent are vertebral, distal forearm and hip fractures [1]. Fractures are associated with increased mortality and often result in significant morbidity, impacting on quality of life. Hip fractures are particularly serious; in a prospective study of 1000 consecutive admissions for hip fracture in Britain (average
∗ Corresponding author. Phone: 33 1 40 48 68 34; Fax: 33 1 40 48 68 34. E-mail addresses: [email protected] (D. Curran), [email protected] (M. Maravic), [email protected] (P. Kiefer), [email protected] (V. Tochon), [email protected] (P. Fardellone).
age 79), mortality at 12 months was 33% and 15% of patients died without being discharged from hospital [3]. It is estimated that 60% of the global burden of osteoporosis is accounted for by non-hip fractures [4]. The incidence of osteoporosis-related fractures rises steeply with increasing age, with hip fracture incidence rates increasing exponentially [5]. Similarly, there is a strong association with gender: the female-to-male ratio of hip fracture is greater than 2:1 in people over 50 years of age [6]. The worldwide health and economic burden of osteoporosis is likely to increase in the future, as improvements in life expectancy will lead to a growing population of elderly people with a high risk of fracture [4,7]. In the EU, the population of people aged more than 65 years in 15 member states is predicted to increase from 58 million in 1995 to 108 million in 2040 [1]. In particular, the population aged more than 80 years, in whom the incidence of osteoporotic fracture is greatest, will grow from 8.9 million women and 4.5 million men in 1995 to 26.4 million women and 17.4 million men in 2050 [1]. A concurrent decline in the population of working age during this time, predicted to decrease from 234 million in 2010 to 172 million in 2050, will lead to a disproportionate increase in the burden of osteoporosis to society [1]. Recent studies have shown that age-specific rates of osteoporosis fractures might be declining or stabilising [5,8,9]; however, due
1297-319X/$ – see front matter © 2010 Société franc¸aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2010.02.006
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to ageing of the population, the absolute number of fractures is still expected to increase [8–10]. In the EU, the number of hip fractures occurring each year is expected to increase by 135% over the next 50 years from 414,000 to 972,000, and the number of vertebral fractures is predicted to increase by 57%, rising from 23.7 million in the year 2000 to 37.3 million in 2050 [1]. Since these calculations were not adjusted for secular trends, they are likely to underestimate the true increase in fractures [1,7]. This literature review focused on osteoporosis in postmenopausal women in France, with the aim of drawing together information about the epidemiology of osteoporosis and osteoporotic fractures in France and projecting future trends. 2. Literature search The search focused on epidemiology. The epidemiological endpoints of interest were: current and projected demographic trends in France, incidence and prevalence of low BMD, incidence and prevalence of osteoporotic fracture, and incidence of mortality. Information on the under-reporting of osteoporosis and on regional variations within France was also reviewed. Medline was searched from 1960 to 2009 using combinations of the following keywords (in French and English): osteoporosis, fracture, cost, economic impact, menopause, postmenopausal, epidemiology and country (e.g. France or French). The terms country and osteoporosis or fracture were included in all searches (e.g. France, fracture, cost). Searches of conference abstract books and multiple web searches were performed using the same keywords. Titles and abstracts were reviewed to decide whether an article/text should be examined further. Reports were reviewed if they provided details on: (i) incidence or prevalence of fractures (or osteoporosis) and/or subsequent trends; (ii) resource use (e.g. hospital stay, specialist and general practitioner [GP] visits, drugs, transport) and/or associated costs; (iii) patient-reported outcomes, follow-up or mortality of patients. Furthermore, papers referenced in these publications were retrieved if they were thought to substantially contribute to that publication and provide additional information. A report summarising the findings of the review was circulated to French experts in the field of osteoporosis to check for completeness and accuracy. 3. Results 3.1. French demographic trends Over the past 30 years, the population of mainland France has grown from 50.5 million inhabitants in 1970 to 58.5 million in 2000 [11] and to 61.8 million in 2007 (Table 1) [12]. In particular, the number of people aged 60 years and above (i.e. at high risk of osteoporosis-related fractures) is increasing. The population aged over 60 rose from 9.1 to 12.1 million between 1970 and 2000, and is projected to rise to between 19.5 and 20.4 million by 2030 as the baby-boom generation ages [11]. This means that by 2030 one person in three will be aged 60 years or over, compared with one in five in 2000. The number of people aged over 75 will effectively double between 2000 and 2030; increasing from 4.2 to 8.3 million [11]. Table 1 The French mainlanda population by age and sex in 2007 [12]. Age group (years)
Men (N)
Women (N)
Total (N)
0–59 60–74 ≥ 75
24,244,193 3,753,201 1,903,199
24,259,207 4,282,239 3,328,961
48,503,400 8,035,440 5,232,160
Total
29,900,593
31,870,407
61,771 000
a
Includes Corsica, excludes overseas regions and territories.
Fig. 1. Average bone mineral density by age group for 7598 women from the Epidemiology of Osteoporosis (EPIDOS) Study [13].
Overall, the population of mainland France is expected to increase to 64.5 million in 2040 [11]. 3.2. Bone mineral density evolution Low BMD has been shown to be a risk factor for fracture [2]. Using data from the Epidemiology of Osteoporosis (EPIDOS) prospective study, Schott et al. demonstrated a decrease in BMD in association with increasing age in a cohort of 7598 women aged 75 or over in five French cities (Fig. 1) [13]. The hip fracture risk increased 1.6 times (95% CI: 1.2–2.0) for each S.D. decrease in whole-body BMD. According to WHO definitions, only 6.5% of the women who participated in the EPIDOS study were considered to have normal bone mass, 46% were considered to have osteopenia and 48% were diagnosed as osteoporotic [13]. Although the incidence of hip fracture is high in osteoporotic women, many hip fractures occur in women whose BMD is above a T-score of −2.5 S.D. [14,15]. In the EPIDOS cohort, the incidence of hip fracture per 1000 woman-years was highest in osteoporotic women (16.4; 95% CI: 16.4–16.5), but was also greater in osteopenic women (5.4; 95% CI: 5.3–5.5) than in women with normal BMD (1.1, 95% CI: 1.0–1.2) [13]. A significant risk of fracture in the osteopenic population was also demonstrated in a large population-based cohort (os des femmes de Lyon [OFELY]) of 671 postmenopausal women followed for a median of 9.1 years [15]. In this study, all peripheral fractures were confirmed radiographically and vertebral fractures were identified by the Genant method. Forty-four percent of incident fractures occurred in osteoporotic women, 48% in osteopenic women and 8% in women with normal BMD, in a population where 21% were osteoporotic, 48% were osteopenic and 31% had normal BMD. The overall incidence of fracture in this study was 19 per 1000 woman-years [15]. Given the risk of fracture in the osteopenic population, fragility fractures may be underestimated if reports focus on osteoporotic women only [15]. 3.3. Age- and gender-specific incidence/prevalence of fractures 3.3.1. Hip fracture Data from several French studies show that the incidence of hip fracture is higher in women with osteoporosis, increases exponentially with age, and is higher in females than males (Table 2). In the EPIDOS cohort, the incidence of hip fracture per 1000 woman-years
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Table 2 Age- and gender-specific hip fracture incidence rates in France (per 10,000 person-years). Study
Age class (years)
a
Schott et al. 1998 [13]
75–80
b
Baudoin et al. 1996 [6]
Men
> 80
b
c
Baudoin et al. 1996 [6]
Maravic et al. 2005 [17]
d
Blachier 1999 [39]
Note
125
EPIDOS study
200
≥ 20
5.8
16.8
Surveys 2–7
≥ 50 ≥ 50 ≥ 65 ≥ 65 ≥ 65
13.4 13.6 26.2 27.8 27.8
37.6 42.6 67.9 77.9 76.1
Surveys 2–7 Death certificates Surveys 2–7 Death certificates Survey 1
≥ 20
5.8
16.8
Surveys 2–7
≥ 60 ≥ 80
19.7 71.2
53.4 154.9
Surveys 2–7 Surveys 2–7
46–65
3.8
3.7
66–80 ≥ 81
19.0 125.6
38.4 258.5
60
French National Hospital Database
50
> 80 Ribot et al. 1990 [40]
Women
150
> 50
5.1
21.3
Toulouse
> 50
4.9
23.8
Île-de-France
a
Incidence for a subset of 3043 women from the EPIDOS study classified as osteoporotic; estimated per 1000 woman-years and multiplied by 10. Survey 1 includes national data collected in France between 1978–1982; Surveys 2–7 include data collected from six surveys carried out in five different regions of France between 1986–1992; Incidence of hip fractures declared on death certificates. c Estimated incidence of fracture per 106 inhabitants of France standardised according to age and gender and divided by 1000. d Incidence of hip fracture estimated per 1000 person-years multiplied by 10. EPIDOS: Epidemiology of Osteoporosis. b
was 12.5 (95% CI: 12.4–12.6) for osteoporotic women aged under 80 years, compared with 2.8 (95% CI: 2.7–2.9) for non-osteoporotic women of the same age. The corresponding figures for women aged 80 years and above were 20.0 (95% CI: 19.9–20.2) and 7.6 (95% CI: 7.5–7.7) for osteoporotic and non-osteoporotic women, respectively [13]. In 1996, Baudoin et al. reviewed data from seven French studies, drawing together subjects from differing regions, age groups, sampling frames, years of study and type of study (retrospective vs. prospective) [6,16]. There was a clear indication of increasing incidence of hip fractures with increasing age; for example, the incidence in women aged 50 years or over was approximately 40 per 10,000 person-years, but was more than 150 per 10,000 personyears in women aged 80 years or over [6]. These data are in agreement with other [5,9]: in Canada, the incidence rate of hip fractures in 2005 was 54.7 per 100,000 person-years for 55–64year-old women, but was of 2636.6 per 100,000 person-years for women over 85 years [9]. Fig. 2 presents fracture incidence rates by age group per 10,000 person-years in women; clearly illustrating how the incidence rate increases with age. Baudoin estimated that the total number of hip fractures in France would increase from 48,000 to over 150,000 by 2050, based on the ageing of the population [16]. The incidence of hip fracture was approximately three times higher in women than in men aged 50 years or over, and more than two times higher in women than in men aged 80 years or over [6]. A similar gender-disparity was observed in hip fracture incidence rates derived from the French National Hospital Database (i.e. one uniform source) [17]. Of almost 73,000 individuals hospitalised for a hip fracture in 2001, the incidence rate for hip fracture was similar between women and men aged 45–65 years, but women aged over 66 years were almost twice as likely to be hospitalised for a hip fracture compared with men of the same age [17].
3.3.2. Vertebral fracture Identification of vertebral fractures is complicated, as there is no consensus definition; it is estimated that only one in three women with vertebral fractures come to medical attention [18,19]. Consequently, the incidence of vertebral fractures is likely to be underestimated [18]. Roux et al. observed 195 osteoporotic menopausal women (aged 65–85 years) who presented to rheumatologists with spine pain over a 6-month period; 50% of these patients were diagnosed with vertebral fracture by radiography [20]. Based on data from the EPIDOS study conducted in France between 1992–1994, Grados et al. estimated the prevalence of radiographically-defined vertebral fractures in women aged over
Fig. 2. Fracture incidence rates per 10,000 person-years in women. Unpublished data from a study by Maravic et al. [17].
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Table 3 Age- and gender-specific vertebral fracture prevalence rates in France (%). Reference
Age class (years)
Grados et al. 2004 [19] Roux et al. 2004 [41]
Men
Women (%)
Note
≥ 75 ≥ 75
22.8 20.3
EPIDOS study. a Grade 1–3: at least 1 fracture EPIDOS study. a Grade 2–3: at least 1 fracture
74 ± 5
23.7
114 women
a
Severity of vertebral fractures graded following Genant et al. [41,42]: grade 1 (mildly deformed): 20 to 25% reduction in anterior, middle and/or posterior height; grade 2 (moderately deformed): 25 to 40% reduction in any height; and grade 3 (severely deformed): 40% reduction in any height.
75 years [18]. Of the 745 French women included in the analysis, 170 had at least one vertebral fracture (22.8%; 95% CI: 19.8–25.8%) (Table 3). Grados et al. hypothesised that if the 5-year prevalence rates observed in their population were applied to the metropolitan French population as it was in the year 2000, an estimated 735,000 French women aged 75 years or over would have one or more vertebral fractures [19]. They further projected that this figure could reach over 1,077,000 by the year 2020 as a result of the ageing of the population [19]. Although an estimated 40,000 to 65,000 new vertebral fractures occur in France each year [21], data are scarce. Data are available at a European level from the European Prospective Osteoporosis Study (EPOS) Group, which recruited men and women aged 50 years and over from population-based registries in 29 European centres [22]. The annual incidence of new vertebral fracture at age 50–79 years across all regions was 1.1% per year for women and 0.6% per year for men. The incidence of morphometric vertebral fractures, defined as a decrease of at least 20% in vertebral height, is shown as a function of age and gender in Table 4; overall, the incidence of vertebral fracture was 10.7 per 1000 person-years in women and 5.7 per 1000 person-years in men. As with hip fractures, incidence increased with age. Differences were also observed in the incidence of vertebral fractures across different European regions, with highest rates reported in Scandinavia (17.7 per 1000 personyears in women and 7.3 per 1000 person-years in men), followed by Western Europe (10.2 per 1000 person-years in women and 6.4 per 1000 person-years in men) (Table 4). 3.3.3. Non-hip/non-vertebral fracture Using reported US wrist fracture rates of 3 per 100 for the 50–59 age group, and 5 per 100 for women aged 60 years and over, Levy estimated that 35,000 cases of wrist fracture occur in France each year in women aged over 50 years [23]. Data from the French National Hospital Database in 1999 was used to evaluate the inci-
Table 4 Incidence of vertebral fractures defined morphometricallya by age, region and gender from the European Prospective Osteoporosis Study (EPOS) Group [22]. Incidence per 1000 person-years Age group (years)
Region
Men
Women
50–54 55–59 60–64 65–69 70–74 75–79 b All ages b All ages b All ages b All ages b All ages
All regions All regions All regions All regions All regions All regions All regions Scandinavia Southern Europe Eastern Europe Western Europe
0.9 5.5 4.8 6.3 8.7 13.6 5.7 7.3 3.6 4.3 6.4
3.6 5.5 9.5 12.3 17.9 29.3 10.7 17.7 10.2 9.2 10.2
a Reduction of at least 20% (+4 mm) in at least one vertebral height and satisfies criteria for prevalent deformities (using McCloskey-Kanis method). b Age standardised to European population.
dence of wrist fracture in French men aged 50 or above [23]. An estimated 23,260 hospital admissions for fracture were attributable to osteoporosis in men, of which 1456 were for distal upper limb fractures. This estimate is likely to be conservative due to the age- and gender-specific attribution probabilities used to estimate osteoporosis-related fractures in this study. More recently, Maravic et al. reported 33,633 individual cases of distal radius and/or ulna fractures in adults aged over 45 years in 2001 [17]. Note that the incidence rates for radius/ulna fractures increased linearly with age and then decreased in the oldest age group (aged 86 years or over; Fig. 2). The incidence of distal radius and/or ulna fractures is higher than that for hip fractures in younger women, but is similar to the incidence of hip fractures in older women. Detailed data on proximal humerus fractures in France are not readily available through literature searches. However, Levy et al. reported that 2,443 fractures of the proximal upper limbs were documented in men aged 50 years and over during 1999 [23]. According to Maravic et al., 12,262 proximal humerus fractures were reported in adults aged over 45 years during 2001 [17]. The incidence of proximal humerus fractures increased gradually with age in both women (Fig. 2) and men [17]. Similarly, data on other limb fractures in France are scarce. Levy et al. documented 1029 fractures of the distal lower limbs in men aged 50 years and over in 1999 [23]. In a pan-European study, Ismail et al. reported incidence rates for “other limb” fractures of between 4 and 8.4 per 1000 person-years in men and women aged 50–79 years, respectively [24]. “Other limb” fractures comprised: hand/carpal bone, femoral shaft, patella, tibia/fibula, ankle and foot, and “not known” (unconfirmed). Unlike the classical osteoporotic fractures of the hip, forearm and proximal humerus, no significant increase in the female-to-male ratio with increasing age was observed with these “other limb” fractures [24].
3.4. Mortality Osteoporotic fractures lead to a high number of excess deaths [25–27]. Most deaths occur within 1 year of fracture, particularly during the first 6 months [3]. Although osteoporotic fractures are less common in men than in women, men experience greater fracture-associated mortality [26]. Center et al. reported that in Australia, excess deaths associated with any major fracture extrapolate to 689 deaths per year among men aged 60–69 years compared with 261 women in the same age range [25]. In France, mortality rates reported for women in the EPIDOS study were 112.4 per 1000 woman-years for women who had sustained a first hip fracture, compared with 27.3 per 1000 personyears for women who did not have any fracture [28]. A higher incidence of mortality in males who have had a fracture has also been observed. In a retrospective study of the Picardy region of France, in-hospital mortality rates for patients hospitalised for hip fracture were 8.1% for women and 10.2% for men [29]. A subsequent prospective study conducted in this region evaluated adults who had sustained hip fracture in the year 1992 [30], at 24 months follow-up, mortality rates had a male-to-female ratio of 1.94 to 1.
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Comorbidity is likely to contribute to mortality [26,27]. Although a proportion of deaths occurring after hip fracture can be attributed to the actual fracture, most are likely to reflect the poor underlying health that leads to both the fracture and ultimate demise [26]. Kado et al. suggested that there are strong links between vertebral fractures and mortality from cancer, particularly lung cancer [27]. Comparing women with and without vertebral factures, those with fractures had a 35% to 40% increase in ageadjusted risk of dying of cancer; the risk of dying of lung cancer was doubled (HR, 2.0; 95% CI, 1.3–2.9). 3.5. Under-reporting of osteoporosis Osteoporosis is significantly under-reported in many countries [18,24,31–33]. Vestergaard et al. concluded that osteoporotic fractures of the hip, spine and forearm are markedly under-diagnosed and under-treated in Denmark [32], and in a French primary care setting, Blotman et al. found that one in two women was diagnosed with osteoporosis after a facture had already occurred [34]. Vertebral fractures in particular may go undetected [18,27]. Delmas et al. reported that the use of ambiguous terminology in radiologists’ reports contributed to false-negative readings in their multinational study, and this is likely to be reflected in the clinical setting [35]. This under-reporting is also reflected in French-specific data. Maravic et al. reported on the number of hospitalisations in the French national database due to rheumatology disorders, which included osteoporosis with or without vertebral fracture coded as a primary diagnosis [36]. The authors expressed surprise at the low number of hospitalisations for vertebral fractures, and concluded that this was either due to poor coding of the primary diagnosis or to the possibility that the majority of patients with vertebral fractures are not admitted to hospital. Baudoin et al. also commented that death certificates underestimate the occurrence of hip fractures in the French population [6]. The widespread under-diagnosis of osteoporosis can result in gross underestimation of the burden of disease on society. 3.6. Geographical and regional variation The incidence of osteoporotic fracture varies from country to country [8,22,26]. Cummings and Melton noted that the risk of fracture in the US was higher in urban than in rural areas [26]. Similarly, two French studies have shown a statistically significant increase in the incidence of hip [6,17], humerus and radius fracture [17] from the west to the east of France. The exceptions to this trend were Brittany, which had a high hip fracture incidence despite being located in the west of France, and the Paris region, which had a low incidence of hip fracture [6]. It was also noted that coastal regions generally had lower hip fracture incidence [6]. 4. Discussion In this report, we have summarised the findings of a literature review of studies published between 1960 and 2009, reporting incidence and prevalence of osteoporosis in France. Worldwide, osteoporosis and osteoporotic fractures pose an increasing burden for healthcare [4] and this picture is reflected in France [17]. The French population in general, and particularly the proportion of the French population aged over 60, is increasing [12]. A pattern of decreasing BMD with increasing age has been observed [13] and the incidence of fracture is high, not only in those classified as osteoporotic but also in the osteopenic population [13,15]. An exponential increase in the incidence of fracture with age has been reported in several French studies [6,17,33], reflecting European
and world trends [5,24]. As in many other countries, French data reveal a gender-disparity in the incidence of osteoporotic fractures, with women showing higher incidence than men [6,17]. Regarding mortality, a significant excess is associated with hip fractures in France [28], and mortality is higher among men than women [8,30]. Recent studies have indicated a decline in rates of hip fractures [5,9]. In the US, Nieves et al. observed a decline in hospital discharge rate for hip fractures between 1996 and 2006 (600 vs. 400 to 100,000), but a stabilisation in those for subtrochanteric, femoral shaft and lower femur fractures (each about 20 per 100,000) [5]. Maravic et al. also reported a stability of peripheral fracture incidence in France between 2002 and 2006 (1580 vs. 1613 wrist and 568 vs. 597 proximal humerus fractures) [37]. Several studies have projected an increase in hip fracture incidence rates due to ageing of the population, even if a reduction in age-specific rate of hip fracture was assumed [9,10]: the number of hip fractures in Scotland was predicted to increase by 45% to 75%, with 45% occurring in patients above 85 years in 2031, compared to 34% in 2004 [10]. The French epidemiological data considered in this review come from a variety of sources. The most recent data available on fracture incidence rates are based on the French National Hospital Database [17]. As the majority of patients with hip fractures are hospitalised, data concerning hip fractures can be considered reliable. Data on forearm fractures in France [17] are consistent with earlier reports that used US incidence rates to estimate the number of fractures in France [21]; although incidence may be underestimated as some forearm fractures will not require hospitalisation [17]. For similar reasons, the incidence rates of other non-hip/nonvertebral fractures are likely to be underestimates [17]. Incidence data for vertebral fractures in France are scarce, and as vertebral fractures are frequently under-diagnosed, incidence is likely to be underestimated [19]. Due to ageing of the global population, an increase in the number of people suffering from fractures is expected over the next few decades unless more effective preventative action is taken [9,34]. A recent French study included 3,097 postmenopausal women diagnosed with osteoporosis who were followed up by general practitioners (GPs) [34]. Fifty percent of the women in this study were first diagnosed with osteoporosis following the occurrence of a fracture. Furthermore, risk factors for osteoporotic fractures, including personal and maternal antecedents and low body mass index, could be identified in almost 70% of patients. These data highlight the potential for improved diagnosis in postmenopausal women; for example, bone densitometry could be used to detect bone loss in patients at risk of osteoporosis, so that bone consolidation treatment can be initiated before a fracture occurs. Recent French public health guidelines recommend BMD screening for all postmenopausal women who have risk factors for osteoporosis [38], and since July 2006 bone densitometry has been reimbursed in France [34]. Our review shows that, as in other countries, osteoporosis is under-diagnosed in France, and that the incidence of fracture will increase in the future. Therefore, we hope that in order to reduce the burden on the healthcare system, these new options for the early diagnosis of patients at risk of future fracture will be adopted in general healthcare practice in France.
Conflicts of interest • Desmond Curran worked as a consultant for Amgen on this project • Milka Maravic worked as a consultant for Amgen on this project • Patrice Fardellone worked as a consultant for Amgen on this project • Valérie Tochon and Philippe Kiefer are Amgen employees
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Acknowledgments This review was funded by Amgen SAS, Paris, France. Amgen (Europe) GmbH provided funding to support editing of the manuscript by Medcept Ltd (Meggen, Switzerland). References [1] EU report on osteoporosis in the European Community – action for prevention. 1998. Accessed on 14 August 2008 from http://www.iofbonehealth. org/publications/eu-policy-report-of-1998.html. [2] WHO Technical Report. Assessment of fracture risk and its application to screening for postmenopausal osteopososis. 1994. Accessed on 14 August 2008 from http://whqlibdoc.who.int/trs/WHO TRS 843.pdf. [3] Keene GS, Parker MJ, Pryor GA. Mortality and morbidity after hip fractures. BMJ 1993;307:1248–50. [4] Johnell O, Kanis JA. An estimate of the worldwide prevalence and disability associated with osteoporotic fractures. Osteoporos Int 2006;17:1726–33. [5] Nieves JW, Bilezikian JP, Lane JM, et al. Fragility fractures of the hip and femur: incidence and patient characteristics. Osteoporos Int 2009. [6] Baudoin C, Fardellone P, Thelot B, et al. Hip fractures in France: the magnitude and perspective of the problem. Osteoporos Int 1996;6(Suppl. 3):1–10. [7] Gullberg B, Johnell O, Kanis JA. World-wide projections for hip fracture. Osteoporos Int 1997;7:407–13. [8] Chapurlat R. Épidémiologie de l’ostéoporose. J Soc Biol 2008;202:251–5. [9] Leslie WD, O’Donnell S, Jean S, et al. Trends in hip fracture rates in Canada. JAMA 2009;302:883–9. [10] Holt G, Smith R, Duncan K, et al. Changes in population demographics and the future incidence of hip fracture. Injury 2009;40:722–6. [11] Brutel C, Omalek L. Projections démographiques pour la France, ses régions et ses départements à l’horizon 2030. Accessed on 31 July 2008 from : http://www.insee.fr/fr/ffc/docs ffc/irsoc016.pdf. [12] Institut nationale de la statistique et des études économiques. Estimation de la population au 1er janvier par région, département, sexe et âge, 1990–2007. 2009. Accessed on 4 June 2009 from http://www.insee. fr/fr/themes/detail.asp?ref id=estim-pop® id=99#p1. [13] Schott AM, Cormier C, Hans D, et al. How hip and whole-body bone mineral density predict hip fracture in elderly women: the EPIDOS Prospective Study. Osteoporos Int 1998;8:247–54. [14] Robbins JA, Schott AM, Garnero P, et al. Risk factors for hip fracture in women with high BMD: EPIDOS study. Osteoporos Int 2005;16:149–54. [15] Sornay-Rendu E, Munoz F, Garnero P, et al. Identification of osteopenic women at high risk of fracture: the OFELY study. J Bone Miner Res 2005;20:1813–9. [16] Baudoin C. The cost of osteoporosis in France. Rev Rhum Engl Ed 1997;64:441–2. [17] Maravic M, Le Bihan C, Landais P, et al. Incidence and cost of osteoporotic fractures in France during 2001. A methodological approach by the national hospital database. Osteoporos Int 2005;16:1475–80. [18] Cooper C, Atkinson EJ, O’Fallon WM, et al. Incidence of clinically diagnosed vertebral fractures: a population-based study in Rochester, Minnesota, 1985–1989. J Bone Miner Res 1992;7:221–7. [19] Grados F, Marcelli C, Dargent-Molina P, et al. Prevalence of vertebral fractures in French women older than 75 years from the EPIDOS study. Bone 2004;34:362–7. [20] Roux C, Reygrobellet C, Audran M. Étude médicoéconomique de la fracture vertébrale diagnostiquée en rhumatologie. Communications orales en sessions parallèles. Rev Rhum 2004;71:903–4.
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Review
Epidemiology of osteoporosis-related fractures in France: A literature review Desmond Curran a , Milka Maravic b,∗ , Philippe Kiefer c , Valérie Tochon c , Patrice Fardellone d a
Omega Research, 189, Shanliss Road, Santry, Dublin 9, Ireland Département d’information médicale, hôpital Léopold-Bellan, 19–21, rue Vercingétorix, 75674 Paris cedex 14, France c AMGEN France, 62, boulevard Victor-Hugo, 92523 Neuilly-sur-Seine cedex France d Rheumatology Department, University Hospital Amiens, place Victor-Pauchet, 80054 Amiens cedex 1, France b
a r t i c l e
i n f o
Article history: Accepted 3 February 2010 Available online 7 April 2010 Keywords: Osteoporosis Fracture France Epidemiology Postmenopausal
a b s t r a c t Objectives: To evaluate the health implications and economic burden on society of osteoporotic fractures as a major source of morbidity and mortality in the ageing population. Methods: We have summarised the findings of a literature review of French studies published between 1960 and 2009, characterised the epidemiology of osteoporosis and osteoporotic fractures, and predicted future trends. Results: Published data for France supported the observation that osteoporosis is under-diagnosed in many countries. The incidence of fracture increased exponentially with age, alongside a concurrent decrease in bone mineral density, a risk factor for fracture. Combined with a projected rise in the French elderly population, this poses a significant burden for the future. The incidence of fracture was high in the osteopenic population; consequently, fragility fractures may be underestimated if reports focus on osteoporotic women only. As in many other countries, French data revealed that women have a higher incidence of osteoporotic fractures than men, although mortality from hip fracture was higher in men. Discussion: Due to ageing of the population, an increase in the number of people suffering from fractures is predicted over the next few decades unless preventative action is taken, highlighting the need for improved diagnosis and screening in postmenopausal women. © 2010 Société franc¸aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved.
1. Introduction Osteoporotic fractures are a major source of morbidity and mortality in the ageing population and place a significant health and economic burden on society [1]. Osteoporosis is a systemic skeletal disease characterised by low bone mass and micro-architectural deterioration, with a consequent increase in bone fragility and susceptibility to fracture [1]. In 1994, a World Health Organisation (WHO) expert panel defined diagnostic criteria for osteoporosis on the basis of the measurement of bone mineral density (BMD) [2]. The most important cause of osteoporosis is the gradual bone loss that occurs after the menopause [2]. Clinically, osteoporosis is often first recognised by the occurrence of low-trauma fractures; the three most frequent are vertebral, distal forearm and hip fractures [1]. Fractures are associated with increased mortality and often result in significant morbidity, impacting on quality of life. Hip fractures are particularly serious; in a prospective study of 1000 consecutive admissions for hip fracture in Britain (average
∗ Corresponding author. Phone: 33 1 40 48 68 34; Fax: 33 1 40 48 68 34. E-mail addresses: [email protected] (D. Curran), [email protected] (M. Maravic), [email protected] (P. Kiefer), [email protected] (V. Tochon), [email protected] (P. Fardellone).
age 79), mortality at 12 months was 33% and 15% of patients died without being discharged from hospital [3]. It is estimated that 60% of the global burden of osteoporosis is accounted for by non-hip fractures [4]. The incidence of osteoporosis-related fractures rises steeply with increasing age, with hip fracture incidence rates increasing exponentially [5]. Similarly, there is a strong association with gender: the female-to-male ratio of hip fracture is greater than 2:1 in people over 50 years of age [6]. The worldwide health and economic burden of osteoporosis is likely to increase in the future, as improvements in life expectancy will lead to a growing population of elderly people with a high risk of fracture [4,7]. In the EU, the population of people aged more than 65 years in 15 member states is predicted to increase from 58 million in 1995 to 108 million in 2040 [1]. In particular, the population aged more than 80 years, in whom the incidence of osteoporotic fracture is greatest, will grow from 8.9 million women and 4.5 million men in 1995 to 26.4 million women and 17.4 million men in 2050 [1]. A concurrent decline in the population of working age during this time, predicted to decrease from 234 million in 2010 to 172 million in 2050, will lead to a disproportionate increase in the burden of osteoporosis to society [1]. Recent studies have shown that age-specific rates of osteoporosis fractures might be declining or stabilising [5,8,9]; however, due
1297-319X/$ – see front matter © 2010 Société franc¸aise de rhumatologie. Published by Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2010.02.006
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to ageing of the population, the absolute number of fractures is still expected to increase [8–10]. In the EU, the number of hip fractures occurring each year is expected to increase by 135% over the next 50 years from 414,000 to 972,000, and the number of vertebral fractures is predicted to increase by 57%, rising from 23.7 million in the year 2000 to 37.3 million in 2050 [1]. Since these calculations were not adjusted for secular trends, they are likely to underestimate the true increase in fractures [1,7]. This literature review focused on osteoporosis in postmenopausal women in France, with the aim of drawing together information about the epidemiology of osteoporosis and osteoporotic fractures in France and projecting future trends. 2. Literature search The search focused on epidemiology. The epidemiological endpoints of interest were: current and projected demographic trends in France, incidence and prevalence of low BMD, incidence and prevalence of osteoporotic fracture, and incidence of mortality. Information on the under-reporting of osteoporosis and on regional variations within France was also reviewed. Medline was searched from 1960 to 2009 using combinations of the following keywords (in French and English): osteoporosis, fracture, cost, economic impact, menopause, postmenopausal, epidemiology and country (e.g. France or French). The terms country and osteoporosis or fracture were included in all searches (e.g. France, fracture, cost). Searches of conference abstract books and multiple web searches were performed using the same keywords. Titles and abstracts were reviewed to decide whether an article/text should be examined further. Reports were reviewed if they provided details on: (i) incidence or prevalence of fractures (or osteoporosis) and/or subsequent trends; (ii) resource use (e.g. hospital stay, specialist and general practitioner [GP] visits, drugs, transport) and/or associated costs; (iii) patient-reported outcomes, follow-up or mortality of patients. Furthermore, papers referenced in these publications were retrieved if they were thought to substantially contribute to that publication and provide additional information. A report summarising the findings of the review was circulated to French experts in the field of osteoporosis to check for completeness and accuracy. 3. Results 3.1. French demographic trends Over the past 30 years, the population of mainland France has grown from 50.5 million inhabitants in 1970 to 58.5 million in 2000 [11] and to 61.8 million in 2007 (Table 1) [12]. In particular, the number of people aged 60 years and above (i.e. at high risk of osteoporosis-related fractures) is increasing. The population aged over 60 rose from 9.1 to 12.1 million between 1970 and 2000, and is projected to rise to between 19.5 and 20.4 million by 2030 as the baby-boom generation ages [11]. This means that by 2030 one person in three will be aged 60 years or over, compared with one in five in 2000. The number of people aged over 75 will effectively double between 2000 and 2030; increasing from 4.2 to 8.3 million [11]. Table 1 The French mainlanda population by age and sex in 2007 [12]. Age group (years)
Men (N)
Women (N)
Total (N)
0–59 60–74 ≥ 75
24,244,193 3,753,201 1,903,199
24,259,207 4,282,239 3,328,961
48,503,400 8,035,440 5,232,160
Total
29,900,593
31,870,407
61,771 000
a
Includes Corsica, excludes overseas regions and territories.
Fig. 1. Average bone mineral density by age group for 7598 women from the Epidemiology of Osteoporosis (EPIDOS) Study [13].
Overall, the population of mainland France is expected to increase to 64.5 million in 2040 [11]. 3.2. Bone mineral density evolution Low BMD has been shown to be a risk factor for fracture [2]. Using data from the Epidemiology of Osteoporosis (EPIDOS) prospective study, Schott et al. demonstrated a decrease in BMD in association with increasing age in a cohort of 7598 women aged 75 or over in five French cities (Fig. 1) [13]. The hip fracture risk increased 1.6 times (95% CI: 1.2–2.0) for each S.D. decrease in whole-body BMD. According to WHO definitions, only 6.5% of the women who participated in the EPIDOS study were considered to have normal bone mass, 46% were considered to have osteopenia and 48% were diagnosed as osteoporotic [13]. Although the incidence of hip fracture is high in osteoporotic women, many hip fractures occur in women whose BMD is above a T-score of −2.5 S.D. [14,15]. In the EPIDOS cohort, the incidence of hip fracture per 1000 woman-years was highest in osteoporotic women (16.4; 95% CI: 16.4–16.5), but was also greater in osteopenic women (5.4; 95% CI: 5.3–5.5) than in women with normal BMD (1.1, 95% CI: 1.0–1.2) [13]. A significant risk of fracture in the osteopenic population was also demonstrated in a large population-based cohort (os des femmes de Lyon [OFELY]) of 671 postmenopausal women followed for a median of 9.1 years [15]. In this study, all peripheral fractures were confirmed radiographically and vertebral fractures were identified by the Genant method. Forty-four percent of incident fractures occurred in osteoporotic women, 48% in osteopenic women and 8% in women with normal BMD, in a population where 21% were osteoporotic, 48% were osteopenic and 31% had normal BMD. The overall incidence of fracture in this study was 19 per 1000 woman-years [15]. Given the risk of fracture in the osteopenic population, fragility fractures may be underestimated if reports focus on osteoporotic women only [15]. 3.3. Age- and gender-specific incidence/prevalence of fractures 3.3.1. Hip fracture Data from several French studies show that the incidence of hip fracture is higher in women with osteoporosis, increases exponentially with age, and is higher in females than males (Table 2). In the EPIDOS cohort, the incidence of hip fracture per 1000 woman-years
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Table 2 Age- and gender-specific hip fracture incidence rates in France (per 10,000 person-years). Study
Age class (years)
a
Schott et al. 1998 [13]
75–80
b
Baudoin et al. 1996 [6]
Men
> 80
b
c
Baudoin et al. 1996 [6]
Maravic et al. 2005 [17]
d
Blachier 1999 [39]
Note
125
EPIDOS study
200
≥ 20
5.8
16.8
Surveys 2–7
≥ 50 ≥ 50 ≥ 65 ≥ 65 ≥ 65
13.4 13.6 26.2 27.8 27.8
37.6 42.6 67.9 77.9 76.1
Surveys 2–7 Death certificates Surveys 2–7 Death certificates Survey 1
≥ 20
5.8
16.8
Surveys 2–7
≥ 60 ≥ 80
19.7 71.2
53.4 154.9
Surveys 2–7 Surveys 2–7
46–65
3.8
3.7
66–80 ≥ 81
19.0 125.6
38.4 258.5
60
French National Hospital Database
50
> 80 Ribot et al. 1990 [40]
Women
150
> 50
5.1
21.3
Toulouse
> 50
4.9
23.8
Île-de-France
a
Incidence for a subset of 3043 women from the EPIDOS study classified as osteoporotic; estimated per 1000 woman-years and multiplied by 10. Survey 1 includes national data collected in France between 1978–1982; Surveys 2–7 include data collected from six surveys carried out in five different regions of France between 1986–1992; Incidence of hip fractures declared on death certificates. c Estimated incidence of fracture per 106 inhabitants of France standardised according to age and gender and divided by 1000. d Incidence of hip fracture estimated per 1000 person-years multiplied by 10. EPIDOS: Epidemiology of Osteoporosis. b
was 12.5 (95% CI: 12.4–12.6) for osteoporotic women aged under 80 years, compared with 2.8 (95% CI: 2.7–2.9) for non-osteoporotic women of the same age. The corresponding figures for women aged 80 years and above were 20.0 (95% CI: 19.9–20.2) and 7.6 (95% CI: 7.5–7.7) for osteoporotic and non-osteoporotic women, respectively [13]. In 1996, Baudoin et al. reviewed data from seven French studies, drawing together subjects from differing regions, age groups, sampling frames, years of study and type of study (retrospective vs. prospective) [6,16]. There was a clear indication of increasing incidence of hip fractures with increasing age; for example, the incidence in women aged 50 years or over was approximately 40 per 10,000 person-years, but was more than 150 per 10,000 personyears in women aged 80 years or over [6]. These data are in agreement with other [5,9]: in Canada, the incidence rate of hip fractures in 2005 was 54.7 per 100,000 person-years for 55–64year-old women, but was of 2636.6 per 100,000 person-years for women over 85 years [9]. Fig. 2 presents fracture incidence rates by age group per 10,000 person-years in women; clearly illustrating how the incidence rate increases with age. Baudoin estimated that the total number of hip fractures in France would increase from 48,000 to over 150,000 by 2050, based on the ageing of the population [16]. The incidence of hip fracture was approximately three times higher in women than in men aged 50 years or over, and more than two times higher in women than in men aged 80 years or over [6]. A similar gender-disparity was observed in hip fracture incidence rates derived from the French National Hospital Database (i.e. one uniform source) [17]. Of almost 73,000 individuals hospitalised for a hip fracture in 2001, the incidence rate for hip fracture was similar between women and men aged 45–65 years, but women aged over 66 years were almost twice as likely to be hospitalised for a hip fracture compared with men of the same age [17].
3.3.2. Vertebral fracture Identification of vertebral fractures is complicated, as there is no consensus definition; it is estimated that only one in three women with vertebral fractures come to medical attention [18,19]. Consequently, the incidence of vertebral fractures is likely to be underestimated [18]. Roux et al. observed 195 osteoporotic menopausal women (aged 65–85 years) who presented to rheumatologists with spine pain over a 6-month period; 50% of these patients were diagnosed with vertebral fracture by radiography [20]. Based on data from the EPIDOS study conducted in France between 1992–1994, Grados et al. estimated the prevalence of radiographically-defined vertebral fractures in women aged over
Fig. 2. Fracture incidence rates per 10,000 person-years in women. Unpublished data from a study by Maravic et al. [17].
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Table 3 Age- and gender-specific vertebral fracture prevalence rates in France (%). Reference
Age class (years)
Grados et al. 2004 [19] Roux et al. 2004 [41]
Men
Women (%)
Note
≥ 75 ≥ 75
22.8 20.3
EPIDOS study. a Grade 1–3: at least 1 fracture EPIDOS study. a Grade 2–3: at least 1 fracture
74 ± 5
23.7
114 women
a
Severity of vertebral fractures graded following Genant et al. [41,42]: grade 1 (mildly deformed): 20 to 25% reduction in anterior, middle and/or posterior height; grade 2 (moderately deformed): 25 to 40% reduction in any height; and grade 3 (severely deformed): 40% reduction in any height.
75 years [18]. Of the 745 French women included in the analysis, 170 had at least one vertebral fracture (22.8%; 95% CI: 19.8–25.8%) (Table 3). Grados et al. hypothesised that if the 5-year prevalence rates observed in their population were applied to the metropolitan French population as it was in the year 2000, an estimated 735,000 French women aged 75 years or over would have one or more vertebral fractures [19]. They further projected that this figure could reach over 1,077,000 by the year 2020 as a result of the ageing of the population [19]. Although an estimated 40,000 to 65,000 new vertebral fractures occur in France each year [21], data are scarce. Data are available at a European level from the European Prospective Osteoporosis Study (EPOS) Group, which recruited men and women aged 50 years and over from population-based registries in 29 European centres [22]. The annual incidence of new vertebral fracture at age 50–79 years across all regions was 1.1% per year for women and 0.6% per year for men. The incidence of morphometric vertebral fractures, defined as a decrease of at least 20% in vertebral height, is shown as a function of age and gender in Table 4; overall, the incidence of vertebral fracture was 10.7 per 1000 person-years in women and 5.7 per 1000 person-years in men. As with hip fractures, incidence increased with age. Differences were also observed in the incidence of vertebral fractures across different European regions, with highest rates reported in Scandinavia (17.7 per 1000 personyears in women and 7.3 per 1000 person-years in men), followed by Western Europe (10.2 per 1000 person-years in women and 6.4 per 1000 person-years in men) (Table 4). 3.3.3. Non-hip/non-vertebral fracture Using reported US wrist fracture rates of 3 per 100 for the 50–59 age group, and 5 per 100 for women aged 60 years and over, Levy estimated that 35,000 cases of wrist fracture occur in France each year in women aged over 50 years [23]. Data from the French National Hospital Database in 1999 was used to evaluate the inci-
Table 4 Incidence of vertebral fractures defined morphometricallya by age, region and gender from the European Prospective Osteoporosis Study (EPOS) Group [22]. Incidence per 1000 person-years Age group (years)
Region
Men
Women
50–54 55–59 60–64 65–69 70–74 75–79 b All ages b All ages b All ages b All ages b All ages
All regions All regions All regions All regions All regions All regions All regions Scandinavia Southern Europe Eastern Europe Western Europe
0.9 5.5 4.8 6.3 8.7 13.6 5.7 7.3 3.6 4.3 6.4
3.6 5.5 9.5 12.3 17.9 29.3 10.7 17.7 10.2 9.2 10.2
a Reduction of at least 20% (+4 mm) in at least one vertebral height and satisfies criteria for prevalent deformities (using McCloskey-Kanis method). b Age standardised to European population.
dence of wrist fracture in French men aged 50 or above [23]. An estimated 23,260 hospital admissions for fracture were attributable to osteoporosis in men, of which 1456 were for distal upper limb fractures. This estimate is likely to be conservative due to the age- and gender-specific attribution probabilities used to estimate osteoporosis-related fractures in this study. More recently, Maravic et al. reported 33,633 individual cases of distal radius and/or ulna fractures in adults aged over 45 years in 2001 [17]. Note that the incidence rates for radius/ulna fractures increased linearly with age and then decreased in the oldest age group (aged 86 years or over; Fig. 2). The incidence of distal radius and/or ulna fractures is higher than that for hip fractures in younger women, but is similar to the incidence of hip fractures in older women. Detailed data on proximal humerus fractures in France are not readily available through literature searches. However, Levy et al. reported that 2,443 fractures of the proximal upper limbs were documented in men aged 50 years and over during 1999 [23]. According to Maravic et al., 12,262 proximal humerus fractures were reported in adults aged over 45 years during 2001 [17]. The incidence of proximal humerus fractures increased gradually with age in both women (Fig. 2) and men [17]. Similarly, data on other limb fractures in France are scarce. Levy et al. documented 1029 fractures of the distal lower limbs in men aged 50 years and over in 1999 [23]. In a pan-European study, Ismail et al. reported incidence rates for “other limb” fractures of between 4 and 8.4 per 1000 person-years in men and women aged 50–79 years, respectively [24]. “Other limb” fractures comprised: hand/carpal bone, femoral shaft, patella, tibia/fibula, ankle and foot, and “not known” (unconfirmed). Unlike the classical osteoporotic fractures of the hip, forearm and proximal humerus, no significant increase in the female-to-male ratio with increasing age was observed with these “other limb” fractures [24].
3.4. Mortality Osteoporotic fractures lead to a high number of excess deaths [25–27]. Most deaths occur within 1 year of fracture, particularly during the first 6 months [3]. Although osteoporotic fractures are less common in men than in women, men experience greater fracture-associated mortality [26]. Center et al. reported that in Australia, excess deaths associated with any major fracture extrapolate to 689 deaths per year among men aged 60–69 years compared with 261 women in the same age range [25]. In France, mortality rates reported for women in the EPIDOS study were 112.4 per 1000 woman-years for women who had sustained a first hip fracture, compared with 27.3 per 1000 personyears for women who did not have any fracture [28]. A higher incidence of mortality in males who have had a fracture has also been observed. In a retrospective study of the Picardy region of France, in-hospital mortality rates for patients hospitalised for hip fracture were 8.1% for women and 10.2% for men [29]. A subsequent prospective study conducted in this region evaluated adults who had sustained hip fracture in the year 1992 [30], at 24 months follow-up, mortality rates had a male-to-female ratio of 1.94 to 1.
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Comorbidity is likely to contribute to mortality [26,27]. Although a proportion of deaths occurring after hip fracture can be attributed to the actual fracture, most are likely to reflect the poor underlying health that leads to both the fracture and ultimate demise [26]. Kado et al. suggested that there are strong links between vertebral fractures and mortality from cancer, particularly lung cancer [27]. Comparing women with and without vertebral factures, those with fractures had a 35% to 40% increase in ageadjusted risk of dying of cancer; the risk of dying of lung cancer was doubled (HR, 2.0; 95% CI, 1.3–2.9). 3.5. Under-reporting of osteoporosis Osteoporosis is significantly under-reported in many countries [18,24,31–33]. Vestergaard et al. concluded that osteoporotic fractures of the hip, spine and forearm are markedly under-diagnosed and under-treated in Denmark [32], and in a French primary care setting, Blotman et al. found that one in two women was diagnosed with osteoporosis after a facture had already occurred [34]. Vertebral fractures in particular may go undetected [18,27]. Delmas et al. reported that the use of ambiguous terminology in radiologists’ reports contributed to false-negative readings in their multinational study, and this is likely to be reflected in the clinical setting [35]. This under-reporting is also reflected in French-specific data. Maravic et al. reported on the number of hospitalisations in the French national database due to rheumatology disorders, which included osteoporosis with or without vertebral fracture coded as a primary diagnosis [36]. The authors expressed surprise at the low number of hospitalisations for vertebral fractures, and concluded that this was either due to poor coding of the primary diagnosis or to the possibility that the majority of patients with vertebral fractures are not admitted to hospital. Baudoin et al. also commented that death certificates underestimate the occurrence of hip fractures in the French population [6]. The widespread under-diagnosis of osteoporosis can result in gross underestimation of the burden of disease on society. 3.6. Geographical and regional variation The incidence of osteoporotic fracture varies from country to country [8,22,26]. Cummings and Melton noted that the risk of fracture in the US was higher in urban than in rural areas [26]. Similarly, two French studies have shown a statistically significant increase in the incidence of hip [6,17], humerus and radius fracture [17] from the west to the east of France. The exceptions to this trend were Brittany, which had a high hip fracture incidence despite being located in the west of France, and the Paris region, which had a low incidence of hip fracture [6]. It was also noted that coastal regions generally had lower hip fracture incidence [6]. 4. Discussion In this report, we have summarised the findings of a literature review of studies published between 1960 and 2009, reporting incidence and prevalence of osteoporosis in France. Worldwide, osteoporosis and osteoporotic fractures pose an increasing burden for healthcare [4] and this picture is reflected in France [17]. The French population in general, and particularly the proportion of the French population aged over 60, is increasing [12]. A pattern of decreasing BMD with increasing age has been observed [13] and the incidence of fracture is high, not only in those classified as osteoporotic but also in the osteopenic population [13,15]. An exponential increase in the incidence of fracture with age has been reported in several French studies [6,17,33], reflecting European
and world trends [5,24]. As in many other countries, French data reveal a gender-disparity in the incidence of osteoporotic fractures, with women showing higher incidence than men [6,17]. Regarding mortality, a significant excess is associated with hip fractures in France [28], and mortality is higher among men than women [8,30]. Recent studies have indicated a decline in rates of hip fractures [5,9]. In the US, Nieves et al. observed a decline in hospital discharge rate for hip fractures between 1996 and 2006 (600 vs. 400 to 100,000), but a stabilisation in those for subtrochanteric, femoral shaft and lower femur fractures (each about 20 per 100,000) [5]. Maravic et al. also reported a stability of peripheral fracture incidence in France between 2002 and 2006 (1580 vs. 1613 wrist and 568 vs. 597 proximal humerus fractures) [37]. Several studies have projected an increase in hip fracture incidence rates due to ageing of the population, even if a reduction in age-specific rate of hip fracture was assumed [9,10]: the number of hip fractures in Scotland was predicted to increase by 45% to 75%, with 45% occurring in patients above 85 years in 2031, compared to 34% in 2004 [10]. The French epidemiological data considered in this review come from a variety of sources. The most recent data available on fracture incidence rates are based on the French National Hospital Database [17]. As the majority of patients with hip fractures are hospitalised, data concerning hip fractures can be considered reliable. Data on forearm fractures in France [17] are consistent with earlier reports that used US incidence rates to estimate the number of fractures in France [21]; although incidence may be underestimated as some forearm fractures will not require hospitalisation [17]. For similar reasons, the incidence rates of other non-hip/nonvertebral fractures are likely to be underestimates [17]. Incidence data for vertebral fractures in France are scarce, and as vertebral fractures are frequently under-diagnosed, incidence is likely to be underestimated [19]. Due to ageing of the global population, an increase in the number of people suffering from fractures is expected over the next few decades unless more effective preventative action is taken [9,34]. A recent French study included 3,097 postmenopausal women diagnosed with osteoporosis who were followed up by general practitioners (GPs) [34]. Fifty percent of the women in this study were first diagnosed with osteoporosis following the occurrence of a fracture. Furthermore, risk factors for osteoporotic fractures, including personal and maternal antecedents and low body mass index, could be identified in almost 70% of patients. These data highlight the potential for improved diagnosis in postmenopausal women; for example, bone densitometry could be used to detect bone loss in patients at risk of osteoporosis, so that bone consolidation treatment can be initiated before a fracture occurs. Recent French public health guidelines recommend BMD screening for all postmenopausal women who have risk factors for osteoporosis [38], and since July 2006 bone densitometry has been reimbursed in France [34]. Our review shows that, as in other countries, osteoporosis is under-diagnosed in France, and that the incidence of fracture will increase in the future. Therefore, we hope that in order to reduce the burden on the healthcare system, these new options for the early diagnosis of patients at risk of future fracture will be adopted in general healthcare practice in France.
Conflicts of interest • Desmond Curran worked as a consultant for Amgen on this project • Milka Maravic worked as a consultant for Amgen on this project • Patrice Fardellone worked as a consultant for Amgen on this project • Valérie Tochon and Philippe Kiefer are Amgen employees
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