The interaction of ethnicity and chronic disease as risk factors for osteoporotic fractures: a comparison in Canadian Aboriginals and non-Aboriginals

The prevalence of patients treated for osteoporosis in Greenland is low compared to Denmark

The study is a register-based cross-sectional study aiming to estimate the prevalence of treated osteoporosis in Greenland compared to Denmark and provide a description of the patients with osteoporosis in Greenland. In addition, the study estimates the incidence of hip fractures in Greenland from 2018 to 2020 among people aged 65 years or older. The overall prevalence of patients prescribed medication for osteoporosis among those aged 18 years or older was 0.56% in Greenland and 2.36% in Denmark (p < 0.001). Among those aged 50 years or older, the prevalence was 1.28% and 4.71% in Greenland and Denmark, respectively (p < 0.001). The prevalence increased to 3.41% and 11.18% among patients aged 80 years or older in Greenland and Denmark, respectively. The incidence of hip fractures in Greenland was 6.55 per 1,000 inhabitants in 2020 compared to 5.65 per 1,000 inhabitants in Denmark (NS). In conclusion, the prevalence of treated osteoporosis in Greenland was less than one in four of that of Denmark. The incidence of hip fractures was similar in Greenland than in Denmark. Hence, our findings suggest that a marked number of subjects with osteoporosis in Greenland go untreated.

The intersectional role of social stress in fracture risk: results from the Women's Health Initiative

BACKGROUND

The biological consequences of stress from the social environment pattern health outcomes. This study investigated whether social stress is prospectively associated with fracture incidence among racially and ethnically diverse, postmenopausal women.

METHODS

Data from 160 709 postmenopausal women in the Women's Health Initiative was analysed using Cox proportional hazards regression models to examine prospective associations of social stress with time to total and hip fracture incidence. Self-reported questionnaires measuring social strain, social functioning and social support were used to assess social stress.

RESULTS

Age and race/ethnicity modified associations between social stress and total and hip fractures. HRs for the associations between higher social support (indicating lower social stress) and total fractures among those age 50-59 years were 0.92 (95% CI: 0.90 to 0.94); HR=0.94 (95% CI: 0.93 to 0.95) for those age 60-69 years and HR=0.96 (95% CI: 0.95 to 0.98) for those age 70-79 years. Higher social strain was associated with greater hip fracture incidence among Native American women (HR=1.84, 95% CI: 1.10 to 3.10), Asian women (HR=1.37, 95% CI: 1.01 to 1.86) and white women (HR=1.04, 95% CI: 1.01 to 1.08).

CONCLUSION

Identifying population patterns of fracture incidence as biological expressions of social environments reveals how race/ethnic specific social environmental factors influence disparities in fractures.

Relationship of American Indian blood quantum with osteoporosis risk: a cross-sectional study of American Indian women in Oklahoma

Information regarding the prevalence and risk of osteoporosis among American Indian (AI) women is limited. This study showed that with increasing AI blood quantum, the prevalence of osteoporosis at the hip based on BMD T-scores decreased and this appeared to be independent of other risk factors.

INTRODUCTION

This study was designed to investigate the effects of AI blood quantum (BQ) on osteoporosis prevalence and risk in a cohort of AI women in Oklahoma.

METHODS

Women (n = 301), aged 50 years and older, were recruited to participate in the Oklahoma American Indian Women's Osteoporosis Study. Baseline bone density, fracture history, bone biochemical markers, and potential risk factors were assessed. Participants were stratified by AI BQ into BQ1 ≤ 25%, BQ2 = 25-49%, BQ3 = 50-74%, and BQ4 = 75-100%. The effects of BQ on the prevalence and risk of osteoporosis were evaluated.

RESULTS

Based on T-scores, one in approximately eight women in the study was osteoporotic at one or more sites. The prevalence of osteoporosis decreased (p < 0.05) with increasing BQ, especially at the hip, trochanteric, and intertrochanter regions. No differences in bone-specific alkaline phosphatase and C-telopeptide were observed across BQ that could account for the differences in bone density. 25-OH vitamin D decreased with increasing BQ, but mean for each BQ1-4 was > 40 ng/mL. Fracture history did not differ across BQ, and though 52% of the population consumed less than the RDA for calcium, no effect of BQ was observed.

CONCLUSIONS

In this cohort of women who identified as AI, greater Indian BQ was associated with a decrease in the prevalence of osteoporosis.

Musculoskeletal health of Indigenous Australians

INTRODUCTION

Research on non-communicable diseases (NCD) in Indigenous Australians has mostly focused on diabetes mellitus and chronic kidney or cardiovascular disease. Osteoporosis, characterised by low bone mass and structural deterioration of bone tissue, and sarcopenia, the age-related loss of muscle mass and strength, often co-exist with these common NCDs-the combination of which will disproportionately increase bone fragility and fracture risk and negatively influence cortical and trabecular bone. Furthermore, the social gradient of NCDs, including osteoporosis and fracture, is well-documented, meaning that specific population groups are likely to be at greater risk of poorer health outcomes: Indigenous Australians are one such group.

PURPOSE

This review summarises the findings reported in the literature regarding the muscle and bone health of Indigenous Australians.

FINDINGS

There are limited data regarding the musculoskeletal health of Indigenous Australians; however, areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) is reported to be greater at the hip compared to non-Indigenous Australians. Falls are the leading cause of injury-related hospitalisations in older Australians, particularly Indigenous Australians, with a great proportion suffering from fall-related fractures. Despite sparse data, it appears that Indigenous men and women have a substantially higher risk of hip fracture at a much younger age compared to non-Indigenous Australians.

CONCLUSION

Data on more detailed musculoskeletal health outcomes are required in Indigenous Australians to better understand fracture risk and to formulate evidence-based strategies for fracture prevention and to minimise the risk of falls.

Fractures in indigenous compared to non-indigenous populations: A systematic review of rates and aetiology

BACKGROUND

Compared to non-indigenous populations, indigenous populations experience disproportionately greater morbidity, and a reduced life expectancy; however, conflicting data exist regarding whether a higher risk of fracture is experienced by either population. We systematically evaluate evidence for whether differences in fracture rates at any skeletal site exist between indigenous and non-indigenous populations of any age, and to identify potential risk factors that might explain these differences.

METHODS

On 31 August 2016 we conducted a comprehensive computer-aided search of peer-reviewed literature without date limits. We searched PubMed, OVID, MEDLINE, CINAHL, EMBASE, and reference lists of relevant publications. The protocol for this systematic review is registered in PROSPERO, the International Prospective Register of systematic reviews (CRD42016043215). Using the World Health Organization reference population as standard, hip fracture incidence rates were re-standardized for comparability between countries.

RESULTS

Our search yielded 3227 articles; 283 potentially eligible articles were cross-referenced against predetermined criteria, leaving 27 articles for final inclusion. Differences in hip fracture rates appeared as continent-specific, with lower rates observed for indigenous persons in all countries except for Canada and Australia where the opposite was observed. Indigenous persons consistently had higher rates of trauma-related fractures; the highest were observed in Australia where craniofacial fracture rates were 22-times greater for indigenous compared to non-indigenous women. After adjustment for socio-demographic and clinical risk factors, approximately a three-fold greater risk of osteoporotic fracture and five-fold greater risk of craniofacial fractures was observed for indigenous compared to non-indigenous persons; diabetes, substance abuse, comorbidity, lower income, locality, and fracture history were independently associated with an increased risk of fracture.

CONCLUSIONS

The observed paucity of data and suggestion of continent-specific differences indicate an urgent need for further research regarding indigenous status and fracture epidemiology and aetiology. Our findings also have implications for communities, governments and healthcare professionals to enhance the prevention of trauma-related fractures in indigenous persons, and an increased focus on modifiable lifestyle behaviours to prevent osteoporotic fractures in all populations.

Osteoporosis management and fractures in the Métis of Ontario, Canada

Half of Métis citizens, compared to less than 10 % of the general population of Ontario, reside in northern regions, with little access to bone mineral density (BMD) testing. Métis citizens had lower sex-specific and age-standardized rates of BMD testing, yet similar rates of fracture (both sexes) and pharmacotherapy (women only).

PURPOSE

To examine osteoporosis management and common osteoporosis-related fractures among Métis citizens compared to the general population of older adults residing in Ontario.

METHODS

We linked healthcare (medical and pharmacy) utilization and administrative (demographic) databases with the Métis Nation of Ontario citizenship registry to estimate osteoporosis management (bone mineral density [BMD] testing, pharmacotherapy) and fractures (hip, humerus, radius/ulna) among adults aged ≥50 years, from April 1, 2006 to March 31, 2011. Pharmacotherapy data were limited to residents aged ≥65 years. Sex-specific and age-standardized rates were compared between the Métis and the general population. Multivariable logistic regression was used to compare rates of BMD testing after controlling for differences in age and region of residence between the Métis and the general population.

RESULTS

We studied 4219 Métis citizens (55 % men), and 140 (3 %) experienced a fracture. Half of Métis citizens, compared to less than 10 % of the general population of Ontario, resided in northern regions. We identified significantly lower sex-specific and age-standardized rates of BMD testing among Métis compared to the general population, yet found little difference in fracture rates (both sexes) or pharmacotherapy (women only). Differences in BMD testing disappeared after adjusting for region of residence among women yet remained significant among men.

CONCLUSIONS

Despite finding significantly lower rates of osteoporosis management among men, Métis men and women were found to have similar age-standardized fracture rates to the general population.

Associations between adverse social position and bone mineral density in women aged 50 years or older: data from the Manitoba Bone Density Program

We examined the independent contribution of income to low bone mineral density in women aged 50 years and older. A significant dose-response association was observed between low income and low (bone mineral density) BMD, which was not explained by clinical risk factors or osteoporotic treatment in the year prior.

INTRODUCTION

The association between social disadvantage and osteoporosis is attracting increased attention; however, little is known of the role played by income. We examined associations between income and bone mineral density (BMD) in 51,327 women aged ≥50 years from Manitoba, Canada.

METHODS

Low BMD was defined as a T-score ≥2.5SD (femoral neck or minimum) measured by dual energy X-ray absorptiometry (DXA) 1996-2001. Mean household income was extracted from Canada Census 2006 public use files and categorized into quintiles. Age, weight and height were recorded at time of DXA. Parental hip fracture was self-reported. Diagnosed comorbidities, including osteoporotic fracture and rheumatoid arthritis, were ascertained from hospital records and physician billing claims. Chronic obstructive pulmonary disease was used as a proxy for smoking and alcohol abuse as a proxy for high alcohol intake. Corticosteroid use was obtained from the comprehensive provincial pharmacy system. Logistic regression was used to assess relationships between income (highest income quintile held as referent) and BMD, accounting for clinical risk factors.

RESULTS

Compared to quintile 5, the adjusted odds ratio (OR) for low BMD at femoral neck for quintiles 1 through 4 were, respectively, OR1.41 (95%CI 1.29-1.55), OR1.32 (95%CI 1.20-1.45), OR1.19 (95%CI 1.08-1.30) and OR1.10 (95%CI 1.00-1.21). Similar associations were observed when further adjustment was made for osteoporotic drug treatment 12 months prior and when low BMD was defined by minimum T-score.

CONCLUSIONS

Lower income was associated with lower BMD, independent of clinical risk factors. Further work should examine whether lower income increases the likelihood of treatment qualification.

Dioxin-like compounds and bone quality in Cree women of Eastern James Bay (Canada): a cross-sectional study

BACKGROUND

Aboriginal populations living in Canada's northern regions are exposed to a number of persistent organic pollutants through their traditional diet which includes substantial amounts of predator fish species. Exposure to dioxin-like compounds (DLCs) can cause a variety of toxic effects including adverse effects on bone tissue. This descriptive cross-sectional study was conducted to investigate the relationship between plasma concentrations of DLCs and bone quality parameters in Cree women of Eastern James Bay (Canada).

METHODS

Two hundred and forty-nine Cree women from seven communities in Eastern James Bay (Canada), aged 35 to 74 years old, participated in the study. In order to determine the total DLC concentration in plasma samples of participants, we measured the aryl hydrocarbon receptor-mediated transcriptional activity elicited by plasma sample extracts using a luciferase reporter gene assay. Plasma concentrations of mono-ortho-substituted dioxin-like polychlorinated biphenyls (DL-PCBs) 105, 118 and 156 were measured by gas chromatography-mass spectrometry. Bone quality parameters (speed of sound, m/s; broadband ultrasound attenuation, dB/MHz; stiffness index, %) were assessed by quantitative ultrasound at the right calcaneus with the Achilles InSight system. Several factors known to be associated with osteoporosis were documented by questionnaire. Multiple linear regression models were constructed for the three ultrasound parameters.

RESULTS

DL-PCBs 105 and 118 concentrations, but not the global DLC concentration, were inversely associated with the stiffness index, even after adjusting for several confounding factors. The stiffness index (log) decreased by -0.22% (p=0.0414) and -0.04% (p=0.0483) with an increase of one μg/L in plasma concentrations of DL-PCB 105 and DL-PCB 118, respectively. Other factors, including age, height, smoking status, menopausal status and the percentage of omega-6 polyunsaturated fatty acids (PUFAs) in erythrocyte membranes were negatively associated with one of the ultrasound parameters, while the percentage of omega-3 PUFAs in these membranes and levels of physical activity and education were positively associated with them.

CONCLUSIONS

Our results show that an increase in plasma concentrations of DL-PCBs 105 and 118 was negatively associated with stiffness index, a measure of bone quality/strength, in women of this population. In addition to environmental contaminants, future studies should also consider PUFA intake as a factor influencing bone quality.

The contributions of First Nations ethnicity, income, and delays in surgery on mortality post-fracture: a population-based analysis

We examined the independent contributions of First Nations ethnicity and lower income to post-fracture mortality. A similar relative increase in mortality associated with fracture appears to translate into a larger absolute increase in post-fracture mortality for First Nations compared to non-First Nations peoples. Lower income also predicted increased mortality post-fracture.

INTRODUCTION

First Nations peoples have a greater risk of mortality than non-First Nations peoples. We examined the independent contributions of First Nations ethnicity and income to mortality post-fracture, and associations with time to surgery post-hip fracture.

METHODS

Non-traumatic fracture cases and fracture-free controls were identified from population-based administrative data repositories for Manitoba, Canada (aged≥50 years). Populations were retrospectively matched for sex, age (within 5 years), First Nations ethnicity, and number of comorbidities. Differences in mortality post-fracture of hip, wrist, or spine, 1996-2004 (population 1, n=63,081), and the hip, 1987-2002(Population 2, n=41,211) were examined using Cox proportional hazards regression to model time to death. For hip fracture, logistic regression analyses were used to model the probability of death within 30 days and 1 year.

RESULTS

Population 1: First Nations ethnicity was associated with an increased mortality risk of 30-53% for each fracture type. Lower income was associated with an increased mortality risk of 18-26%. Population 2: lower income predicted mortality overall (odds ratio (OR) 1.15, 95% confidence interval (CI) 1.07-1.23) and for hip fracture cases (OR 1.18, 95%CI 1.05-1.32), as did older age, male sex, diabetes, and >5 comorbidities (all p≤0.01). Higher mortality was associated with pertrochanteric fracture (OR 1.14, 95% CI 1.03-1.27), or surgery delay of 2-3 days (OR 1.34, 95% CI 1.18-1.52) or ≥4 days (OR 2.35, 95% CI 2.07-2.67).

CONCLUSION

A larger absolute increase in mortality post-fracture was observed for First Nations compared to non-First Nations peoples. Lower income and surgery delay>2 days predicted mortality post-fracture. These data have implications regarding prioritization of healthcare to ensure targeted, timely care for First Nations peoples and/or individuals with lower income.

Clinical risk factors for osteoporosis are common among elderly people in Nuuk, Greenland

Background

Osteoporosis is a debilitating condition characterized by fractures, pain and premature death. Risk factors for osteoporosis predict the risk of fragility fractures.

Aim

To describe the occurrence of risk factors for osteoporosis among populations in Nuuk, the capital of Greenland.

Methods

A random sample of women born in 1934–42, 1945–47, 1956, and men born in 1956 were selected from the national civil registry. A questionnaire was sent out in Greenlandic and Danish on risk factors for osteoporosis: family history, smoking habits, alcohol intake, presence of disease, sun exposure, intake of dairy products, age at menopause (women) and number of falls. Additional questions included the frequency of back pain, previous fractures, intake of vitamin D and calcium supplements, use of anti-osteoporotic drugs, steroids and other drugs.

Results

The questionnaire was sent to 317 subjects confirmed to be living at an address in Nuuk and 181 (57.1%) responded. More young women than older women were smokers (60.6% vs. 35.0%; p=0.022) while limited sun exposure was reported by more of the old women (37.2% vs. 5.6%; p=0.003). Family history of osteoporosis was reported by 15.0%, without difference between groups. Alcohol and milk intake did not differ between groups. Premature menopause was reported by 17.9% of the women. Falls within the last year were reported by 42.4% with fewer falls in the oldest age group (21.9% vs. 50.0%; p=0.005). Frequency of fragility fractures increased with age (5.7% vs. 24.3% vs. 30.4%; p=0.02) and the risk of a fragility fracture increased with age (p=0.004; OR, 95% CI: 4.5, 1.6–12.2, reference: below 70 years), when adjusted for smoking, gender and falls. The use of anti-osteoporotic drugs was low (3.4%) while 28.8% took calcium and vitamin D supplements.

Conclusions

Age is a dominating risk factor for fragility fractures in Greenland. The use of anti-osteoporotic drugs is low in Greenland, even if osteoporotic fractures are common in old age.

Clinical review: Ethnic differences in bone mass--clinical implications

CONTEXT

Differences in bone mineral density (BMD) as assessed with dual-energy x-ray absorptiometry are observed between geographic and ethnic groups, with important implications in clinical practice.

EVIDENCE ACQUISITION

PubMed was employed to identify relevant studies. A review of the literature was conducted, and data were summarized and integrated.

EVIDENCE SYNTHESIS

The available data highlight the complex ethnic variations in BMD, which only partially account for observed variations in fracture rates. Factors contributing to ethnic differences include genetics, skeletal size, body size and composition, lifestyle, and social determinants. Despite BMD differences, the gradient of risk for fracture from BMD and other clinical risk factors appears to be similar across ethnic groups. Furthermore, BMD variation is greater within an ethnic population than between ethnic populations. New imaging technologies have identified ethnic differences in bone geometry, volumetric density, microarchitecture, and estimated bone strength that may contribute to a better understanding of ethnic differences in fracture risk.

CONCLUSIONS

Factors associated with ethnicity affect BMD and fracture risk through direct and indirect mechanisms.

Ankle fractures do not predict osteoporotic fractures in women with or without diabetes

It is not clear whether ankle fractures predict future osteoporotic fractures in women, and whether diabetes influences this relationship. We found that a prior ankle fracture does not predict subsequent osteoporotic fractures in women with or without diabetes.

INTRODUCTION

We aimed to determine: (1) whether a prior ankle fracture was a risk factor for a subsequent major osteoporotic fracture in older women; (2) whether this risk was modified by the presence of diabetes; (3) the risk factors for ankle fracture in older women.

METHODS

We identified 3,054 women age 50 years and older with diabetes and 9,151 matched controls using the Manitoba Bone Density Program database. Multivariable regression models were used to examine factors associated with prior ankle fracture, and the importance of prior ankle fracture as a predictor of subsequent major osteoporotic fracture during a mean 4.8 years of observation.

RESULTS

A prior ankle fracture was not a significant predictor of subsequent major osteoporotic fracture for women with diabetes (hazard ratio [HR] 1.13; 95% confidence interval [CI], 0.68-1.83; p = 0.623) or women without diabetes (HR 1.16; 95% CI, 0.79-1.71; p = 0.460), and there was no interaction between diabetes and ankle fracture after pooling all women in the cohort (p = 0.971). The presence of diabetes was not independently associated with prior ankle fracture (adjusted odds ratio [OR] 1.14 [95% CI, 0.93-1.38], p = 0.200), whereas higher body mass index (adjusted OR 1.04 per standard deviation increase [95% CI, 1.03-1.06], p < 0.001), previous major osteoporotic fracture (adjusted OR 1.40 [95% CI, 1.13-1.75], p = 0.002), and multiple comorbidities (>6 ambulatory diagnostic groups) (adjusted OR 1.81 [95% CI, 1.40-2.36], p < 0.001) were related to prior ankle fracture.

CONCLUSIONS

Ankle fracture was not a significant predictor of major osteoporotic fracture in women, and a diagnosis of diabetes did not influence the relationship.

The post-fracture care gap among Canadian First Nations peoples: a retrospective cohort study

Despite targeted attempts to reduce post-fracture care gaps, we hypothesized that a larger care gap would be experienced by First Nations compared to non-First Nations people. First Nations peoples were eight times less likely to receive post-fracture care compared to non-First Nations peoples, representing a clinically significant ethnic difference in post-fracture care.

INTRODUCTION

First Nations peoples are the largest group of aboriginal (indigenous or native) peoples in Canada. Canadian First Nations peoples have a greater risk of fracture compared to non-First Nations peoples. We hypothesized that ethnicity might be associated with a larger gap in post-fracture care.

METHODS

Non-traumatic major osteoporotic fractures for First Nations and non-First Nations peoples aged ≥ 50 years were identified from a population-based data repository for Manitoba, Canada between April 1996 and March 2002. Logistic regression analysis was used to examine the probability of receiving a BMD test, a diagnosis of osteoporosis, or beginning an osteoporosis-related drug in the 6 months post-fracture.

RESULTS

A total of 11,234 major osteoporotic fractures were identified; 502 occurred in First Nations peoples. After adjustment for confounding covariates, First Nations peoples were less likely to receive a BMD test [odds ratio (OR) 0.1, 95% confidence interval (CI), 0.0-0.5], osteoporosis-related drug treatment (OR, 0.5; 95% CI, 0.3-0.7), or a diagnosis of osteoporosis (OR, 0.5; 95% CI, 0.3-0.7) following a fracture compared to non-First Nations peoples. Females were more likely to have a BMD test (OR, 5.0; 95% CI, 2.6-9.3), to be diagnosed with osteoporosis (OR, 1.7; 95% CI, 1.5-2.0), and to begin drug treatment (OR, 4.1; 95% CI, 2.7-6.4) compared to males.

CONCLUSIONS

An ethnicity difference in post-fracture care was observed. Further work is needed to elucidate underlying mechanisms for this difference and to determine whether failure to initiate treatment originates with the medical practitioner, the patient, or a combination of both. It is imperative that all residents of Manitoba receive efficacious and equal care post-fracture, regardless of ethnicity.

Bone microarchitecture assessed by TBS predicts osteoporotic fractures independent of bone density: the Manitoba study

The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the "gold standard" for diagnosing osteoporosis but does not directly reflect deterioration in bone microarchitecture. The trabecular bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of bone microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women.

Performance of comorbidity measures for predicting outcomes in population-based osteoporosis cohorts

The performance of five comorbidity measures, including the Charlson and Elixhauser indices, was investigated for predicting mortality, hospitalization, and fracture outcomes in two osteoporosis cohorts defined from administrative databases. The optimal comorbidity measure depended on the outcome of interest, although overall the Elixhauser index performed well.

INTRODUCTION

Studies that use administrative data to investigate population-based health outcomes often adopt risk-adjustment models that include comorbidities, conditions that coexist with the index disease. There has been limited research about the measurement of comorbidity in osteoporotic populations. The study purpose was to compare the performance of comorbidity measures for predicting mortality, fracture, and health service utilization outcomes in two cohorts with diagnosed or treated osteoporosis.

METHODS

Administrative data were from the province of Saskatchewan, Canada. Osteoporosis cohorts were identified from diagnoses in hospital and physician data and prescriptions for osteo-protective medications using case definitions with high sensitivity or high specificity. Five diagnosis- and medication-based comorbidity measures and five 1-year outcomes, including mortality, hospitalization (two measures), osteoporotic-related fracture, and hip fracture, were defined. Performance of the comorbidity measures was assessed using the c-statistic (discrimination) and Brier score (prediction error) for multiple logistic regression models.

RESULTS

In the specific cohort (n = 9,849) for the mortality outcome, the Elixhauser index resulted in the largest improvement (8.96%) in the c-statistic and lowest Brier score compared to a model that contained demographic and socioeconomic variables, followed by the Charlson index (6.06%). For hospitalization, the number of different diagnoses resulted in the largest improvement (14.01%) in the c-statistic. The Elixhauser index resulted in significant improvements in the c-statistic for osteoporosis-related and hip fractures. Similar results were observed for the sensitive cohort (n = 28,068).

CONCLUSIONS

Recommendations about the optimal comorbidity measure will vary with the outcome under investigation. Overall, the Elixhauser index performed well.

Direct costs of fractures in Canada and trends 1996-2006: a population-based cost-of-illness analysis

Cost-of-illness (COI) analysis is used to evaluate the economic burden of illness in terms of health care resource (HCR) consumption. We used the Population Health Research Data Repository for Manitoba, Canada, to identify HCR costs associated with 33,887 fracture cases (22,953 women and 10,934 men) aged 50 years and older that occurred over a 10-year period (1996-2006) and 101,661 matched control individuals (68,859 women and 32,802 men). Costs (in 2006 Canadian dollars) were estimated for the year before and after fracture, and the change (incremental cost) was modeled using quantile regression analysis to adjust for baseline covariates and to study temporal trends. The greatest total incremental costs were associated with hip fractures (median $16,171 in women and $13,111 for men), followed by spine fractures ($8,345 in women and $6,267 in men). The lowest costs were associated with wrist fractures ($663 in women and $764 in men). Costs for all fracture types were greater in older individuals (p < 0.001). Similar results were obtained with regression-based adjustment for baseline factors. Some costs showed a slight increase over the 10 years. The largest temporal increase in women was for hip fracture ($13 per year, 95% CI $6-$21, p < 0.001) and in men was for humerus fracture ($11 per year, 95% CI $3-$19, p = 0.007). At the population level, hip fractures were responsible for the largest proportion of the costs after age 80, but the other fractures were more important prior to age 80. We found that there are large incremental health care costs associated with incident fractures in Canada. Identifying COI from HCR use offers a cost baseline for measuring the effects of evidence-based guidelines implementation.

Mortality rates after incident non-traumatic fractures in older men and women

Non-traumatic fractures at typical osteoporotic sites are associated with increased mortality across all age groups, particularly in men. Furthermore, in certain age subgroups of women and men, this rate remained elevated beyond 5 years for fractures of the hip, vertebrae, humerus, and other sites.

INTRODUCTION

Increased mortality rates have been documented following non-traumatic hip, vertebral, and shoulder fractures. However, data are lacking as to the duration of excess mortality and whether there is increased mortality following fractures at other sites. We determined mortality up to 15 years following incident fractures at typical osteoporotic sites.

METHODS

Using healthcare databases for the Province of Manitoba, Canada, we identified individuals 50 years and older with an incident non-traumatic fracture between 1986 and 2007. Each fracture case was matched to three fracture-free controls. Generalized linear models were used to test for trends in mortality and to estimate the relative risk for cases after adjusting for co-morbidity and living arrangements.

RESULTS

During the study period, we identified 21,067 incident fractures in men followed by 10,724 (50.1%) deaths and 49,197 incident fractures in women followed by 22,018 deaths (44.8%). Seventy-six percent of the fractures were at sites other than the hip and vertebrae. After adjustment for age, number of co-morbidities, and level of dependence in living arrangements, the risk of death in cases, relative to controls, was increased in both sexes for hip, vertebral, humerus, wrist (in men only), and other fracture sites. Post-fracture mortality was higher in men than women. Relative mortality was the highest in the younger age groups across the spectrum of fracture sites.

CONCLUSIONS

Fractures at typical osteoporotic sites are associated with increased mortality across all age groups, particularly in men. Better understanding of factors associated with increased post-fracture mortality should inform the development of management strategies.

Risk of low bone mineral density associated with psychotropic medications and mental disorders in postmenopausal women

BACKGROUND

Independent reports suggest that various psychotropic medications and psychiatric disorders are associated with changes in bone mineral density (BMD). The objective of this study was to clarify the independent effects of a range of mental illnesses and psychotropic medications on BMD among postmenopausal women.

METHODS

Women 50 years or older with baseline BMD measured by dual-energy x-ray absorptiometry were identified in a database containing all clinical dual-energy x-ray absorptiometry test results for the Province of Manitoba, Canada. Records were linked with population-based administrative health databases to provide detailed information on sociodemographic factors, mental and physical health diagnoses, and prescription medication usage. Osteoporotic cases (n = 6820) were matched on age, sex, and ethnicity to 3 control subjects with normal BMD (n = 20,247). Multivariable conditional logistic regression compared cases and control subjects on diagnosed mental illnesses and use of psychotropic medications.

RESULTS

Selective serotonin reuptake inhibitors (adjusted odds ratios, 1.46; 95% confidence interval [CI], 1.25-1.69), atypical antipsychotics (AOR, 1.55; 95% CI, 1.06-2.28), and benzodiazepines (AOR, 1.17; 95% CI, 1.06-1.29) were associated with higher risk of osteoporosis. Tricyclic antidepressants were associated with lower odds of osteoporosis (AOR, 0.57; 95% CI, 0.49-0.65). These drug effects were independent of mental illness diagnoses including depression (AOR, 0.86; 95% CI, 0.75-0.98) and schizophrenia (AOR, 1.98; 95% CI, 1.04-3.77).

CONCLUSIONS

Some psychotropic medications are associated with an increased risk of osteoporotic BMD, whereas tricyclic antidepressants may be protective against osteoporosis, and these effects are independent of mental illness diagnoses. Clinicians should consider these effects when prescribing psychotropic medications in postmenopausal women.

Tamoxifen Use and Osteoporotic Fracture Risk: A Population-Based Analysis

Purpose

Although tamoxifen has been shown to increase bone mineral density in clinical trials, it is less clear whether this significantly affects fracture rates. Even fewer data are available on skeletal outcomes when tamoxifen is used outside of the context of a clinical trial. A population-based case-control study was undertaken to determine whether tamoxifen use is associated with osteoporotic fractures in routine clinical practice.

Patients and Methods

Population-based administrative data for the Province of Manitoba, Canada, were examined for tamoxifen use and nontraumatic fracture codes in women 50 years of age or older. Women with osteoporotic fractures (vertebral, wrist or hip; n = 11,096) from 1996 to 2004 were each compared with three controls without fracture, matched for age, ethnicity, and comorbidity (n = 33,209). Tamoxifen use was classified as never, past use, or current use.

Results

Lower osteoporotic fracture rates were associated with current tamoxifen use (univariate odds ratio [OR] = 0.68; 95% CI, 0.55 to 0.84). After controlling for demographic and medical diagnoses known to affect fracture risk, current use was associated with a significantly reduced overall osteoporotic fracture risk (adjusted OR = 0.68; 95% CI, 0.55 to 0.88) and of hip fractures (adjusted OR = 0.47; 95% CI, 0.28 to 0.77). Neither recent nor remote past tamoxifen use was associated with reduced osteoporotic fracture risk. Breast cancer was not independently associated with osteoporotic fractures (adjusted OR = 0.95; 95% CI, 0.81 to 1.12).

Conclusion

In a population-based case-control study, current tamoxifen use was associated with a substantial reduction in osteoporotic fractures.

Fracture risk from psychotropic medications: a population-based analysis

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, and antipsychotics have each been associated with an increased risk of fracture in older individuals. The aim of this study was to better define the magnitude of fracture risk with psychotropic medications and to determine whether a dose-effect relationship exists.

METHODS

Population-based administrative databases were used to examine psychotropic medication exposure and fractures in persons aged 50 years and older in Manitoba between 1996 and 2004. Persons with osteoporotic fractures (vertebral, wrist, or hip [n = 15,792]) were compared with controls (3 controls for each case matched for age, sex, ethnicity, and comorbidity [n = 47,289]). Medications examined included antidepressants (SSRIs vs other monoamines), antipsychotics, lithium, and benzodiazepines.

RESULTS

Selective serotonin reuptake inhibitors were associated with the highest adjusted odds of osteoporotic fractures (odds ratio [OR] = 1.45; 95% confidence interval [CI], 1.32-1.59). Other monoamine antidepressants (OR = 1.15; 95% CI, 1.07-1.24) and benzodiazepines (OR = 1.10; 95% CI, 1.04-1.16) were also associated with greater fracture risk, although the relationship was weaker. Lithium was associated with lower fracture risk (OR = 0.63; 95% CI, 0.43-0.93), whereas the relationship with antipsychotics was not significant in the models that adjusted for diagnoses. A dose-effect relationship was seen with SSRIs and benzodiazepines.

CONCLUSIONS

This study provides novel insight into the relationship between fractures and psychotropic medications in the elderly. Selective serotonin reuptake inhibitors seem to have a greater risk than other psychotropic classes, and higher doses may further increase that risk. Lithium seems to be protective against fractures.

Using multiple data features improved the validity of osteoporosis case ascertainment from administrative databases

OBJECTIVES

The aim was to construct and validate algorithms for osteoporosis case ascertainment from administrative databases and to estimate the population prevalence of osteoporosis for these algorithms.

STUDY DESIGN AND SETTING

Artificial neural networks, classification trees, and logistic regression were applied to hospital, physician, and pharmacy data from Manitoba, Canada. Discriminative performance and calibration (i.e., error) were compared for algorithms defined from different sets of diagnosis, prescription drug, comorbidity, and demographic variables. Algorithms were validated against a regional bone mineral density testing program.

RESULTS

Discriminative performance and calibration were poorer and sensitivity was generally lower for algorithms based on diagnosis codes alone than for algorithms based on an expanded set of data features that included osteoporosis prescriptions and age. Validation measures were similar for neural networks and classification trees, but prevalence estimates were lower for the former model.

CONCLUSION

Multiple features of administrative data generally resulted in improved sensitivity of osteoporosis case-detection algorithm without loss of specificity. However, prevalence estimates using an expanded set of features were still slightly lower than estimates from a population-based study with primary data collection. The classification methods developed in this study can be extended to other chronic diseases for which there may be multiple markers in administrative data.

Exclusion of focal vertebral artifacts from spine bone densitometry and fracture prediction: a comparison of expert physicians, three computer algorithms, and the minimum vertebra

Expert physicians and automated methods for the exclusion of vertebral levels in DXA scans containing focal artifacts were compared. All methods of vertebral exclusion led to a small improvement in fracture prediction. Computer algorithms performed at least as well as physicians.

INTRODUCTION

Lumbar spine DXA is often confounded by focal artifacts. Clinical rules and automated methods for vertebral exclusion have been proposed, but their concordance, effect on diagnosis, and fracture prediction is unknown.

MATERIALS AND METHODS

We analyzed clinical DXA scans of the lumbar spine (20,478 women and 1534 men) performed from 1998 to 2002 (Province of Manitoba, Canada). Longitudinal health service records were assessed for the presence of nontrauma fracture codes after BMD testing. The effect of vertebral exclusions by expert physicians and several automated methods on diagnosis and prediction of incident fractures was compared.

RESULTS

Vertebral exclusions were reported by physicians in over one quarter of the scans (31% of women and 29% of men). All methods of vertebral exclusion significantly decreased the mean spine T-score and increased the proportion of women designated as osteoporotic. kappa values and ROC area under the curve (AUC) for physician-computer agreement in the identification of abnormal scans indicated fair to moderate agreement in both women and men. Compared with no vertebral exclusions, a small increase in the hazard ratio and AUC for spine fracture and osteoporotic fracture prediction was seen after physician and computer exclusions. Compared with physician exclusions, AUC for prediction of osteoporotic fractures in men increased significantly with one computer algorithm (p = 0.004). The minimum vertebral T-score enhanced fracture prediction compared with no exclusions but approximately doubled the prevalence of osteoporotic categorization.

CONCLUSIONS

We observed fair to moderate agreement between the physician and computer methods for vertebral level exclusion. All methods of vertebral exclusion led to a small improvement in fracture prediction using the lumbar spine measurement. The automated algorithms performed at least as well as physicians when fractures were used as the endpoint.

Race/ethnicity and fracture risk assessment: an issue that is more than skin deep

The study of race/ethnicity in relation to health outcomes and health disparities is of great importance in medicine. This is as true in the field of osteoporosis as it is in others, and it comes into sharp focus when the question of population-specific reference data for bone densitometry arises. Race/ethnicity can be viewed as both an ecosocial construct and as a biomedical concept. Whether or not, and how, to use race/ethnicity in fracture assessment potentially places these two paradigms in opposition. In this article, some of the issues that need to be considered to develop a rational approach to reference data selection and a globally acceptable measure of fracture risk are reviewed. Race/ethnicity is often a proxy for other disease-related risk factors. Understanding fundamental risk factors goes beyond the language of race/ethnicity.