The social gradient of fractures at any skeletal site in men and women: data from the Geelong Osteoporosis Study Fracture Grid

Age-specific and age-standardized associations between socioeconomic status (SES) and fractures in adults showed a social gradient of fracture, irrespective of fracture site. Compared to the highest SES, males in the lowest SES group had a sixfold increased odds for any fracture, whilst females had a twofold increased odds.

INTRODUCTION

The effective identification of predisposing risk factors for fracture requires understanding any association with SES. These investigations should consider both sexes, span the adult age range and include any fractures. We investigated age- and sex-specific and age-standardized associations between SES and fractures at any skeletal site in Australians aged ≥ 50 years.

METHODS

Incident fractures that occurred 2006-2007 for adults aged ≥ 50 years were identified from radiological reports extracted for the Barwon Statistical Division, in south-eastern Australia. SES was determined by cross-referencing residential addresses with Australian Bureau of Statistics census data and then categorized in quintiles. We compared frequencies of observed vs. expected fractures for SES quintiles using χ (2) comparison, calculated age-specific fracture incidence across SES and compared age-standardized fracture rates in SES quintile 1 to quintile 5.

RESULTS

We identified 3943 incident fractures (69.4 % female); 47.4 % had occurred at major osteoporotic fracture (MOF) sites (hip, humerus, spine and forearm/wrist). Differences existed in observed vs. expected fractures across SES quintiles (p ≤ 0.001, sexes combined); all fractures showed an inverse association with SES (p ≤ 0.001, sexes combined). Compared to the highest SES quintile, individuals from the lowest SES quintile had between two to six times greater standardized fracture rates.

CONCLUSIONS

Disadvantaged men and women have an increased fracture incidence compared to their less disadvantaged counterparts. The large differences in fracture rates between SES groups warrant further research into designing appropriate, targeted interventions for those demographics at most risk.

Prior fracture as a risk factor for future fracture in an Australian cohort

SUMMARY

This study investigated the influence of prior fracture on the risk of subsequent fracture. There was a higher risk of subsequent fracture in both young and older adult age groups when Australian males or females had already sustained a prior fracture. Fracture prevention is important throughout life for both sexes.

INTRODUCTION

The purpose of this study was to determine the impact of prior fracture on the risk of subsequent fracture across the adult age range in Australian males and females.

METHODS

All-cause fractures were grouped into age categories for males and females enrolled in the Geelong Osteoporosis Study (Australia) using retrospective self-report data and prospective radiology-confirmed data. For all age categories, the relative risk (RR and 95% confidence interval (CI)) of subsequent fracture in a later age category was compared between those with prior fracture and those without.

RESULTS

For both sexes, childhood fracture increased the risk of subsequent fracture in adolescence (males: RR 21.7; 95% CI 16.0, 27.4; females: RR 8.1; 3.5, 12.8). Males with adolescent fracture had increased risk of subsequent fracture in early adulthood (RR 11.5; 5.7, 17.3) and mid-adulthood (RR 13.0; 6.3, 19.7). Additionally, males with young adulthood or mid-adulthood fracture had increased risk of subsequent fracture in the following age group (RR 11.2; 4.4, 17.9, and RR 6.2; 0.8, 11.7, respectively). Mid-adult fractures increased the risk of subsequent fracture in older adulthood (RR 6.2; 0.8, 11.7). Females with childhood or adolescent fracture had an increased risk of fracture in young adulthood (RR 4.3; 0.7, 7.9, and RR 10.5; 4.4, 16.6), and prior fracture in older adult life increased the risk of subsequent fracture in old age (RR 14.9; 6.4. 23.3).

CONCLUSIONS

Fracture prevention strategies may be more effective if attention is directed towards individuals with prior fracture at any age as they have a higher likelihood of sustaining a subsequent fracture later in life.

Is there an interaction between socioeconomic status and FRAX 10-year fracture probability determined with and without bone density measures? Data from the Geelong Osteoporosis Study of female cohort

FRAX(©) evaluates 10-year fracture probabilities and can be calculated with and without bone mineral density (BMD). Low socioeconomic status (SES) may affect BMD, and is associated with increased fracture risk. Clinical risk factors differ by SES; however, it is unknown whether aninteraction exists between SES and FRAX determined with and without the BMD. From the Geelong Osteoporosis Study, we drew 819 females aged ≥50 years. Clinical data were collected during 1993-1997. SES was determined by cross-referencing residential addresses with Australian Bureau of Statistics census data and categorized in quintiles. BMD was measured by dual energy X-ray absorptiometry at the same time as other clinical data were collected. Ten-year fracture probabilities were calculated using FRAX (Australia). Using multivariable regression analyses, we examined whether interactions existed between SES and 10-year probability for hip and any major osteoporotic fracture (MOF) defined by use of FRAX with and without BMD. We observed a trend for a SES * FRAX(no-BMD) interaction term for 10-year hip fracture probability (p = 0.09); however, not for MOF (p = 0.42). In women without prior fracture (n = 518), we observed a significant SES * FRAX(no-BMD) interaction term for hip fracture (p = 0.03) and MOF (p = 0.04). SES does not appear to have an interaction with 10-year fracture probabilities determined by FRAX with and without BMD in women with previous fracture; however, it does appear to exist for those without previous fracture.

Sex- and age-specific associations between income and incident major osteoporotic fractures in Canadian men and women: a population-based analysis

We investigated sex- and age-specific associations between income and fractures at the hip, humerus, spine, and forearm in adults aged ≥50 years. Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women.

INTRODUCTION

Associations between income and hip fractures are contested, even less is known about other fracture sites. We investigated sex- and age-specific associations between income and major osteoporotic fractures (MOF) at the hip, humerus, spine, and forearm.

METHODS

Incident fractures were identified from administrative health data for adults aged ≥50 years in Manitoba, Canada, 2000-2007. Mean neighborhood (postal code area) annual household incomes were extracted from 2006 census files and categorized into quintiles. We calculated age-adjusted and age-specific sex-stratified fracture incidence across income quintiles. We estimated relative risks (RR) and 95% CI for income quintile 1 (Q1, lowest income) vs. income quintile 5 (Q5) and tested the linear trend across quintiles.

RESULTS

We identified 15,094 incident fractures (4736 hip, 3012 humerus, 1979 spine, and 5367 forearm) in 2718 men and 6786 women. For males, the RR of fracture for the lowest vs. highest income quintile was 1.63 (95% CI 1.42-1.87) and the negative trend was statistically significant (p < 0.0001); individual skeletal sites showed similar associations. For females, the RR of fracture for the lowest vs. highest income quintile was 1.14 (95% CI 1.01-1.28), with a statistically significant negative trend (p = 0.0291); however, the only skeletal site associated with income in women was the forearm (Q1 vs. Q5 RR 1.09, 95% CI 1.01-1.28).

CONCLUSIONS

Compared to men with the highest income, men with the lowest income had an increased fracture risk at all skeletal sites. These associations were attenuated in women. For men, these effect sizes seem large enough to warrant public health concern.

The association between critical illness and changes in bone turnover in adults: a systematic review

SUMMARY

Critical illness may lead to altered bone turnover and associated adverse health outcomes. This systematic review found moderate evidence for a positive association between critical illness and increased bone turnover. Prospective cohort studies that identify the extent and risk factors for critical illness related bone loss are required.

INTRODUCTION

Intensive care patients face health issues that extend beyond their critical illness and result in significant morbidity and mortality. Critical illness may result in altered bone turnover due to associated immobilisation, inflammation, exposure to medications that effect bone and calcium metabolism, and endocrine dysfunction. The aim of this study was to synthesise the existing evidence for altered bone turnover in adults admitted to intensive care.

METHODS

A literature search using MEDLINE and EMBASE was performed from 1965 to March 2013. Reviewed studies investigated the relationship between critical illness and evidence of altered bone turnover (bone turnover markers, bone mineral density, or fracture). Studies were rated upon their methodological quality, and a best-evidence synthesis was used to summarise the results.

RESULTS

Four cohort and seven case-control studies were identified for inclusion, of which five studies were rated as being of higher methodological quality. Ten of the studies measured bone turnover markers, and one study fracture rate. Findings were consistent across studies, and best-evidence analysis resulted in a conclusion that moderate evidence exists for an association between critical illness requiring admission to intensive care and altered bone turnover.

CONCLUSION

A positive association between critical illness requiring intensive care admission and bone turnover exists, although data are limited, and the risk factors and the nature of the relationship are not yet understood. Prospective cohort studies that identify risk factors and extent of critical illness related bone turnover changes are required.

Fracture risk among older men: osteopenia and osteoporosis defined using cut-points derived from female versus male reference data

SUMMARY

We explored the effect of using male and female reference data in a male sample to categorise areal bone mineral density (BMD). Using male reference data, a large proportion of fractures arose from osteopenia, whereas using female reference data shifted the fracture burden into normal BMD.

INTRODUCTION

The purpose of this study was to describe fracture risk associated with osteopenia and osteoporosis in older men, defined by areal BMD and using cut-points derived from male and female reference data.

METHODS

As part of the Geelong Osteoporosis Study, we followed 619 men aged 60-93 years after BMD assessments (performed 2001-2006) until 2010, fracture, death or emigration. Post-baseline fractures were radiologically confirmed, and proportions of fractures in each BMD category were age-standardised to national profiles.

RESULTS

Based on World Health Organization criteria, and using male reference data, 207 men had normal BMD at the femoral neck, 357 were osteopenic and 55 were osteoporotic. Using female reference data, corresponding numbers were 361, 227 and 31. During the study, 130 men died, 15 emigrated and 63 sustained at least one fracture. Using male reference data, most (86.5 %) of the fractures occurred in men without osteoporosis on BMD criteria (18.4 % normal BMD, 68.1 % osteopenia). The pattern differed when female reference data were used; while most fractures arose from men without osteoporosis (88.2 %), the burden shifted from those with osteopenia (34.8 %) to those with normal BMD (53.4 %).

CONCLUSIONS

Decreasing BMD categories defined increasing risk of fracture. Although men with osteoporotic BMD were at greatest risk, they made a relatively small contribution to the total burden of fractures. Using male reference data, two-thirds of the fractures arose from men with osteopenia. However, using female reference data, approximately half of the fractures arose from those with normal BMD. Using female reference data to define osteoporosis in men does not appear to be the optimal approach.

Does obesity affect knee cartilage? A systematic review of magnetic resonance imaging data

There is increasing evidence for the effect of obesity on knee osteoarthritis (OA), although the association between obesity, particularly body composition, and knee osteoarthritis, using magnetic resonance imaging (MRI) to examine knee structure, has not been examined. We systematically evaluated the evidence for the relationship between obesity and knee cartilage assessed by MRI. We performed an electronic search of MEDLINE and EMBASE up to December 2012. Included studies investigated the association between obesity and the development and/or progression of knee cartilage changes using MRI. The studies were ranked according to their methodological score and best-evidence synthesis was performed to summarize the results Twenty-two studies were identified for inclusion, of which 7 were cross-sectional, 13 were longitudinal and 2 had both cross-sectional and longitudinal components. Seven cross-sectional and eight longitudinal studies were of high quality. Best-evidence synthesis showed consistent, yet limited evidence for a detrimental effect of body mass index (BMI) and fat mass on knee cartilage. This review identified a consistent detrimental effect of obesity, particularly related to elevated BMI and fat mass on cartilage defects. The strength of evidence was limited by the paucity of high-quality cohort studies examining this question. By further examining the mechanisms for these different effects, new strategies can be developed to prevent and treat knee OA.

FRAX provides robust fracture prediction regardless of socioeconomic status

We investigated the fracture risk assessment tool (FRAX) Canada calibration and discrimination according to income quintile in 51,327 Canadian women, with and without a competing mortality framework. Our data show that, under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of socioeconomic status (SES).

INTRODUCTION

FRAX® predicts 10-year fracture risk. Social factors may independently affect fracture risk. We investigated FRAX calibration and discrimination according to SES.

METHODS

Women aged ≥50 years with baseline femoral neck bone mineral density (BMD) were identified from the Manitoba Bone Density Program, Canada (n = 51,327), 1996-2011. Mean household income, extracted from 2006 census files, was categorized into quintiles. Ten-year fracture probabilities were calculated using FRAX Canada. Incident non-traumatic fractures were studied in relation to income quintile in adjusted Cox proportional hazards models. We compared observed versus predicted fractures with and without a competing mortality framework.

RESULTS

During mean 6.2 ± 3.7 years of follow up, there were 6,392 deaths, 3,723 women with ≥1 major osteoporotic fracture (MOF), and 1,027 with hip fractures. Lower income was associated with higher risk for death, MOF, and hip fracture in adjusted models (all p < 0.005). More women in income quintile 1 (lowest) versus quintile 5 experienced death (19 vs. 8%), MOF (10 vs. 6%), or hip fracture (3.0 vs. 1.3 %) (all p ≤ 0.001). Adjustment for competing mortality mitigated the effect of SES on FRAX calibration, and good calibration was observed. FRAX provided good fracture discrimination for MOF and hip fracture within each income quintile (all p < 0.001). Area under the curve was slightly lower for income quintiles 1 versus 5 for FRAX with BMD to predict MOF (0.68, 95% CI 0.66-0.70 vs. 0.71, 95% CI 0.69-0.74) and hip fracture (0.79, 95% CI 0.76-0.81 vs. 0.87, 95% CI 0.84-0.89).

CONCLUSION

Increased fracture risk in individuals of lower income is offset by increased mortality. Under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of SES.

Is lower income associated with an increased likelihood of qualification for treatment for osteoporosis in Canadian women?

We examined whether low income was associated with an increased likelihood of treatment qualification for osteoporotic fracture probability determined by Canada FRAX in women aged ≥50 years. A significant negative linear association was observed between income and treatment qualification when FRAX included bone mineral density (BMD), which may have implications for clinical practice.

INTRODUCTION

Lower income has been associated with increased fracture risk. We examined whether lower income in women was associated with an increased likelihood of treatment qualification determined by Canada FRAX®.

METHODS

We calculated 10-year FRAX probabilities in 51,327 Canadian women aged ≥50 years undergoing baseline BMD measured by dual energy x-ray absorptiometry 1996-2001. FRAX probabilities for hip fracture ≥3% or major osteoporotic fracture (MOF) ≥20 % were used to define treatment qualification. Mean household income from Canada Census 2006 public use files was used to categorize the population into quintiles. Logistic regression analyses were used to model the association between income and treatment qualification.

RESULTS

Percentages of women who qualified for treatment based upon high hip fracture probability increased linearly with declining income quintile (all p trend <0.001), but this was partially explained by older age among lower income quintiles (p trend <0.001). Compared to the highest income quintile, women in the lowest income quintile had a greater likelihood of treatment qualification based upon high hip fracture probability determined with BMD (age-adjusted odds ratio [OR], 1.34; 95% confidence intervals (CI), 1.23-1.47) or high MOF fracture probability determined with BMD (age-adjusted OR, 1.31; 95% CI, 1.18-1.46). Differences were nonsignificant when FRAX was determined without BMD, implying that BMD differences may be the primary explanatory factor.

CONCLUSIONS

FRAX determined with BMD identifies a larger proportion of lower income women as qualifying for treatment than higher income women.

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.

Direct comparison of eight national FRAX® tools for fracture prediction and treatment qualification in Canadian women

SUMMARY

We compared the calibration of FRAX tools from Canada, the US (white), UK, Sweden, France, Australia, New Zealand, and China when used to assess fracture risk in 36,730 Canadian women. Our data underscores the importance of applying country-specific FRAX tools that are based upon high-quality national fracture epidemiology.

PURPOSE

A FRAX® model for Canada was constructed for prediction of hip fracture and major osteoporotic fracture (MOF) using national hip fracture and mortality data. We examined the calibration of this model in Canadian women and compared it with seven other FRAX tools.

METHODS

In women aged ≥50 years with baseline bone mineral density (BMD) measures identified from the Manitoba Bone Density Program, Canada (n = 36,730), 10-year fracture probabilities were calculated with and without BMD using selected country-specific FRAX tools. FRAX risk estimates were compared with observed fractures ≤10 years (506 hip, 2,380 MOF). Ten-year fracture risk was compared with predicted probabilities, and proportions exceeding specific treatment thresholds contrasted.

RESULTS

For hip fracture prediction, good calibration was observed for FRAX Canada and most other country-specific FRAX tools, excepting Sweden (risk overestimated) and China (risk underestimated). For MOF prediction, greater between-country differences were seen; FRAX Sweden and FRAX China showed the largest over- and underestimation in this Canadian population. Relative to treatment qualification based upon FRAX Canada, treatment of high-hip fracture probability (≥3%) was greater by FRAX Sweden (ratio 1.41 without and 1.55 with BMD), and markedly less by FRAX China (ratio 0.09 without and 0.11 with BMD). Greater between-country differences were observed for treatment of high MOF (≥20%); FRAX Sweden again greatly increased (ratio 1.76 without and 1.83 with BMD), and FRAX China severely reduced treatment qualification (ratio 0.00 without and 0.01 with BMD).

CONCLUSIONS

The use of country-specific FRAX tools, accurately calibrated to the target population, is essential. Relatively small calibration differences can have large effects on high-risk categorization and treatment qualification.

Social disadvantage, bone mineral density and vertebral wedge deformities in the Tasmanian Older Adult Cohort

The relationship between social disadvantage and bone mineral density (BMD) is complex and remains unclear; furthermore, little is known of the relationship with vertebral deformities. We observed social disadvantage to be associated with BMD for females, independent of body mass index (BMI). A lower prevalence of vertebral deformities was observed for disadvantaged males.

INTRODUCTION

The relationship between social disadvantage and BMD appears complex and remains unclear, and little is known about the association between social disadvantage and vertebral wedge deformities. We examined the relationship between social disadvantage, BMD and wedge deformities in older adults from the Tasmanian Older Adult Cohort.

METHODS

BMD and wedge deformities were measured by dual-energy X-ray absorptiometry and associations with extreme social disadvantage was examined in 1,074 randomly recruited population-based adults (51 % female). Socioeconomic status was assessed by Socio-economic Indexes for Areas values derived from residential addresses using Australian Bureau of Statistics 2001 census data. Lifestyle variables were collected by self-report. Regression models were adjusted for age, BMI, dietary calcium, serum vitamin D (25(OH)D), smoking, alcohol, physical inactivity, calcium/vitamin D supplements, glucocorticoids and hormone therapy (females only).

RESULTS

Compared with other males, socially disadvantaged males were older (65.9 years versus 61.9 years, p = 0.008) and consumed lower dietary calcium and alcohol (both p ≤ 0.03). Socially disadvantaged females had greater BMI (29.9 ± 5.9 versus 27.6 ± 5.3, p = 0.002) and consumed less alcohol (p = 0.003) compared with other females. Socially disadvantaged males had fewer wedge deformities compared with other males (33.3 % versus 45.4 %, p = 0.05). After adjustment, social disadvantage was negatively associated with hip BMD for females (p = 0.02), but not for males (p = 0.70), and showed a trend for fewer wedge deformities for males (p = 0.06) but no association for females (p = 0.85).

CONCLUSIONS

Social disadvantage appears to be associated with BMD for females, independent of BMI and other osteoporosis risk factors. A lower prevalence of vertebral deformities was observed for males of extreme social disadvantage. Further research is required to elucidate potential mechanisms for these associations.

Calcaneal ultrasound reference ranges for Australian men and women: the Geelong Osteoporosis Study

Heel ultrasound is a more portable modality for assessing fracture risk than dual-energy X-ray absorptiometry and does not use ionising radiation. Fracture risk assessment requires appropriate reference data to enable comparisons. This study reports the first heel ultrasound reference ranges for the Australian population.

INTRODUCTION

This study aimed to develop calcaneal (heel) ultrasound reference ranges for the Australian adult population using a population-based random sample.

METHODS

Men and women aged≥20 years were randomly selected from the Barwon Statistical Division in 2001-2006 and 1993-1997, respectively, using the electoral roll. Broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (SI) were measured at the heel using a Lunar Achilles Ultrasonometer. Gender-specific means and standard deviations for BUA, SOS and SI were calculated for the entire sample (men 20-93 years, n=1,104; women 20-92 years, n=914) and for participants aged 20-29 years (men, n=157; women, n=151). Associations between ultrasound measures and age were examined using linear regression.

RESULTS

For men, mean±standard deviation BUA, SOS and SI were 118.7±15.8 dB/MHz, 1,577.0±43.7 m/s and 100.5±20.7, respectively; values for women were consistently lower (111.0±16.4 dB/MHz, P<0.001; 1,571.0±39.0 m/s, P=0.001; and 93.7±20.3, P<0.001, respectively). BUA was higher in young men compared with young women (124.5±14.4 vs 121.0±15.1 dB/MHz), but SOS (1,590.1±43.1 vs 1,592.5±35.0 m/s) and SI (108.0±19.9 vs 106.3±17.7) were not. The relationships between age and each ultrasound measure were linear and negative across the age range in men; associations were also negative in women but non-linear.

CONCLUSION

These data provide reference standards to facilitate the assessment of fracture risk in an Australian population using heel ultrasound.

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.

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 mineral density is cross sectionally associated with cartilage volume in healthy, asymptomatic adult females: Geelong Osteoporosis Study

INTRODUCTION

The association between osteoporosis and osteoarthritis (OA) is controversial. Although previous studies have shown total body, lower limb, spinal and knee BMD and knee cartilage volume to be positively associated, the relationship between other distant site-specific measures of BMD and other knee structures is unknown. The aim of this study was to determine the associations between BMD at eight skeletal sites, and knee structure in asymptomatic young to middle-aged females without any clinical signs of OA.

METHODS

One hundred and sixty healthy, asymptomatic females (29-50 yr) underwent magnetic resonance imaging of the knee. BMD was measured at the spine, hip, total body and forearm by dual energy X-ray absorptiometry, and at the calcaneus by quantitative ultrasound. BMD was tested for an association with cartilage volume, defects, and bone marrow lesions (BMLs).

RESULTS

Medial cartilage volume was positively associated with BMD at the spine, total body, femoral neck, and Ward's triangle (all p<0.05), with non-significant associations in the same direction at the trochanter (p=0.07). Findings in the lateral compartment were similar. The presence of medial cartilage knee defects were also associated with BMD at the spine; defects in the lateral compartment were associated with BMD at the forearm (both p=0.05). BMD was not associated with the presence of BMLs. No associations were observed with calcaneus BMD.

CONCLUSIONS

Site-specific BMD is associated with cartilage volume at the knee in asymptomatic young to middle-aged adults, with the direction and effects trending in the same direction. The magnitude of changes correlates with clinically relevant changes. QUS defined calcaneus BMD, showed no associations with knee structure. Although systemic factors may underlie the association between knee cartilage volume and axial/lower limb BMD, these data suggest that common local, possibly biomechanical factors may also play a role.

Incident hip fracture and social disadvantage in an Australian population aged 50 years or greater

AIMS

There is an inverse association between socioeconomic status (SES) and most causes of morbidity. Hip fractures pose a significant public health burden on society. However, the association between quintiles of area-based SES and incident hip fractures has not been examined in Australia. Using a comprehensive register of hip fractures for the entire Barwon Statistical Division (BSD), we assessed the association between area-based SES and incident hip fractures over a two-year period in residents aged ≥ 50years.

METHODS

Incident hip fractures were identified using a computerized keyword search of all radiological reports from all the radiological centers serving the BSD. Pathological fractures were excluded. SES was determined by cross-referencing residential addresses with Australian Bureau of Statistics census data and categorized in quintiles based upon the BSD reference range. Homogeneity of population at risk in each SES quintile was tested using chi square comparison. Hip fractures in each quintile and within each age strata for the entire BSD region were defined as rates per 1000 person-years.

RESULTS

During 2006-2007, there were 495 hip fractures (336 female). An inverse pattern of association was observed between SES and hip fracture incidence, with a peak in fracture numbers observed in the second quintile of SES, with differences between SES quintiles observed for both females (p = 0.005) and males (p = 0.007).

CONCLUSION

The association between incident hip fractures and quintiles of area-based SES provides evidence that those of greater social disadvantage should be a specific target population for intervention to reduce the burden of hip fracture within Australia.

Association between socioeconomic status and bone mineral density in adults: a systematic review

For most causes of mortality and morbidity, a socioeconomic gradient exists; however, this systematic review identified limited evidence for the role of education on bone mineral density (BMD). Further research is required to build upon the current paucity of data examining influences of socioeconomic status (SES) on BMD, especially in men.

INTRODUCTION

For most causes of mortality and morbidity, a socioeconomic gradient exists, although little is understood of the relationship between BMD and SES. We systematically evaluated evidence of SES as a risk factor for low BMD at the clinically relevant sites of hip and spine in adults.

METHODS

We conducted a computer-aided search of Medline, EMBASE, CINAHL, and PsychINFO from January 1, 1966 until December 31, 2008. Reviewed studies investigated the relationship between SES parameters of income, education, and occupation, and the level of BMD. Studies were rated based on their methodological quality, and a best-evidence synthesis was used to summarise the results.

RESULTS

One case-control and seven cross-sectional studies were identified for inclusion, of which four cross-sectional studies were high-quality. Best-evidence analysis identified consistent, yet limited, evidence for a positive association between educational attainment and BMD in women. No evidence was available regarding an association between income or occupation and BMD in either gender, or education and BMD in men.

CONCLUSIONS

Limited good quality evidence exists for the role that education level may play in BMD levels. Cohort studies are required to examine the relationship between individual SES parameters and BMD in order to identify potential intervention targets.

Anxiety is more common in children with asthma

OBJECTIVE

There are a variety of reasons why there may be an association between asthma and anxiety in children. Research into the relation between asthma and anxiety has been limited by the sole use of parent-reported or self-reported asthma symptoms to define asthma status. The objective of this study was to determine if children with physician-defined asthma are more likely to suffer anxiety than children without asthma.

DESIGN

A population-based, cross-sectional assessment, of self-reported anxiety symptoms.

SETTING AND PARTICIPANTS

Children aged 5-13 years from Barwon region of Victoria, Australia. Asthma status was determined by review with a paediatrician. Controls were a sample of children without asthma symptoms (matched for age, gender and school).

OUTCOME MEASURE

The Spence Children's Anxiety Scale (SCAS) written questionnaire. The authors compared the mean SCAS score, and the proportion of children with an SCAS score in the clinical range, between the groups.

RESULTS

Questionnaires were issued to 205 children with asthma (158 returned, response rate 77%), and 410 controls (319 returned, response rate 78%). The SCAS scores were higher in asthmatics than controls (p<0.001); and were more likely to be in the clinical range (OR=2.5, 95% CI 1.1 to 5.8, p=0.036). There was no evidence that these associations could be explained by known confounding factors.

CONCLUSIONS

Children with asthma are substantially more likely to suffer anxiety than children without asthma. Future studies are required to determine the sequence of events that leads to this comorbidity, and to test strategies to prevent and treat anxiety among children with asthma.

Parent initiated prednisolone for acute asthma in children of school age: randomised controlled crossover trial

OBJECTIVE

To evaluate the efficacy of a short course of parent initiated oral prednisolone for acute asthma in children of school age.

DESIGN

Double blind, randomised, placebo controlled, crossover trial in which episodes of asthma, rather than participants, were randomised to treatment.

SETTING

The Barwon region of Victoria, Australia.

PARTICIPANTS

Children aged 5-12 years with a history of recurrent episodes of acute asthma.

INTERVENTION

A short course of parent initiated treatment with prednisolone (1 mg/kg a day) or placebo.

MAIN OUTCOME MEASURES

The primary outcome measure was the mean daytime symptom score over seven days. Secondary outcome measures were mean night time symptom score over seven days, use of health resources, and school absenteeism.

RESULTS

230 children were enrolled in the study. Over a three year period, 131 (57%) of the participants contributed a total of 308 episodes of asthma that required parent initiated treatment: 155 episodes were treated with parent initiated prednisolone and 153 with placebo. The mean daytime symptom score was 15% lower in episodes treated with prednisolone than in those treated with placebo (geometric mean ratio 0.85, 95% CI 0.74 to 0.98; P=0.023). Treatment with prednisolone was also associated with a 16% reduction in the night time symptom score (geometric mean ratio 0.84, 95% CI 0.70 to 1.00; P=0.050), a reduced risk of health resource use (odds ratio 0.54, 95% CI 0.34 to 0.86; P=0.010), and reduced school absenteeism (mean difference -0.4 days, 95% CI -0.8 to 0.0 days; P=0.045).

CONCLUSION

A short course of oral prednisolone initiated by parents when their child experiences an episode of acute asthma may reduce asthma symptoms, health resource use, and school absenteeism. However, the modest benefits of this strategy must be balanced against potential side effects of repeated short courses of an oral corticosteroid.

TRIAL REGISTRATION

ISRCTN 26232583.

The association between socioeconomic status and osteoporotic fracture in population-based adults: a systematic review

Although socioeconomic status (SES) is inversely related to most diseases, this systematic review showed a paucity of good quality data examining influences of SES on osteoporotic fracture to confirm this relationship. Further research is required to elucidate the issue and any underlying mechanisms as a necessary precursor to considering intervention implications.

INTRODUCTION

The association between socioeconomic status (SES) and musculoskeletal disease is little understood, despite there being an inverse relationship between SES and most causes of morbidity. We evaluated evidence of SES as a risk factor for osteoporotic fracture in population-based adults.

METHODS

Computer-aided search of Medline, EMBASE, CINAHL, and PsychINFO from January 1966 until November 2007 was conducted. Identified studies investigated the relationship between SES parameters of income, education, occupation, type of residence and marital status, and occurrence of osteoporotic fracture. A best-evidence synthesis was used to summarize the results.

RESULTS

Eleven studies were identified for inclusion, which suggested a lack of literature in the field. Best evidence analysis identified strong evidence for an association between being married/living with someone and reduced risk of osteoporotic fracture. Limited evidence exists of the relationship between occupation type or employment status and fracture, or for type of residence and fracture. Conflicting evidence exists for the relationship between osteoporotic fracture and level of income and education.

CONCLUSION

Limited good quality evidence exists of the role SES might play in osteoporotic fracture. Further research is required to identify whether a relationship exists, and to elucidate underlying mechanisms, as a necessary precursor to considering intervention implications.

The role of N-6-isopentenyl adenine in tumor cell growth

When cell extracts from Ehrlich ascites tumor cells were assayed for isopentenyl adenine content and correlation with cell growth stage by radioimmunoassay, concentrations of low statistical significance were obtained. High performance liquid chromatographic analysis of cell extracts showed undetectable levels of isopentenyl adenine or 8-hydroxy-isopentenyl adenine, a known metabolite. Thus these substances do not seem to be required for cell division in Ehrlich ascites tumor cells.