Osteoporosis International

, Volume 23, Issue 3, pp 1061–1068

Undertreatment of osteoporosis in persons with dementia? A population-based study

Authors

    • Aging Research Center, Department of Neurobiology, Care Sciences and SocietyKarolinska Institutet and Stockholm University
    • Stockholm Gerontology Research Center
  • J. Fastbom
    • Aging Research Center, Department of Neurobiology, Care Sciences and SocietyKarolinska Institutet and Stockholm University
    • Stockholm Gerontology Research Center
  • L. Fratiglioni
    • Aging Research Center, Department of Neurobiology, Care Sciences and SocietyKarolinska Institutet and Stockholm University
    • Stockholm Gerontology Research Center
  • K. Johnell
    • Aging Research Center, Department of Neurobiology, Care Sciences and SocietyKarolinska Institutet and Stockholm University
    • Stockholm Gerontology Research Center
Original Article

DOI: 10.1007/s00198-011-1636-8

Cite this article as:
Haasum, Y., Fastbom, J., Fratiglioni, L. et al. Osteoporos Int (2012) 23: 1061. doi:10.1007/s00198-011-1636-8

Abstract

Summary

In this population-based study of more than 2,600 elderly, people with dementia received less preventive treatment for osteoporosis compared to people without dementia, although osteoporotic fractures were more common in patients with dementia. Thus, our results indicate an undertreatment of osteoporosis in dementia.

Introduction

This study compares the use of osteoporosis drugs in elderly with and without dementia, taking into account osteoporotic fractures and type of housing.

Methods

We analyzed data from the baseline examination (2001–2004) of The Swedish National Study on Aging and Care- Kungsholmen (SNAC-K), Stockholm, Sweden. Participants were aged ≥66 years (n = 2610). We analysed the use of bisphosphonates, raloxifene, and calcium/vitamin D combinations in relation to clinically based dementia diagnosis. Information about osteoporotic fractures during the previous 4 years was obtained from the Swedish National Patient Register. We used logistic regression to analyze the association between dementia status and use of osteoporosis drugs.

Results

Osteoporosis drugs (mainly calcium/vitamin D combinations) were used by 5% of the persons with dementia and 12% of the persons without dementia. Furthermore, 25% of the persons with dementia and 7% of the persons without dementia had had at least one osteoporotic fracture during the past 4 years. After controlling for age, sex, osteoporotic fractures, and type of housing (own home or institution), persons with dementia were less likely to use osteoporosis drugs than persons without dementia (OR = 0.34; 95% CI, 0.19–0.59).

Conclusions

Our results indicate an undertreatment of osteoporosis in persons with dementia, although osteoporotic fractures are common among these patients.

Keywords

Community dwellingDementiaInstitutionOsteoporosisThe Swedish National Study on Aging and Care-Kungsholmen

Introduction

Osteoporosis is a common problem in the elderly population. Sweden has one of the highest prevalences of osteoporosis in the world [1], and the total number of fractures caused by osteoporosis has been estimated to 70,000 per year in Sweden [2]. Kanis et al. [3] have defined osteoporotic fractures as fractures “associated with low bone mineral density (BMD) and those that increase in incidence with age after the age of 50 years.” Osteoporotic fractures are an economical burden for society and affect the individual in terms of immobility and decreased quality of life [4]. Hip fractures, a severe consequence of osteoporosis, have been associated with increased morbidity and mortality [1, 5]. In nursing homes, where the frailest elderly reside, the prevalence of osteoporosis has been estimated to approximately 50% among men and up to 85% among women [6, 7].

Several types of drugs are available for treatment of osteoporosis and prevention of osteoporotic fractures in the elderly [2, 811]. Calcium and vitamin D supplements may reduce the risk for hip and other non-spinal fractures in the elderly [2]. Bisphosphonates have been shown to prevent vertebral and peripheral fractures in postmenopausal women [2, 12, 13] and hip fractures in elderly women [14]. These drugs have been less well-studied in elderly men, but may reduce the risk of vertebral fractures among men [15] and increase bone mineral density and prevent hip fractures in elderly men after stroke [9]. However, previous studies have reported a low use of osteoporosis drugs in the oldest old [16], in nursing homes [17], and for prevention of secondary osteoporotic fractures [1820].

Osteoporosis often co-occurs with dementia, as both disorders are strongly related to old age [21]. Dementia has been associated with an increased risk of falls and hip fractures [21, 22], suggesting that people with dementia are a risk population for osteoporotic fractures [2]. In Sweden, more than 140,000 persons have a dementia disorder, and 60% of the residents in institutions have dementia [23]. However, few studies have investigated the use of osteoporosis drugs in people with dementia. Therefore, the aim of the present study was to compare the use of osteoporosis drugs in elderly with and without dementia, taking into account osteoporotic fractures and type of housing.

Methods

Study population

The Swedish National Study on Aging and Care (SNAC) is a national longitudinal multi-purpose study consisting of four research centers in different geographical areas of Sweden. This study is based on baseline data from one of these centers, the population based part of the Swedish National Study on Aging and Care-Kungsholmen (SNAC-K). The design of the study has been described elsewhere [24]. Briefly, SNAC-K is an ongoing longitudinal study of aging and health. It consists of a random sample of older persons from different age cohorts (age 60, 66, 72, 78, 81, 84, 87, 90, 93, 96, and 99 years and older), living in Kungsholmen/Essingeöarna, a central part of Stockholm. At baseline (2001–2004), each participant met a physician, a registered nurse, and a psychologist for interviews and examination (the protocol is available at http://www.snac.org). The clinical examination included recording of medical history, geriatric examination, physical and cognitive testing, and laboratory tests. Inclusion criteria were a registered address in Kungsholmen/Essingeöarna in Stockholm at time of birthday for the ages specified above. Both persons living in their own homes and in institutions were invited to participate. Persons with deafness or without knowledge of the Swedish language could, in most cases, not participate. Informed consent was obtained for each participant. If the participant was unable to make an informed decision, a proxy consent was requested from a close relative.

Of the 4,790 invited subjects, 1,227 refused to participate and 200 died before the examination. Sixty-five percent of the participants were women, compared to 67% among the non-participants (p =0.19). The mean age was 74 years for participants compared to 77 years among non-participants (p < 0.001). In total, 3,353 subjects agreed and completed the interview and examination at baseline. The response rate, corrected for non-response due to death before examination, was 73%. In this study, only subjects aged 66 years and older with complete drug data (only five persons had missing information about drug use) were included (n = 2610).

Definitions

Information about drug use was collected by a physician during the clinical examination. Before the interview, participants were instructed to bring a list of currently used drugs, including both regularly and as needed used drugs. Drug prescriptions and medical containers were inspected when available (for instance when the interview was carried out in the participant’s own home). Both prescribed and over-the-counter drugs were recorded. When the older person could not provide information (e.g., due to cognitive impairment), a relative or a close informant was asked instead. If the person was living in an old people’s home, group dwelling, nursing home, or, in some cases, sheltered accommodation, the information about drug use was collected directly from medical records.

Drugs were classified according to the Anatomical Therapeutic Chemical (ATC) Classification system, as recommended by the World Health Organization [25]. We analysed the use of the following osteoporosis drugs: calcium/vitamin D combinations (ATC code A12AX), raloxifene (G03XC01), and bisphosphonates (M05BA and M05BB). We also analyzed the use of “any osteoporosis drug,” which refers to the use of at least one drug in the ATC-classes A12AX, G03XC01, M05BA, or M05BB. In addition, we analyzed the use of calcium alone (ATC code A12AA), considered to be insufficient osteoporosis treatment [2]. Only drugs that were currently used at the time of the baseline examination were analyzed in this study.

Fractures that occurred within a 4-year period before the baseline examination were analyzed. Information about osteoporotic fractures was obtained from the Swedish National Patient Register, which covers all hospitals in Sweden [26]. We included the following fractures (with ICD10 codes), commonly related to osteoporosis [27, 28]: fractures of femur (S72), rib(s), sternum and thoracic spine (S22), lumbar spine and pelvis (S32), shoulder and upper arm (S42), forearm (S52), and lower leg, including ankle (S82). We also analyzed the occurrence of “any osteoporotic fracture,” defined as at least one of the above-mentioned fractures.

Dementia was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (4th Edition) criteria [29]. It includes deficiencies in several cognitive functions, including memory impairment and at least one of the following disturbances: aphasia, apraxia, agnosia, or disturbance of executive functioning. The diagnosis was set in a three step procedure. Two physicians set the diagnosis independently of each other. In case of disagreement, a third expert was consulted to make the final diagnosis [30]. In total, 238 dementia cases were identified in ages 66 years and older in this study. In addition, 67 persons were diagnosed as having questionable dementia, when memory impairment was present while a second cognitive dysfunction was questionable. In the current study, these persons were included in the dementia group [31].

The type of housing variable was categorized into own home (i.e., rented or owned) or institution (i.e., sheltered accommodation, old people’s home, group dwelling, or nursing home) [32].

The study was approved by the ethical board in Stockholm (Dnr 01–114).

Statistical analysis

As the sampling fractions in the different age groups were different, data from the examined population were weighted against the total population in Kungsholmen/Essingeöarna, by age group and sex.

We used logistic regression to analyze the association between dementia status and use of osteoporosis drugs. We used both crude and adjusted analysis. First, we analyzed the whole dataset (n = 2610). In model 1, adjustment was made for age (continuous variable) and sex. In model 2, additional adjustment was made for type of housing (own home or institution) and osteoporotic fractures. There was no interaction between dementia status and type of housing. Second, we excluded the severely demented cases, in order to investigate if our results were influenced by the low use of osteoporosis drugs in patients with severe dementia. We used the Mini Mental State Examination (MMSE) [33] as a measure of dementia severity and included only subjects with MMSE ≥ 10 (n = 2,493) in this sub-group analysis. The MMSE is a screening test for cognitive function. The score ranges from 0 to 30, with a higher score indicating better cognitive function.Third, we analyzed the persons with and without dementia separately to study whether the explanatory variables were differently associated with use osteoporosis drugs in the two groups. Finally, in order to analyze if the association between dementia status and use of osteoporosis drugs differed between ages, we made separate analyzes of people aged <80 and ≥80 years.

The results are presented as odds ratios (ORs) with 95% confidence intervals (CIs). SPSS 17.0 for Windows (SPSS Inc., Chicago, IL, USA) was used for the analyses.

Results

Basic characteristics according to dementia status are shown in Table 1. Of the persons with dementia, 25% had had at least one osteoporotic fracture in the past 4 years, compared to 7% of the persons without dementia. In institutions, 31% had had at least one osteoporotic fracture, compared to 6% of the home-dwelling elderly. Hip fractures were the most common type of fracture and occurred in 16% of the persons with dementia and in 3% of the persons without dementia. In institutions, 19% of the elderly had experienced at least one hip fracture compared to 2% among the home-dwelling elderly. Both dementia and institutionalization were associated with osteoporotic fractures, after adjustment for age and sex (OR for dementia, 2.53; 95% CI, 1.82–3.50; and OR for institution, 4.08; 95% CI, 2.96–5.64). However, after additional adjustment for type of housing and dementia status, respectively, the association remained significant only for institutionalization (OR for dementia, 1.35; 95% CI, 0.92–1.99; and OR for institution, 3.53; 95% CI, 2.43–5.13). Furthermore, osteoporotic fractures were more common among women than among men; 11% of the women had had at least one osteoporotic fracture compared to 6% of the men. Female sex was associated with osteoporotic fractures (OR, 1.47; 95% CI, 1.04–2.09), after adjustment for age, dementia status, and type of housing.
Table 1

Basic characteristics of the study population (n = 2,610), according to dementia diagnosis

Characteristic

Non-dementia (n = 2305)

Dementia (n = 305)

p value

N

%

N

%

Women

1,506

(66.4)

255

(83.5)

<0.000

Mean age, years (SD)

77.0

(8.68)

88.7

(7.02)

<0.000

Mean MMSEa (SD)

28.4

(2.04)

12.5

(8.92)

<0.000

Living in institutions

106

(5.3)

186

(59.4)

<0.000

Fractures in the last 4 years

Any osteoporotic fracture

144

(6.9)

80

(25.4)

<0.000

Femur,

60

(2.9)

50

(15.9)

<0.000

Rib(s), sternum and thoracic pine

10

(0.6)

7

(2.4)

<0.000

Lumbar spine and pelvis

24

(1.2)

10

(3.6)

0.001

Shoulder and upper arm

15

(0.7)

9

(3.0)

<0.000

Forearm

24

(1.1)

9

(2.7)

0.016

Lower leg, including ankle

30

(1.3)

8

(2.4)

0.106

Mean number of drugs (SD)

4.27

(3.36)

6.28

(3.68)

<0.000

Use of any osteoporosis drugs

259

(12.0)

16

(5.4)

<0.000

Calcium/vitamin D combination

229

(10.7)

16

(5.4)

0.002

Raloxifene

18

(0.7)

0

(0)

0.113

Bisphosphonates

81

(3.8)

0

(0)

<0.000

Values are number of subjects and weighted proportion in parenthesis, unless otherwise indicated

aFive persons excluded with missing information about MMSE

Overall, 11% of the participants in this study used at least one osteoporosis drug. These drugs (mainly calcium/vitamin D combinations) were used by 5% of the persons with and 12% of the persons without dementia. In institutions, 8% used osteoporosis drugs compared to 12% of the home-dwelling elderly. Raloxifene was only used by women without dementia who lived in their own homes (n = 18). Bisphosphonates were also only used by persons without dementia; however, only one institutionalized person used these drugs.

Of persons with dementia, 10% with and 4% without a history of osteoporotic fractures used osteoporosis drugs. The corresponding percentages for persons without dementia were 15% (with fracture) and 12% (without fracture).

The logistic regression analyses (Table 2) showed that dementia was associated with a lower probability of use of osteoporosis drugs (OR, 0.34; 95% CI, 0.19–0.59), after adjustment for age, sex, osteoporotic fractures, and type of housing. The results changed only marginally when the people with severe dementia were excluded from the analysis. Living in an institution was also associated with a lower probability of use of osteoporosis drugs, after adjustment for age and sex, but the association was no longer statistically significant after additional adjustment for dementia status and osteoporotic fractures. Neither age nor osteoporotic fractures were associated with osteoporosis drug use. However, female sex was strongly associated with use of osteoporosis drugs, even after adjustment for age, osteoporotic fractures, dementia status, and type of housing.
Table 2

Odds ratios (ORs) with 95% confidence intervals (95% CIs) for use of osteoporosis drugs

 

Crude ORs (95% CI)

Age- and sex-adjusted ORs (95% CI)

All variables in the model ORs (95% CI)

Whole population (n = 2 610)

Age (continuous variable)

1.01 (0.99–1.02)

1.00 (0.98–1.01)

1.01 (0.99–1.03)

Female versus male

5.98 (3.88–9.20)

6.07 (3.93–9.37)

6.24 (4.04–9.64)

Presence of dementia

0.43 (0.27–0.70)

0.32 (0.19–0.53)

0.34 (0.19–0.59)

Any osteoporotic fracture

1.28 (0.87–1.89)

1.12 (0.75–1.68)

1.36 (0.90–2.06)

Living in institution versus own home

0.66 (0.43–1.01)

0.53 (0.34–0.84)

0.82 (0.49–1.36)

Subpopulation including only persons with MMSE ≥ 10 (n = 2,493)a

Age (continuous variable)

1.01 (1.00–1.03)

1.00 (0.99–1.02)

1.01 (1.00–1.03)

Female versus male

6.40 (4.12–9.94)

6.37 (4.09–9.92)

6.48 (4.16–10.1)

Presence of dementia

0.40 (0.22–0.74)

0.30 (0.16–0.57)

0.32 (0.17–0.60)

Any osteoporotic fracture

1.32 (0.87–2.00)

1.12 (0.73–1.73)

1.27 (0.82–1.97)

Living in institution versus own home

0.74 (0.45–1.21)

0.61 (0.36–1.02)

0.78 (0.46–1.34)

aExclusion of 117 individuals with MMSE < 10 (110 persons with dementia and seven persons with either MMSE <10 or missing value)

The analysis stratified by age (<80 and ≥80 years) showed that after adjustment for age, sex, type of housing, and osteoporotic fracture, dementia was significantly associated with a lower likelihood of use of osteoporosis drugs only among participants aged ≥80 years (OR for dementia age ≥80, 0.41; 95% CI, 0.23–0.74; OR for dementia age <80, 0.27; 95% CI, 0.04–1.99). The occurrence of dementia in the participants aged <80 years was low (n = 36; 2.5%).

Results from the stratified analysis by dementia status are presented in Table 3. Osteoporotic fractures were associated with use of osteoporosis drugs in persons with dementia but not in persons without dementia, after adjustment for age, sex, dementia, and type of housing. In addition, women were more likely to use osteoporosis drugs among persons without dementia but not among persons with dementia.
Table 3

Odds ratios (ORs) with 95% confidence intervals (95% CIs) for use of osteoporosis drugs in the two subgroups with and without a clinical diagnosis of dementia

 

Crude OR (95% CI)

All variables in the model (95% CI)

Non-dementia (n = 2305)

Age (continuous variable)

1.02 (1.01–1.04)

1.01 (1.00–1.03)

Female versus male

7.20 (4.55–11.4)

6.98 (4.41–11.1)

Any osteoporotic fracture

1.38 (0.88–2.17)

1.16 (0.72–1.85)

Living in institution versus own home

1.04 (0.59–1.82)

0.84 (0.47–1.51)

Dementia (n = 305)

Age (continuous variable)

0.98 (0.91–1.05)

0.97 (0.90–1.05)

Female versus male

1.14 (0.31–4.25)

1.18 (0.30–4.68)

Any osteoporotic fracture

2.65 (1.03–6.86)

3.10 (1.11–8.65)

Living in institution versus own home

0.92 (0.35–2.36)

0.68 (0.24–1.91)

Finally, we analysed the use of calcium alone and found that it was used by 2.7% of the persons without and among 1.5% of the persons with dementia. After adjustment for age, sex, osteoporotic fractures, and type of housing, dementia was not significantly associated with use of calcium (OR, 0.69; 95% CI, 0.24–2.00).

Discussion

Main findings

We found that the use of osteoporosis drugs was lower in persons with dementia than in persons without dementia, also after controlling for age, sex, osteoporotic fractures, and type of housing. This finding was not explained by low use among patients with severe dementia. Furthermore, osteoporotic fractures were more common among people with than without dementia. Taken together, this may indicate an undertreatment of osteoporosis in people with dementia. However, due to lack of statistical power, we could only confirm this finding in people aged ≥80 years, as there were few people with dementia below that age.

Few other studies have investigated the use of osteoporosis drugs in people with dementia. A US study of home-dwelling and institutionalized elderly showed that dementia was negatively associated with use of antiresorptive therapy, but only in ages 85 years and over [34]. Another US study did not find any association between osteoporosis drug use and cognitive impairment in nursing home residents [17]. Cognitive impairment was also negatively associated with osteoporosis therapy in a Canadian long-term care study [35]. In contrast, cognitive impairment in osteoporosis patients was associated with use of osteoporosis drugs in a Canadian home care population [36]. However, as we also included elderly in institutions, the study populations are not completely comparable. Possible explanations of the low use of osteoporosis drugs in people with dementia may be an underdiagnosis of osteoporosis and fear of polypharmacy in these frail elderly patients. Dementia may dominate the practitioner’s attention, leading to undertreatment of other conditions, such as osteoporosis [37]. Furthermore, bone mineral density testing is rarely performed among patients in nursing homes [38], where many people with dementia reside [37].

We found that osteoporotic fractures during the last 4 years were not significantly associated with use of osteoporosis drugs in the study population, although we cannot exclude that this may be explained by inadequate statistical power. Our finding indicates a low frequency of pharmacological prevention after a fracture, in spite of the high risk of subsequent fracture [39, 40]. Other studies have also reported a low use of osteoporosis drugs after fractures [20, 41]. When we analyzed the persons with and without dementia separately, we did, however, found an association between osteoporotic fractures and use of osteoporosis drugs among those with dementia. This finding, together with the lower use of osteoporosis drugs in the dementia group, may indicate that osteoporosis is often unrecognized in elderly with dementia until a fracture occurs.

We also found that use of osteoporosis drugs was lower in elderly subjects in institutions than among home-dwelling elderly, after adjustment for age and sex. However, after additional adjustment for dementia and osteoporotic fractures, the association was no longer statistically significant. This suggests that the lower use of osteoporosis drugs in institutions was partly explained by the high proportion of people with dementia in this setting. Low use of osteoporosis drugs in institutions has been reported previously [17], even though this population is at increased risk of vitamin D deficiency, osteoporosis, falls, and fractures [6, 4244]. In addition, a severe fracture is often a reason for institutionalization [45]. Female sex was strongly associated with use of osteoporosis drugs. This was seen also after adjustment for osteoporotic fractures, indicating that the higher use among women was not completely explained by the higher rate of fractures in women. Furthermore, the difference between men and women in use of osteoporosis drugs was more pronounced among persons without dementia. It is difficult to draw conclusions regarding gender differences due to the low rate of male participants in the subgroup analysis (e.g., two men with dementia used osteoporosis drugs). However, low use of osteoporosis drugs in men has been reported also by others [16, 17, 41, 46]. Although osteoporosis, fractures, and falls are more common in women [47], mortality after osteoporotic fractures is higher in men [48]. Hopefully, an increasing awareness of male osteoporosis will lead to an improved treatment with osteoporosis drugs in men in the future [16].

Another finding in our study was the differential use of the individual osteoporosis drugs in persons with and without dementia as well as in home-dwelling and institutionalized elderly. Calcium/vitamin D combinations were the most commonly used type of osteoporosis drug. Bisphosphonates and raloxifene were not used by persons with dementia, and bisphosphonates was used by only one institutionalized elderly. These discrepancies may have several explanations. Bisphosphonates and raloxifene were relatively new drugs when the baseline data for this study were collected. It is possible that fear of adverse side effects may lead to a hesitation to prescribe these new drugs to the frailest elderly. For example, patients with dementia may be more sensitive to serious adverse side effects of bisphosphonates [37]. Moreover, raloxifene is mainly used by postmenopausal women [49] and lacks hip fracture prevention data [2], which can explain the low use in persons with dementia and among institutionalized elderly. However, bisphosphonates and raloxifene are considered as more potent osteoporosis drugs than calcium/vitamin D combinations [1, 49]. Therefore, our results suggest not only that persons with dementia have a lower probability of receiving osteoporosis drugs but also that the treatment, when it occurs, may be less potent.

Limitations

First, the participants in this study lived in an urban area and were on average relatively well educated. These factors may affect the generalizability of our results. Second, the non-participants were on average slightly older than the participants and, therefore, probably more disabled and more likely to live in institutions [24]. On the other hand, some non-participants, particularly in the younger ages, were probably very healthy persons and not motivated to participate in a study about aging and health [50]. Third, participants or their relatives were asked about current drug use. If the participant resided in an institution, this information was provided from medical records. The different sources of information could affect the reported prevalence of drugs and diseases in the different groups, e.g., the number of drugs used by persons with dementia who lived in their own homes may be underestimated [51]. On the other hand, an advantage of using self-report is that the use of over the counter drugs (e.g., calcium/vitamin D supplements) is taken into account. Finally, we did unfortunately not have information about bone mass or biochemical bone turnover markers. However, we did have information about osteoporotic fractures, obtained from the computerized Swedish National Patient Register, which covers all hospitals in Sweden. Almost all fractures in Sweden are treated in hospitals and are thereby included in that register. Although we analysed fractures known to be related to osteoporosis [27], some of them might have occurred in the absence of osteoporosis. However, given the high age of the study population, we assume that most of the fractures were osteoporotic.

Conclusions

Use of osteoporosis drugs was low in this study of older people. Persons with dementia had a higher prevalence of osteoporotic fractures, but were less likely to use osteoporosis drugs than persons without dementia. This finding was not explained by low use among patients with severe dementia. Furthermore, not only do persons with dementia have a lower probability of receiving osteoporosis drugs, but the treatment, when it occurs, may be less potent.

In summary, our findings indicate an underdiagnosis and undertreatment of osteoporosis in persons with dementia, although osteoporotic fractures are common among these patients.

Acknowledgments

The Swedish National study on Aging and Care, SNAC, (http://www.snac.org) is financially supported by the Ministry of Health and Social Affairs, Sweden and the participating county councils, municipalities, and university departments. We are grateful to the participants, the participating counties, and municipalities. We want to thank the members of the SNAC-K Project Study Group for data collection and collaboration. We also wish to thank Associate Professor Ingemar Kåreholt for statistical advice. This study was supported by grants from the Swedish Research Council, the Swedish Council for Working Life and Social Research, and Karolinska Institutet KID-grant.

Conflicts of interest

None.

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2011