Epidemiology of forearm fractures in women and men in Norway 2008-2019.

The purpose of this paper is to describe rates of forearm fractures in adults in Norway 2008-2019. Incidence rate of distal forearm fractures declined over time in both sexes. Forearm fracture constitute a significant health burden and prevention strategies are needed. PURPOSE: To assess age- and sex-specific incidence rates, and time trends for forearm fractures in Norway, and compare these with incidence rates in other Nordic countries. METHODS: Data on all patients aged 20-107 years with forearm fractures treated in Norwegian hospitals from 2008 to 2019 was retrieved from the Norwegian Patient Registry. Fractures were identified based on International Classification of Disease 10th revision code S52. Age- and sex-specific incidence rates and changes in incidence rates were calculated. RESULTS: We identified 181,784 forearm fractures in 45,628,418 person-years. Mean annual forearm fracture incidence rates per 100,000 person-years were 398 (95% CI 390-407) for all, 565 (95% CI 550-580) for women, and 231 (95% CI 228-234) for men above 20 years. Mean annual number of forearm fractures was 15,148 (95% CI 14,575-15,722). From 2008 to 2019, age-adjusted total incidence rates of forearm fractures S52 diagnoses declined by 3.5% (incidence rate ratio (IRR) of 0.997 (95% CI 0.994-0.999)) in men. The corresponding decline in women was not significant (IRR: 0.999 (95% CI 0.997-1.002)). In the same period, the age-adjusted incidence rates of distal forearm fractures declined by 7.0% in men (IRR = 0.930; 95% CI 0.886-0.965) and 4.7% in women (IRR = 0.953; 95% CI 0.919-0.976). The incidence rates of distal forearm fractures were similar to rates in Sweden and Finland. CONCLUSION: Age-adjusted incidence rates of distal forearm fractures in both sexes declined over time.

Time-varying exposure to anti-osteoporosis drugs and risk of first-time hip fracture: a population wide study within the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS).

We investigated the association between bisphosphonate and denosumab use and risk of hip fracture in Norway. These drugs protect against fractures in clinical trials, but their population-level effect is unknown. Our results showed lowered risk of hip fracture for treated women. Treatment of high-risk individuals could prevent future hip fractures. PURPOSE: To investigate whether bisphosphonates and denosumab reduced the risk of first-time hip fracture in Norwegian women when adjusting for a medication-based comorbidity index. METHODS: Norwegian women aged 50-89 in 2005-2016 were included. The Norwegian prescription database (NorPD) supplied data on exposures to bisphosphonates, denosumab, and other drugs for the calculation of the Rx-Risk Comorbidity Index. Information on all hip fractures treated in hospitals in Norway was available. Flexible parametric survival analysis was used with age as time scale and with time-varying exposure to bisphosphonates and denosumab. Individuals were followed until hip fracture or censoring (death, emigration, age 90 years), or 31 December 2016, whichever occurred first. Rx-Risk score was included as a time-varying covariate. Other covariates were marital status, education, and time-varying use of bisphosphonates or denosumab with other indications than osteoporosis. RESULTS: Of 1,044,661 women 77,755 (7.2%) were ever-exposed to bisphosphonate and 4483 (0.4%) to denosumab. The fully adjusted hazard ratios (HR) were 0.95 (95% confidence interval (CI): 0.91-0.99) for bisphosphonate use and 0.60 (95% CI: 0.47-0.76) for denosumab use. Bisphosphonate treatment gave a significantly reduced risk of hip fracture compared with the population after 3 years and denosumab after 6 months. Fracture risk was lowest in denosumab users who had previously used bisphosphonate: HR 0.42 (95% CI: 0.29-0.61) compared with the unexposed population. CONCLUSIONS: In population-wide real-world data, women exposed to bisphosphonates and denosumab had a lower hip fracture risk than the unexposed population after adjusting for comorbidity. Treatment duration and treatment history impacted fracture risk.

Stumped by the Hump: The Curious Rise and Fall of Norwegian Birthweights, 1991-2007.

BACKGROUND: There was a distinct rise in mean birthweights in Norway starting in 1991 that plateaued in 1996-2002 and then declined to previous levels. We investigated whether these changes corresponded to trends in neonatal mortality or other birthweight-associated pregnancy outcomes. We also explored known predictors of birthweight and examined whether these could explain the birthweight trends. METHODS: We calculated mean birthweight for all live births in Norway in each year from 1982 to 2016, together with annual neonatal mortality and proportion of infants born preterm, or with low Apgar score. We stratified mean birthweight over time by factors including parity, gestational age, and Scandinavian versus non-Scandinavian origin of mother, to test robustness of the pattern. In addition, we used multivariable linear regression to obtain adjusted estimates for mean birthweight per year. RESULTS: A 50-g rise and fall of mean birthweights during a 25-year period was not accompanied by corresponding changes in neonatal mortality, preterm births, or Apgar scores. The distinct hump pattern was restricted to term births and was not apparent among infants of mothers born outside Scandinavia. We saw a similar pattern for Sweden but not Finland. Known predictors of birthweight (such as parity, mode of onset of delivery, and marital status) did not explain the hump. CONCLUSIONS: A distinct temporal hump in mean birthweight among Norwegian term births had no obvious explanations. Furthermore, these fluctuations in birthweight were not associated indirectly with adverse outcomes in measures of infant health.

Milk drinking and risk of hip fracture: the Norwegian Epidemiologic Osteoporosis Studies (NOREPOS).

Milk provides energy and nutrients considered protective for bone. Meta-analyses of cohort studies have found no clear association between milk drinking and risk of hip fracture, and results of recent studies are contradictory. We studied the association between milk drinking and hip fracture in Norway, which has a population characterised by high fracture incidence and a high Ca intake. Baseline data from two population-based cohorts were used: the third wave of the Norwegian Counties Study (1985-1988) and the Five Counties Study (2000-2002). Diet and lifestyle variables were self-reported through questionnaires. Height and weight were measured. Hip fractures were identified by linkage to hospital data with follow-up through 2013. Of the 35 114 participants in the Norwegian Counties Study, 1865 suffered a hip fracture during 613 018 person-years of follow-up. In multivariable Cox regression, hazard ratios (HR) per daily glass of milk were 0·97 (95 % CI 0·92, 1·03) in men and 1·02 (95 % CI 0·96, 1·07) in women. Of 23 259 participants in the Five Counties Study, 1466 suffered a hip fracture during 252 996 person-years of follow-up. HR for hip fractures per daily glass of milk in multivariable Cox regression was 0·99 (95 % CI 0·92, 1·07) in men and 1·02 (95 % CI 0·97, 1·08) in women. In conclusion, there was no overall association between milk intake and risk of hip fracture in Norwegian men and women.

Age and Sex Differences in Body Mass Index as a Predictor of Hip Fracture: A NOREPOS Study.

It is unclear whether very high body mass index (BMI; weight (kg)/height (m)2) lowers risk of hip fracture. Our objectives in this study were 1) to examine the association between BMI and subsequent hip fracture according to sex and age and 2) to explore whether the importance of known risk factors varied across BMI. We followed 61,787 participants (29,511 female and 32,276 male) in the Cohort of Norway (ages 50-79 years at baseline in 1994-2003) with regard to hip fracture. BMI was calculated from measured height and weight. During a median follow-up period of 8.4 years, 1,603 women and 951 men suffered a hip fracture. Hazard ratios for hip fracture and associated 95% confidence intervals were estimated. After adjustment for potential confounders, women with BMI <22 had a hazard ratio of 1.38 (95% confidence interval (CI): 1.18, 1.60) for hip fracture, as compared with women with BMI 22-24.9; and women with BMI ≥30 had a hazard ratio of 0.57 (95% CI: 0.49, 0.66). Corresponding results in men were hazard ratio = 1.66 (95% CI: 1.35, 2.05) and hazard ratio = 0.77 (95% CI: 0.62, 0.96), respectively. Below age 70 years, there was no further decrease in fracture risk at BMIs of 25 or more, while in women aged 70-79 years, the risk continued to decrease with increasing BMI. The associations between risk factors and hip fracture were similar in strength across BMI strata.

Hip fractures in Norway 1999-2008: time trends in total incidence and second hip fracture rates: a NOREPOS study.

Declining incidences of hip fractures are reported from western countries. Norway has among the highest rates in the world. The aim of this study was to investigate trends in total hip fracture rates in Norway between 1999 and 2008 and risk of second hip fractures. All hospitalizations given a hip fracture diagnosis code (International Classification of Diseases (ICD) 9 or ICD 10) (cervical, trochanteric or subtrochanteric) in Norwegian hospitals were retrieved with accompanying surgical procedure codes and additional diagnoses. A total of 93,123 hip fractures were identified between 1999 and 2008 in persons ≥50 years. Annual incidences of hip fractures were calculated and tested for trends. Rates of first and second hip fractures (2006-2008) were compared. The age-standardized total incidence of hip fracture decreased by 13.4 % (95 % confidence interval (CI): 11.0-15.6) in women and 4.8 % (95 % CI: 0.7, 8.7) in men. Age-adjusted rates of second hip fractures did not change in the observation period. In those with a prior hip fracture, the age-standardized risk of a subsequent hip fracture was 2.5-fold (95 % CI: 2.5, 2.6) in women, and 4.6-fold (95 % CI: 4.5, 4.7) in men. Total hip fracture rates declined in both genders during 1999-2008, whereas rates of second hip fractures did not change.

Bone mineral density at the hip in Norwegian women and men--prevalence of osteoporosis depends on chosen references: the Tromsø Study.

This study describes bone mineral density (BMD) and the prevalence of osteoporosis in women and men between 30-89 years in an unselected population. BMD was measured in g/cm(2) at total hip and femoral neck by dual-energy-X-ray absorptiometry in 3,094 women and 2,132 men in the 2001 Tromsø Study. BMD levels were significantly explained by age and declined progressively in both sexes from middle into old age, with highest decline in women. With osteoporosis defined as a T-score of two and a half standard deviation below the young adult mean BMD, the prevalence at the total hip in subjects above 70 years was 6.9% in men and 15.3% in women, respectively, using the Lunar reference material for T-score calculations. The prevalence increased significantly to 7.3% in men and 19.5% in women, when T-scores were calculated on basis of the young adult mean BMD (age group 30-39 years) in the study population. At the femoral neck, prevalence of osteoporosis increased from 13.5 to 18.5% in men, and from 20.4 to 35.2% in women above 70 years, respectively, depending on how T-scores were calculated. The study highlights the challenges with fixed diagnostic levels when measuring normally distributed physiologic parameters. Although BMD only partly explains fracture risk, future studies should evaluate which calculations give optimal fracture prediction.

Urban-Rural Differences in Hip Fracture Mortality: A Nationwide NOREPOS Study.

Higher hip fracture incidence in urban than in rural areas has been demonstrated, but urban-rural differences in posthip fracture mortality have been less investigated, and the results are disparate. Hence, the aims of the present register-based cohort study were to examine possible urban-rural differences in short- and long-term mortality in Norwegian hip fracture patients and their potential associations with sociodemographic variables, and to investigate possible urban-rural differences in excess mortality in hip fracture patients compared with the general population. Data were provided from the NOREPOS hip fracture database, the 2001 Population and Housing Census, and the National Registry. The urbanization degree in each municipality was determined by the proportion of inhabitants living in densely populated areas (rural: <1/3, semirural: 1/3 to 2/3, and urban: >2/3). Age-adjusted mortality rates and standardized mortality ratios were calculated for hip fracture patients living in rural, semirural, and urban municipalities. A flexible parametric model was used to estimate age-adjusted average and time-varying HRs by category of urbanization with the rural category as reference. Among 96,693 hip fracture patients, urban residents had higher mortality than their rural-dwelling counterparts. The HR of mortality in urban compared with rural areas peaked during the first 1 to 2 years postfracture with a maximum HR of 1.20 (95% CI, 1.10 to 1.30) in men and 1.15 (95% CI, 1.08 to 1.21) in women. The differences were significant during approximately 5 years after fracture. Adjusting for sociodemographic variables did not substantially change the results. However, absolute 30-day mortality was not significantly different between urban and rural residents, suggesting that health-care quality immediately postfracture does not vary by urbanization. The novel findings of a higher long-term mortality in urban hip fracture patients might reflect disparities in health status or lifestyle, differences in posthip fracture health care or rehabilitation, or a combination of several factors. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Post-fracture Risk Assessment: Target the Centrally Sited Fractures First! A Substudy of NoFRACT.

The location of osteoporotic fragility fractures adds crucial information to post-fracture risk estimation. Triaging patients according to fracture site for secondary fracture prevention can therefore be of interest to prioritize patients considering the high imminent fracture risk. The objectives of this cross-sectional study were therefore to explore potential differences between central (vertebral, hip, proximal humerus, pelvis) and peripheral (forearm, ankle, other) fractures. This substudy of the Norwegian Capture the Fracture Initiative (NoFRACT) included 495 women and 119 men ≥50 years with fragility fractures. They had bone mineral density (BMD) of the femoral neck, total hip, and lumbar spine assessed using dual-energy X-ray absorptiometry (DXA), trabecular bone score (TBS) calculated, concomitantly vertebral fracture assessment (VFA) with semiquantitative grading of vertebral fractures (SQ1-SQ3), and a questionnaire concerning risk factors for fractures was answered. Patients with central fractures exhibited lower BMD of the femoral neck (765 versus 827 mg/cm2 ), total hip (800 versus 876 mg/cm2 ), and lumbar spine (1024 versus 1062 mg/cm2 ); lower mean TBS (1.24 versus 1.28); and a higher proportion of SQ1-SQ3 fractures (52.0% versus 27.7%), SQ2-SQ3 fractures (36.8% versus 13.4%), and SQ3 fractures (21.5% versus 2.2%) than patients with peripheral fractures (all p < 0.05). All analyses were adjusted for sex, age, and body mass index (BMI); and the analyses of TBS and SQ1-SQ3 fracture prevalence was additionally adjusted for BMD). In conclusion, patients with central fragility fractures revealed lower femoral neck BMD, lower TBS, and higher prevalence of vertebral fractures on VFA than the patients with peripheral fractures. This suggests that patients with central fragility fractures exhibit more severe deterioration of bone structure, translating into a higher risk of subsequent fragility fractures and therefore they should get the highest priority in secondary fracture prevention, although attention to peripheral fractures should still not be diminished. © 2019 American Society for Bone and Mineral Research. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

High prevalence of vertebral fractures and low trabecular bone score in patients with fragility fractures: A cross-sectional sub-study of NoFRACT.

PURPOSE: Norway has among the highest incidence rates of fractures in the world. Vertebral fracture assessment (VFA) and trabecular bone score (TBS) provide information about fracture risk, but their importance have not been studied in Norwegian patients with fragility fractures. The objectives of this study were to examine the clinical characteristics of a cohort of women and men with fragility fractures, their prevalence of vertebral fractures using VFA and prevalence of low TBS, and explore the differences between the sexes and patients with and without vertebral fractures. METHODS: This cross-sectional sub-study of the Norwegian Capture the Fracture Initiative (NoFRACT) included 839 patients with fragility fractures. Of these, 804 patients had bone mineral density (BMD) of the total hip, femoral neck and/or spine assessed using dual energy x-ray absorptiometry, 679 underwent concomitant VFA, 771 had TBS calculated and 696 responded to a questionnaire. RESULTS: Mean age was 65.8 (SD 8.8) years and 80.5% were women. VFA revealed vertebral fractures in 34.8% of the patients and 34.0% had low TBS (≤ 1.23), with no differences between the sexes. In all patients with valid measures of both VFA and TBS, 53.8% had either vertebral fractures, low TBS, or both. In the patients with osteopenia at the femoral neck, 53.6% had either vertebral fractures, low TBS, or both. Femoral neck BMD T-score ≤ -2.5 was found in 13.8% of all patients, whereas the corresponding figure was 27.4% using the skeletal site with lowest T-score. Women exhibited lower BMD at all sites and lower TBS than men (1.27 vs. 1.29), (all p < 0.05). Patients with prevalent vertebral fractures were older (69.4 vs. 64.0 years), exhibited lower BMD at all sites and lower TBS (1.25 vs.1.29) than those without vertebral fractures (all p < 0.05). Before assessment, 8.2% were taking anti-osteoporotic drugs (AOD), and after assessment, the prescription rate increased to 56.2%. CONCLUSIONS: More than half of the patients with fragility fractures had vertebral fractures, low TBS or both. The prescription of AOD increased seven fold from before assessment to after assessment, emphasizing the importance of risk assessment after a fragility fracture.

In vivo and in vitro comparison of densitometers in the NOREPOS study.

The purpose of this study was to assess the agreement of in vivo hip scans on 3 densitometers (1 GE Lunar DPX-IQ and 2 GE Lunar Prodigy scanners) and to evaluate whether the European Spine Phantom (ESP) was able to reproduce the in vivo variability. Sixteen subjects had 3 repeated scans (with repositioning) on each densitometer, and the ESP was measured on each densitometer at least 40 times. Mean differences between hip scans on the Prodigy scanners were small and insignificant, and the in vivo results were not significantly different from the in vitro results. Bland and Altman plots showed no systematic differences between the Prodigy scanners over the range of bone mineral density (BMD). On the other hand, differences between Prodigy and DPX-IQ changed systematically over the range of BMD. The ESP did not fully reproduce the in vivo difference between Prodigy and DPX-IQ. In conclusion, the ESP is a valid substitute when assessing agreement between Prodigy scanners. However, when assessing agreement between different types of scanners, substitution of in vivo with in vitro measurements should be made with caution.

Homocysteine-Lowering Treatment and the Risk of Fracture: Secondary Analysis of a Randomized Controlled Trial and an Updated Meta-Analysis.

High plasma homocysteine is a risk factor for osteoporotic fractures. Several studies have assessed the possible preventive effect of homocysteine-lowering B-vitamin treatment on the risk of fracture with inconclusive results. In the current study, we include new results from the Aspirin Folate Polyp Prevention Study (AFPPS) together with an updated meta-analysis of randomized controlled trials (RCTs). Our objective was to determine whether there is an association between homocysteine-lowering B-vitamin treatment and the risk of fracture. The AFPPS trial was performed between 1994 and 2004 in nine clinical centers in the United States, and 1021 participants were randomized to a daily folic acid dose of 1 mg (n = 516) or placebo (n = 505). The main outcome was fracture of any type. In addition, we analyzed the risk of hip fracture. In the meta-analysis, studies were identified following a search strategy in electronic database and by hand searching. Risk ratio with 95% confidence interval (CI) was chosen for pooled analyses. In the AFPPS, no statistically significant association was found between folic acid treatment and fractures of any type (risk ratio [RR] = 0.95; 95% CI 0.61-1.48) or hip fracture (RR = 0.98; 95% CI 0.25-3.89). In the meta-analysis, six RCTs were included with a total of 36,527 participants. For interventions including folic acid and/or vitamin B12, the pooled RR for treatment was 0.97 (95% CI 0.87-1.09) for fractures of any type (n = 1199) and 1.00 (95% CI 0.81-1.23) for hip fractures (n = 335). In conclusion, no association was found between homocysteine-lowering treatment with B vitamins (folic acid and vitamin B12) and the risk of fracture. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Does the Association of Comorbidity with 1-Year Mortality After Hip Fracture Differ According to Gender? The Norwegian Epidemiologic Osteoporosis Studies (NOREPOS).

BACKGROUND/OBJECTIVES: Excess mortality after hip fracture is higher in men than in women. The objective was to study whether comorbidity differs in men and women with hip fracture and to what degree differences in comorbidity according to gender may explain the higher excess mortality in men. DESIGN: Population-based matched cohort covering the population aged 50 and older in Norway. SETTING: Specialist healthcare (individuals with hip fracture) and general population (controls). PARTICIPANTS: All individuals with hip fracture aged 50 and older from 2005 to 2008 (n = 32,175) and individuals without hip fracture matched 3:1 to those with hip fracture on gender, age, and county of residence (n = 96,410). MEASUREMENTS: Comorbid diagnoses were recorded during the hospital stay. Relative and absolute excess 1-year mortality in individuals with hip fracture according to gender and Charlson Comorbidity Index (CCI) were investigated using Cox regression and linear regression, respectively. RESULTS: Despite lower age (mean 78.7 vs 81.7), men had higher comorbidity than women. Compared with controls, women (hazard ratio (HR) = 6.5, 95% confidence interval (CI) = 6.2-6.9) and men (HR = 7.8, 95% CI = 7.3-8.3) with a CCI of 2 or greater were more likely to die. Women with a CCI of 2 or greater had an estimated 1-year risk of dying of 44%, and controls had an 11% risk; men with a CCI of 2 or greater had an estimated risk of dying of 53%, and controls had a 12% risk. Men were twice as likely as women to die within 1 year (HR = 2.0, 95% CI = 1.9-2.1). When adjusting for comorbidity, the difference was only slightly smaller (HR = 1.8, 95% CI = 1.7-1.8). CONCLUSION: Men had greater comorbidity than women, but this did not explain the difference according to gender in excess mortality after hip fracture. Men who fracture a hip are an especially vulnerable subpopulation, even when there is no apparent comorbidity, and warrant special attention in follow-up and care.

Effect of a Fracture Liaison Service on the Rate of Subsequent Fracture Among Patients With a Fragility Fracture in the Norwegian Capture the Fracture Initiative (NoFRACT): A Trial Protocol.

Importance: Fragility fracture is a major health issue because of the accompanying morbidity, mortality, and financial cost. Despite the high cost to society and personal cost to affected individuals, secondary fracture prevention is suboptimal in Norway, mainly because most patients with osteoporotic fractures do not receive treatment with antiosteoporotic drugs after fracture repair. Objectives: To improve secondary fracture prevention by introducing a standardized intervention program and to investigate the effect of the program on the rate of subsequent fractures. Design, Setting, and Participants: Trial protocol of the Norwegian Capture the Fracture Initiative (NoFRACT), an ongoing, stepped wedge cluster randomized clinical trial in 7 hospitals in Norway. The participating hospitals were cluster randomized to an intervention starting date: May 1, 2015; September 1, 2015; and January 1, 2016. Follow-up is through December 31, 2019. The outcome data were merged from national registries of women and men 50 years and older with a recent fragility fracture treated at 1 of the 7 hospitals. Discussion: The NoFRACT trial is intended to enroll 82 000 patients (intervention period, 26 000 patients; control period, 56 000 patients), of whom 23 578 are currently enrolled by January 2018. Interventions include a standardized program for identification, assessment, and treatment of osteoporosis in patients with a fragility fracture that is led by a trained coordinating nurse. The primary outcome is rate of subsequent fracture (per 10 000 person-years) based on national registry data. Outcomes before (2008-2015; control period) and after (2015-2019; intervention period) the intervention will be compared, and each hospital will act as its own control. Use of outcomes from national registry data means that all patients are included in the analysis regardless of whether they are exposed to the intervention (intention to treat). A sensitivity analysis with a transition window will be performed to mitigate possible within-cluster contamination. Results: Results are planned to be disseminated through publications in peer-reviewed journals and presented at local, national, and international conferences. Conclusions: By introducing a standardized intervention program for assessment and treatment of osteoporosis in patients with fragility fractures, we expect to document reduced rates of subsequent fractures and fracture-related mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02536898.

Educational Inequalities in Post-Hip Fracture Mortality: A NOREPOS Study.

Hip fractures are associated with high excess mortality. Education is an important determinant of health, but little is known about educational inequalities in post-hip fracture mortality. Our objective was to investigate educational inequalities in post-hip fracture mortality and to examine whether comorbidity or family composition could explain any association. We conducted a register-based population study of Norwegians aged 50 years and older from 2002 to 2010. We measured total mortality according to educational attainment in 56,269 hip fracture patients (NORHip) and in the general Norwegian population. Both absolute and relative educational inequalities in mortality in people with and without hip fracture were compared. There was an educational gradient in post-hip fracture mortality in both sexes. Compared with those with primary education only, the age-adjusted relative risk (RR) of mortality in hip fracture patients with tertiary education was 0.82 (95% confidence interval [CI] 0.77-0.87) in men and 0.79 (95% CI 0.75-0.84) in women. Additional adjustments for Charlson comorbidity index, marital status, and number of children did not materially change the estimates. Regardless of educational attainment, the 1-year age-adjusted mortality was three- to fivefold higher in hip fracture patients compared with peers in the general population without fracture. The absolute differences in 1-year mortality according to educational attainment were considerably larger in hip fracture patients than in the population without hip fracture. Absolute educational inequalities in mortality were higher after hip fracture compared with the general population without hip fracture and were not mediated by comorbidity or family composition. Investigation of other possible mediating factors might help to identify new targets for interventions, based on lower educational attainment, to reduce post-hip fracture mortality.

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

UNLABELLED: 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. PURPOSE: The purpose of this study was to examine the possible seasonal variation in hip fracture incidence in Norway by comorbidity, age, and gender. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Mortality following the first hip fracture in Norwegian women and men (1999-2008). A NOREPOS study.

Hip fractures are associated with increased mortality and their incidence in Norway is one of the highest worldwide. The aim of this nationwide study was to examine short- and long-term mortality after hip fractures, burden of disease (attributable fraction and potential years of life lost), and time trends in mortality compared to the total Norwegian population. Information on incident hip fractures between 1999 and 2008 in all persons aged 50 years and older was collected from Norwegian hospitals. Death and emigration dates of the hip fracture patients were obtained through 31 December 2010. Standardized mortality ratios (SMRs) were calculated and Poisson regression analyses were used for the estimation of time trends in SMRs. Among the 81,867 patients with a first hip fracture, the 1-year excess mortality was 4.6-fold higher in men, and 2.8-fold higher in women compared to the general population. Although the highest excess mortality was observed during the first two weeks post fracture, the excess risk persisted for twelve years. Mortality rates post hip fracture were higher in men compared to women in all age groups studied. In both genders aged 50 years and older, approximately 5% of the total mortality in the population was related to hip fractures. The largest proportion of the potential life-years lost was in the relatively young-old, i.e. less than 80 years. In men, the 1-year absolute mortality rates post hip fracture declined significantly between 1999 and 2008, by contrast, the mortality in women increased significantly relatively to the population mortality.

Ten-year risk of second hip fracture. A NOREPOS study.

BACKGROUND: Second hip fracture risk is elevated after the first, however whether risk differs with age, by sex or over time is not well known. OBJECTIVE: To examine the risk of second hip fracture by sex, age and time after first hip fracture. DESIGN: Data on all hip fractures in subjects 50 years and older and treated in Norwegian hospitals during 1999-2008 were retrieved. Surgical procedure codes and additional diagnosis codes were used to define incident fractures. Survival analyses with and without adjustment for competing risk of death were used to estimate the risk of second hip fracture. RESULTS: Among the 81,867 persons who sustained a first hip fracture, 6161 women and 1782 men suffered a second hip fracture during follow-up. The overall age-adjusted hazard ratio (HR) of a second hip fracture did not differ between the sexes (women versus men, HR=1.03; 95% confidence interval (CI): 0.98-1.09). Taking competing risk of death into account, the corresponding age-adjusted HR of a second hip fracture was 1.40 (95% CI: 1.33-1.47) in women compared to men. The greater risk in women was due to a higher mortality in men. Based on competing risk analyses, we estimate that 15% of women and 11% of men will have suffered a second hip fracture within 10 years after the first hip fracture. The ten-year cumulative incidence was above 10% in all age-groups, except in men 90 years and older. CONCLUSION: Fracture preventive strategies have a large potential in both women and men who suffer their first hip fracture due to the high risk of another hip fracture.

Progressively increasing fracture risk with advancing age after initial incident fragility fracture: the Tromsø study.

The risk of subsequent fracture is increased after initial fractures; however, proper understanding of its magnitude is lacking. This population-based study examines the subsequent fracture risk in women and men by age and type of initial incident fracture. All incident nonvertebral fractures between 1994 and 2009 were registered in 27,158 participants in the Tromsø Study, Norway. The analysis included 3108 subjects with an initial incident fracture after the age of 49 years. Subsequent fracture (n = 664) risk was expressed as rate ratios (RR) and absolute proportions irrespective of death. The rates of both initial and subsequent fractures increased with age, the latter with the steepest curve. Compared with initial incident fracture rate of 30.8 per 1000 in women and 12.9 per 1000 in men, the overall age-adjusted RR of subsequent fracture was 1.3 (95% CI, 1.2-1.5) in women, and 2.0 (95% CI, 1.6-2.4) in men. Although the RRs decreased with age, the absolute proportions of those with initial fracture who suffered a subsequent fracture increased with age; from 9% to 30% in women and from 10% to 26% in men, between the age groups 50-59 to 80+ years. The type of subsequent fracture varied by age from mostly minor fractures in the youngest to hip or other major fractures in the oldest age groups, irrespective of type and severity of initial fracture. In women and men, 45% and 38% of the subsequent hip or other major fractures, respectively, were preceded by initial minor fractures. The risk of subsequent fracture is high in all age groups. At older age, severe subsequent fracture types follow both clinically severe and minor initial incident fractures. Any fragility fracture in the elderly reflects the need for specific osteoporosis management to reduce further fracture risk.