Variation In Hip Fracture Incidence Research Articles

Contribution of elevation and residential proximity to the coast in explaining geographic variations in hip fracture incidence. A Norwegian Epidemiologic Osteoporosis Studies (NOREPOS) study.

Norway is an elongated country extending north of the Arctic Circle with substantial coast-inland variation in topography and climate. Differences in hip fracture incidence between counties and a distinct seasonal variation have previously been shown. The aim of the current study was to explore these variations further by considering associations of height above sea level (elevation) and distance to the coast with hip fracture incidence. All patients with hip fractures admitted to Norwegian hospitals in the period 2009-2018 were included. Individual residential elevation and distance to the coast was calculated in Geographic Information Systems and combined with individual-level population data on all Norwegians 50years of age or older during the observation period, including hospital information on fractures. Age-standardized incidences rate and incidence rate ratios with 95% confidence intervals (IRR, 95% CI) according to elevation and coastal proximity were estimated. The associations were tested using Poisson models adjusting for sex, urban/rural location of residency, country of birth, and season of hip fracture occurrence. From 2009 to 2018, there were 85,776 first hip fractures. There was an increasing risk with higher residential elevation (above versus below mean) for women: IRR = 1.04, 95% CI: 1.02, 1.05), but not for men (IRR = 1.00, 95% CI: 0.97, 1.02). Incidence of hip fracture increased with distance from the coast. Women residing the farthest away from the coast (above versus below mean distance) had a higher age-adjusted incidence of hip fracture compared to those living closer to the coast (IRR = 1.04 (95% CI: 1.02, 1.06), whereas no association was found in men (IRR = 1.00 (95% CI: 1.00, 1.01). Combining elevation and distance to coast showed a higher incidence in women living at high elevation far from the coast compared with women living at low elevation near the coast (IRR = 1.07, 95% CI: 1.04, 1.10). A similar result was found in men but only for hip fractures occurring during March-May (IRR = 1.07, 95% CI: 1.00, 1.15). The previously shown patterns of county differences and seasonal variations were unchanged when considering geography. We found a somewhat higher incidence of hip fracture in inland residents living in areas of high elevation, as compared to those living in more coastal proximity; however, the geographic variation did not explain county and seasonal differences in fracture incidence in Norway. More in-depth analyses on temperature and climate factors may give further clues.

Geographic variations in hip fracture incidence in a high-risk country stretching into the Arctic: a NOREPOS study

SummaryThere are geographic variations in hip fracture incidence rates across Norway, with a lower incidence in the coastal areas of the southwest and in the Arctic north, contrary to what may be expected with regard to vitamin D exposure from sunlight. The regional differences have become smaller in recent years.IntroductionTo investigate geographic variation in hip fracture incidence within Norway and regional differences in time trends.MethodsAll hip fractures treated in Norwegian hospitals 2002–2013 were included, and demographic information was obtained from Statistics Norway. Age-standardized incidence rates were calculated separately for 19 counties. Incidence rate ratios with 95% confidence intervals for county differences and time trends were estimated using Poisson regression.ResultsAge-standardized number of hip fractures per 10,000 person-years varied between counties from 69 to 84 in women and from 34 to 41 in men. The highest rates were observed in the southeastern capital city of Oslo, while rates were low in the four northernmost counties. There was an east-west gradient, with lower incidence in the coastal southwest compared with the southeast. Women showed a statistically significant decline during 2002–2013 in almost all counties (up to 31%). In men, only a few counties showed a decline. In both genders, hip fracture rates at age 80 in the combined five counties with the highest rates were significantly higher than in the combined five counties with the lowest rates across the period, although the trends converged over time.ConclusionsIn Norway, the hip fracture incidence was lower in the north compared with the south. In addition, we observed an east-west gradient with the highest incidence in the southeast and lower incidence in the coastal southwest. While there has been an overall declining trend in hip fracture incidence over time, regional differences are still apparent.

Inequalities in hip fracture incidence are greatest in the North of England: regional analysis of the effects of social deprivation on hip fracture incidence across England.

Hip fracture risk varies by geography and by levels of deprivation. We examined the effect of local area-level deprivation on hip fracture incidence across nine regions in England, using 14 years of hospital data, to determine whether inequalities in hip fracture incidence rates vary across geographic regions in England. Sequential annual cross-sectional studies over 14 years. We used English Hospital Episodes Statistics (2001/02-2014/15) to identify hip fractures in adults aged 50+years and mid-year population estimates (2001-2014) from the Office for National Statistics. The Index of Multiple Deprivation was used to measure local area deprivation. We calculated age-standardised hip fracture incidence rates per 100,000 population, stratified by gender, geographic region, deprivation quintiles and time-period, using the 2001 English population as the reference population. Using Poisson regression, we calculated age-adjusted incidence rate ratios (IRRs) for hip fracture, stratified as above. Over 14 years, we identified 747,369 hospital admissions with an index hip fracture. Age-standardised hip fracture incidence was highest in the North East for both men and women. In North England (North East, North West and Yorkshire and the Humber), hip fracture incidence was relatively higher in more deprived areas, particularly among men: IRR most vs least deprived quintile 2.06 (95% confidence interval [CI] = 2.00-2.12) in men, 1.62 (95% CI 1.60-1.65) in women. A relationship, albeit less marked, between deprivation and hip fracture incidence was observed among men in the Midlands and South, but with no clear pattern among women. Regional variation in hip fracture incidence exists across England, with the greatest absolute burden of incident hip fractures observed in the North East for both men and women. Across local areas in North England, absolute and relative inequalities in hip fracture incidence were greater than in other regions. Our findings highlight the need for improved fracture prevention programmes that aim to reduce regional and social inequalities in hip fracture incidence.

Facility and State Variation in Hip Fracture in U.S. Nursing Home Residents.

To quantify the variation in hip fracture incidence across U.S. nursing home (NH) facilities and states and examine how hip fracture incidence varies according to facility- and state-level characteristics. Retrospective cohort using linked national Minimum Data Set assessments; Online Survey, Certification and Reporting records; and Medicare claims. U.S. NHs with 100 or more beds. Long-stay NH residents between May 1, 2007, and April 30, 2008, from 1,481 facilities and 46 U.S. states (N=201,892). Incident hip fractures were ascertained using Medicare Part A diagnostic codes. Each resident was followed for up to 2years. The mean adjusted incidence rate of hip fractures for all facilities was 3.13 (95% confidence interval (CI)=3.01-3.26) per 100 person-years (range 1.20, 95% CI=1.15-1.26 to 6.40, 95% CI=6.07-6.77). Facilities with the highest rates of hip fracture had greater percentages of residents taking psychoactive medications (top tertile 27.2%, bottom tertile 24.8%), and fewer nursing (top tertile 3.43, bottom tertile 3.53) and direct care (top tertile 3.22, bottom tertile 3.29) hours per day per resident. The combination of state and facility characteristics explained 6.7% of the variation in hip fracture, and resident characteristics explained 7.6%. Much of the variation in hip fracture incidence remained unexplained, although these findings indicate that potentially modifiable state and facility characteristics such as psychoactive drug prescribing and minimum staffing requirements could be addressed to help reduce the rate of hip fracture in U.S. NHs.

Hip fracture incidence and social deprivation: results from a French ecological study.

Regional variations in hip fracture (HF) incidence exist worldwide. Reasons for these variations remain unknown. As regional variations have also been observed for socioeconomic status, we analyzed the association between socioeconomic deprivation (SED) and HF incidence in France in 2008. From the French Hospital National Database, we selected all HF encoded as primary diagnosis in persons aged 30years and over. The recently published French version of the European Deprivation Index (EDI) was used for SED analysis, and an EDI score was measured for the year 2007 in each French local municipality. The EDI score was categorized in quintiles. Poisson regression was performed to examine the association between HF incidence and EDI adjusted for age and sex. The population attributable fraction (PAF) was measured to calculate the proportion of excess cases of HF associated with social affluence. In 2008, 83,538 HF were reported in France of which 59,143 were included in this study. Among them, 44,401 fractures occurred in women (75%) and 14,742 in men (25%). In both men and women, there was a decrease in the HF incidence with increasing SED index. In Poisson regression, the interaction of age class and sex was significant (p<0.0001) and the EDI in quintiles was significantly associated with the incidence of HF (p<0.0001). A higher number of people living in affluent residential areas corresponded to a higher risk of HF. The risk of HF is 2.42 times higher for those living in the most affluent group compared to those living in the most underprivileged group. The value of the PAF was calculated at 27.1%. Social disparities in HF incidence exist in France with the most deprived municipalities having the lowest incidence. Prior knowledge demonstrates the strong relationships between body weight and HF risk as well as between body weight and the SED. The link found in our study between EDI and HF incidence as well as regional and temporal variations in HF incidence may be partly due to the protective effect of increased body weight against HF.

Geographic Variation in Hip Fracture Among United States Long-Stay Nursing Home Residents

IntroductionDespite high rates of hip fracture among United States (US) nursing home (NH) residents, little is known about geographic variation in hip fracture incidence. We used nationally representative data to identify geographic variation in hip fracture among US NH residents. Design and settingRetrospective cohort study using Part A claims for a 100% of Medicare enrollees in 15,289 NHs linked to NH minimum data set and Online Survey, Certification, and Reporting databases. ParticipantsA total of 891,085 long-stay (continuous residence of ≥100 days) NH residents ≥65 years old. MeasurementsMedicare Part A claims documenting a hip fracture. Mean incidence rates of hip fracture for long-stay NH residents were calculated for each state and US Census Division from 2007 to 2010. ResultsThe age-, sex-, and race-adjusted incidence rate of hip fracture ranged from 1.49 hip fractures/100 person-years (Hawaii) to 3.60 hip fractures/100 person-years (New Mexico), with a mean of 2.38 (standard deviation 0.43) hip fractures/100 person-years. The mean incidence of hip fracture was 1.7-fold greater in the highest quintile than the lowest. ConclusionsWe observed modest US state and regional variation in hip fracture incidence among long-stay NH residents. Future studies should assess whether state policies or NH characteristics explain the variation.

Worldwide variation in hip fracture incidence weakly aligns with genetic divergence between populations.

This study investigates the influence of genetic differentiation in determining worldwide heterogeneity in osteoporosis-related hip fracture rates. The results indicate that global variation in fracture incidence exceeds that expected on the basis of random genetic variance. Worldwide, the incidence of osteoporotic hip fractures varies considerably. This variability is believed to relate mainly to non-genetic factors. It is conceivable, however, that genetic susceptibility indeed differs across populations. Here, we present the first quantitative assessment of the effects of genetic differentiation on global variability in hip fracture rates. We investigate the observed variance in publically reported age-standardized rates of hip fracture among 28 populations from around the world relative to the expected variance given the phylogenetic relatedness of these populations. The extent to which these variances are similar constitutes a "phylogenetic signal," which was measured using the K statistic. Population genetic divergence was calculated using a robust array of genome-wide single nucleotide polymorphisms. While phylogenetic signal is maximized when K > 1, a K value of only 0.103 was detected in the combined-sex fracture rate pattern across the 28 populations, indicating that fracture rates vary more than expected based on phylogenetic relationships. When fracture rates for the sexes were analyzed separately, the degree of phylogenetic signal was also found to be small (females: K = 0.102; males: K = 0.081). The lack of a strong phylogenetic signal underscores the importance of factors other than stochastic genetic diversity in shaping worldwide heterogeneity in hip fracture incidence.

Impact of comorbidity, age, and gender on seasonal variation in hip fracture incidence. A NOREPOS study.

Based on a total of 136,140 hip fractures, we found a distinct seasonal variation in hip fracture incidence present in subgroups defined by age, gender, and comorbidity. The seasonal variation was most pronounced in the youngest and the healthiest patients. The purpose of this study was to examine the possible seasonal variation in hip fracture incidence in Norway by comorbidity, age, and gender. Data were retrieved from the NOREPOS Hip Fracture Database containing all hip fractures in Norway during the time period 1994-2008. Hip fractures were identified by computerized hospital discharge diagnoses. Charlson comorbidity index was calculated based on additional diagnoses and categorized (0, 1, and ≥2). Summer was defined as June, July, and August and winter as December, January, and February. Incidence rate ratios for hip fracture according to season were calculated by negative binomial models. In patients aged 50-103 years, 136,140 eligible fractures were identified (72.5 % women). The relative risk of hip fracture in winter versus summer was 1.40 (95 % confidence interval (CI) 1.36-1.45) in men and 1.26 (95 % CI 1.23-1.28) in women. June had the lowest number of fractures in both genders. We found seasonal variation in all subgroups by age and gender, although least pronounced in patients >79 years. There was a significant interaction between season and comorbidity (p = 0.022). When comparing winter to summer, we found relative risks of 1.40 (95 % CI 1.31-1.50) in patients with Charlson index = 0, 1.29 (95 % CI 1.19-1.40) in patients with Charlson index = 1, and 1.18 (95 % CI 1.08-1.28) in patients with Charlson index ≥2. There was a distinct seasonal variation in hip fracture incidence, present in all subgroups of gender, age, or comorbidity. This variation should be accounted for when planning health-care services.

Regional Variation in Hip Fracture Incidence Among Japanese Hemodialysis Patients

Hip fracture incidence in Japanese hemodialysis patients is five-fold higher than in the general population, although the mechanisms underlying this difference are not fully understood. Substantial regional variation exists in hip fracture incidence in the general Japanese population, despite a uniform health care and insurance system and lack of ethnic and racial variation. In this study, we determined whether the regional variation seen in the general population also applies to hemodialysis patients in Japan. Standardized incidence ratios were calculated for each regional district, and regional variations of hip fracture incidence among hemodialysis patients were evaluated using data obtained from the Japanese Society for Dialysis Therapy registry (data collected from December 2007 to December 2008). Standardized hip fracture incidence ratios across the districts ranged from 0.71 to 1.29 for male and 0.49 to 1.36 for female hemodialysis patients. Incidence ratios tended to be higher in western Japan and lower in eastern Japan, suggesting that regional variation also exists among hemodialysis patients. Our findings suggest that common risk factors for hip fracture may be shared among the general population and hemodialysis patients. Further research aimed at identifying factors, including those associated with regional variation, may help decrease hip fracture incidence in both the general population and hemodialysis patients in Japan.

Variations in solar UVB doses and serum 25-hydroxyvitamin D concentrations may explain the worldwide variation in hip fracture incidence

Variations in solar UVB doses and serum 25-hydroxyvitamin D concentrations may explain the worldwide variation in hip fracture incidence

Variations in latitude may or may not explain the worldwide variation in hip fracture incidence

Variations in latitude may or may not explain the worldwide variation in hip fracture incidence

Incidence and seasonal variation in hip fracture incidence among elderly women in Norway. The HUNT Study

There is a substantial variation in hip fracture incidence between populations. The Scandinavian countries have the highest incidence of hip fractures worldwide, and latitude and seasonal variation have been discussed as possible reasons for the high fracture incidences. The purpose of this study was to investigate time dependent and seasonal variation of hip fractures in a population based cohort of women aged 65+ residing in a rural county in Norway and followed for 9.3 years.Information at baseline was collected as part of The Nord-Trøndelag Health Study (HUNT) during 1995–97, and 8362 women with no previous hip fracture and with a mean age of 74.3 years were included in the study. All hip fractures occurring after inclusion in the health study were registered (mean follow-up: 9.3 years) by medical journals and x-ray reports. A total of 5661 of the women had their forearm bone mineral density (BMD) measured by single energy x-ray bone densitometers (SXA) as part of HUNT.In total, 782 women sustained a first hip fracture during follow-up, and the overall hip fracture incidence rate per 1000 person-years was 13.1 (95 % CI: 12.2-14.1). The hip fracture incidence increased exponentially by age from 2.1 (95% CI: 1.2-3.8) in the age group 65–69 years to 49.7 (95% CI: 41.2–59.8) among the women aged 90+, respectively. In age-stratified analyses no changes in the incidence of hip fractures were observed during the nine years of follow up. The occurrence of fractures varied by season of the year, characterized by higher fracture rates during the winter months. In conclusion, the hip fracture rates in this population of elderly women are highest in the winter months. There was, however, no indication of an increasing hip fracture incidence in this rural area. Compared to similar studies from more urban areas in Norway, the hip fracture rates in this population seem somewhat lower.

Geographic variation of bone mineral density and selected risk factors for prediction of incident fracture among Canadians 50 and older

Background Striking geographic variation in the incidence of osteoporotic fracture has been shown in national and international studies. The contributing risk factors for this variation are not fully understood. Objective To determine the geographic variation of bone mineral density (BMD) values, prevalent low-trauma fracture, prior falls, and vertebral deformity and to determine how this variation is related to the geographic variation of incident low-trauma fracture. Methods We studied incident fracture among 2484 men and 6093 women ages 50 and older from CaMos, a randomly-selected population-based longitudinal cohort recruited from within 50 kilometers of nine cities across Canada. Analyses included up to an eight-year follow-up. Results Estimates of fracture incidence are all age-standardized and given per 1000 person-years and CI denotes confidence interval. Among men, the lowest incidence of low-trauma fracture was 3.2 (95% CI: 1.1–7.5) in Quebec and the highest was 11.9 (95% CI: 7.1–18.6) in Calgary, compared with an overall incidence of 7.2 (95% CI: 5.8–8.7). Among women, the lowest incidence of low-trauma fracture was 11.5 (95% CI: 8.5–15.1) in Halifax and the highest was 18.5 (95% CI: 14.6–23.3) in Calgary, compared with an overall incidence of 15.3 (95% CI: 14.1–16.7). The regional variation in low-trauma fractures was similar to variation in hip fracture incidence among women (Pearson correlation, r = 0.46 to 0.76) but not men ( r = − 0.06 to 0.05). We noted significant geographic variation in the prevalence of low BMD, as defined by BMD T-score ≤ − 2.5, however this variation was not directly related to low-trauma fractures or other risk factors. Furthermore, a model including age, BMD, falls, vertebral deformity, and prior clinical fracture was a good predictor of geographic variation of low-trauma fracture incidence in both men ( r = 0.66) and women ( r = 0.84). Conclusions For both men and women, the burden of low-trauma fracture is not related to the prevalence of osteoporosis as defined by BMD, but is related to a more comprehensive assessment of fracture risk including the following: age, BMD, falls, prior fracture, and vertebral deformity.

International variations in hip fracture probabilities: implications for risk assessment.

It is recommended that intervention thresholds should be based on absolute fracture risk, but there is a large variation in hip fracture incidence from different regions of the world. The aim of this study was to examine heterogeneity of hip fracture probability in different regions from recent estimates of hip fracture incidence and mortality to adjust intervention thresholds. Ten-year probabilities of hip fracture were computed in men and women at 10-year intervals from the age of 50 years and lifetime risks at the age of 50 years from the hazard functions of hip fracture and death. Lifetime risk at the age of 50 years varied from 1% in women from Turkey to 28.5% in women from Sweden. High lifetime risks in women were associated with high lifetime risks in men (r = 0.83). There also were significant correlations of 10-year risk at any age between men and women. Ten-year probability was standardized to that of men and women from Sweden (set at 1.0). There was a 15-fold range in 10-year probability from 1.24 in Norway to 0.08 in Chile. Countries were categorized by 10-year probabilities comprising very high risk (Norway, Iceland, Sweden, Denmark, and the United States), high risk (China [Taiwan [TW]], Germany, Switzerland, Finland, Greece, Canada, The Netherlands, Hungary, Singapore, Italy, United Kingdom, Kuwait, Australia, and Portugal), medium risk (China [Hong Kong [HK]], France, Japan, Spain, Argentina, and China), and low risk (Turkey, Korea, Venezuela, and Chile). The categorization of hip fracture probabilities can be used to adjust intervention thresholds based on age, sex, and relative risk from a reference population such as Sweden.

Worldwide incidence of hip fracture in elderly women: relation to consumption of animal and vegetable foods.

Hip fracture, a major health problem in elderly persons, varies in incidence among the populations of different countries and is directly related to animal protein intake, a finding that suggests that bone integrity is compromised by endogenous acid production consequent to the metabolism of animal proteins. If that is so, vegetable foods might provide a countervailing effect, because they are a rich source of base (bicarbonate) in the form of metabolizable organic anions, which can neutralize protein-derived acid and supply substrate (carbonate) for bone formation. We analyzed reported hip fracture incidence (HFI) data among countries (N = 33) in women aged 50 years and older, in relation to corresponding country-specific data on per capita consumption of vegetable and animal foods as reported by the United Nations Food and Agriculture Organization. HFI varied directly with total (r = +.67, p < .001) and animal (r = +.82, p < .001) protein intake and inversely with vegetable protein intake (r = .37, p < .04). The countries in the lowest tertile of HFI (n = 11) had the lowest animal protein consumption, and invariably, vegetable protein (VP) consumption exceeded the country's corresponding intake of animal protein (AP): VP/AP > 1.0. By contrast, among the countries in the highest tertile of HFI, animal protein intake exceeded vegetable protein intake in nearly every case (10 of 11 countries). Among all countries, HFI correlated inversely and exponentially with the ratio of vegetable/animal protein intake (r = -.84, p < .001) and accounted for 70% of the total variation in HFI. Adjusted for total protein intake, vegetable food consumption was an independent negative predictor of HFI. All findings were similar for the subset of 23 countries whose populations are predominantly Caucasian. The findings suggest that the critical determinant of hip fracture risk in relation to the acid-base effects of diet is the net load of acid in the diet, when the intake of both acid and base precursors is considered. Moderation of animal food consumption and an increased ratio of vegetable/animal food consumption may confer a protective effect.

Are annual fluctuations in hip fracture incidence dependent upon the underlying mortality rate?

There is substantial variation in hip fracture incidence rates from one year to the next. To determine whether this is related to varying mortality rates in the underlying population, we carried out an ecological analysis in Rochester and Olmsted County, Minnesota. In a given year, mortality in the general population was not related to hip fracture incidence nor did the fracture incidence rates influence the overall death rate. There was a negative correlation between hip fracture incidence and mortality in the preceding year among women, but not men; the trend was statistically significant among women less than 80 years of age. Both cervical and intertrochanteric hip fractures in women had a similar relationship to mortality in the population the year before. There was no consistent relationship between hip fracture incidence and mortality rates two or three years previously. Although many hip fractures occur in frail individuals near the end of life, patterns of mortality in the underlying population cannot account for the annual variation in hip fracture incidence.