Time trends in opioid use for patients undergoing hip fracture surgery in 1997-2018: A Danish population-based cohort study.

BACKGROUND: Although opioids are a mainstay for perioperative pain management in hip fracture patients, no studies have described changes in opioid use over the last two decades. The aim of this study was to describe time trends in opioid use in a population-based cohort of patients undergoing a first-time hip fracture surgery during 1997-2018. METHODS: Opioid-naïve hip fracture patients >55 years old were identified in Danish medical databases (n = 115,962). By 2-year calendar periods, we calculated prevalence rates (PR) of opioid use in the four quarters after surgery (Q1-Q4). Corresponding prevalence rate ratios (PRR) with 1997-1998 as a reference were estimated with 95% confidence intervals. Further, we calculated the median morphine milligram equivalents (MME) for each quarter. RESULTS: For Q1, the PR of opioid use increased from 29% in 1997-1998 to 78% in 2017-2018 corresponding to a PRR of 2.7 (2.6-2.8). For Q4, the PR was 15% in 1997-1998, peaked in 2003-2004 and then decreased, but stayed high at 13% in 2017-2018. The median MME did not increase when comparing 2017-2018 with 1997-1998, irrespective of the quarter. Tramadol was most frequently used in 1997-1998 shifting to oxycodone in 2017-2018. CONCLUSION: The PRs of opioid use in Q1 after surgery increased substantially from 1997 to 2018, but this did not translate into increased opioid use up to 1 year after hip fracture surgery or higher dosage. Our findings underline the importance of sustained focus on opioid tapering, dosage and use of opioids with the lowest potential for addiction and other adverse events. SIGNIFICANCE STATEMENT: Overall, opioid use in Q1 after hip fracture surgery increased 2.7 times from 1997 to 2018, but the doses and opioid use up to 1 year after surgery remained stable. Compared to elderly, younger patients were more likely to use opioid in Q1, while the tendency was opposite in Q2-Q4. The most used opioid type changed from tramadol to oxycodone. Our findings underline the importance of personalized opioid tapering and doses, and use of opioids with the lowest potential for addiction and other adverse events.

Comorbidity and risk of infection among patients with hip fracture: a Danish population-based cohort study.

Impact of comorbidity on infection risk among hip fracture patients is unclear. We found high incidence of infection. Comorbidity was an important risk factor for infection up to 1 year after surgery. Results indicates a need for additional investment in pre- and postoperative programs that assist patients with high comorbidity. PURPOSE: Comorbidity level and incidence of infection have increased among older patients with hip fracture. The impact of comorbidity on infection risk is unclear. We conducted a cohort study examining the absolute and relative risks of infection in relation to comorbidity level among hip fracture patients. METHODS: Utilizing Danish population-based medical registries, we identified 92,600 patients aged ≥ 65 years undergoing hip fracture surgery between 2004 and 2018. Comorbidity was categorized by Charlson comorbidity index scores (CCI): none (CCI = 0), moderate (CCI = 1-2), or severe (CCI ≥ 3). Primary outcome was any hospital-treated infection. Secondary outcomes were hospital-treated pneumonia, urinary tract infection, sepsis, reoperation due to surgical-site infection (SSI), and a composite of any hospital- or community-treated infection. We calculated cumulative incidence and hazard ratios (aHRs) adjusted for age, sex, and surgery year, including 95% confidence intervals (CIs). RESULTS: Prevalence of moderate and severe comorbidity was 40% and 19%, respectively. Incidence of any hospital-treated infection increased with comorbidity level within 0-30 days (none 13% vs. severe 20%) and 0-365 days (none 22% vs. 37% severe). Patients with moderate and severe comorbidity, compared to no comorbidity, had aHRs of 1.3 (CI: 1.3-1.4) and 1.6 (CI: 1.5-1.7) within 0-30 days, and 1.4 (CI: 1.4-1.5) and 1.9 (CI: 1.9-2.0) within 0-365, respectively. Highest incidence was observed for any hospital- or community-treated infection (severe 72%) within 0-365 days. Highest aHR was observed for sepsis within 0-365 days (severe vs. none: 2.7 (CI: 2.4-2.9)). CONCLUSION: Comorbidity is an important risk factor for infection up to 1 year after hip fracture surgery.

Time trends in use of non-steroidal anti-inflammatory drugs and opioids one year after total hip arthroplasty due to osteoarthritis during 1996-2018: a population-based cohort study of 103,209 patients.

OBJECTIVE: To examine time trends in the use of NSAIDs and opioids for patients with osteoarthritis undergoing total hip arthroplasty (THA) during 1996-2018. METHOD: Using Danish population-based medical databases, we identified 103,209 THA patients. Prevalence rates of NSAID and opioid use among preoperative users and non-users were calculated in four quarters (Q1-Q4) after THA by calendar periods (1996-2000, 2001-2006, 2007-2012 and 2013-2018). Prevalence rate ratios (PRR) were adjusted for age and gender. RESULTS: Among preoperative NSAID users and non-users, NSAID use in Q1 increased from 32.6% in 1996-2000 to 48.0% in 2013-2018 (PRR = 1.49, 95% CI: 1.42-1.55) and from 12.9% to 32.0% (PRR = 2.49 (2.32-2.67)), respectively. Among preoperative opioid users and non-users, opioid use in Q1 increased from 42.7% in 1996-2000 to 76.9% in 2013-2018 (PRR = 1.81 (1.73-1.89)) and from 15.2% to 58.2% (PRR = 3.85 (3.65-4.05)), respectively. NSAID use in Q4 decreased from 24.5% in 1996-2000 to 21.4% in 2013-2018 (PRR = 0.88 (0.83-0.93)) and from 6.9% to 5.6% (PRR = 0.81 (0.73-0.91)) in preoperative NSAIDs users and non-users, respectively. Opioid use in Q4 increased from 26.6% in 1996-2000 to 28.6% (PRR = 1.08 (1.02-1.15)) in 2013-2018 and from 4.1% to 5.0% (PRR = 1.25 (1.11-1.40)) in preoperative opioid users and non-users, respectively. CONCLUSION: We observed up to a 4-fold increase in NSAID and opioid use in Q1 during 1996-2018, while usage in Q4 did not change substantially. However, 5-6% of the preoperative non-users of NSAIDs and opioids were users in Q4, which might relate to inaccurate indication for or timing of THA and the post-surgical phasing out of analgesics use.

Risk of infections and mortality in Danish patients with cancer diagnosed with bone metastases: a population-based cohort study.

OBJECTIVES: Risk of infections in patients with solid cancers and bone metastases (BM) and the subsequent impact on prognosis is unclear. We examined the risk of infections among patients with cancer diagnosed with BM and the subsequent impact of infections on mortality. DESIGN: Population-based cohort study. SETTING: Danish medical databases holding information on all hospital contacts in Denmark. PARTICIPANTS: Adult patients with solid cancers and BM between 1 January 1994 and 30 November 2013. OUTCOME MEASURES: In the risk analyses, the outcome was time to hospitalisation for common severe infections, pneumonia, sepsis and urinary tract infections. In the mortality analysis, we used Cox regression to compute HRs of death, modelling infection as time-varying exposure, stratifying for primary cancer type and adjusting for age, sex and comorbidities. RESULTS: Among 23 336 patients with cancer and BM, cumulative incidences of common severe infections were 4.6%, 14.0% and 20.0% during 1 month, 1 year and 10 years follow-up. The highest incidence was observed for pneumonia, followed by urinary tract infections and sepsis. Infection was a strong predictor of 1 month mortality (adjusted HR: 2.1 (95% CI 1.8 to 2.3)) and HRs increased after 1 and 10 years: 2.4 (95% CI 2.3 to 2.6) and 2.4 (95% CI 2.4 to 2.6). Sepsis and pneumonia were the strongest predictors of death. Results were consistent across cancer types. CONCLUSION: Patients with cancer and BM were at high risk of infections, which was associated with a more than twofold increased risk of death for up to 10 years of follow-up. The findings underscore the importance of preventing infections in patients with cancer and BM.

Use of anti-osteoporosis medication dispensing by patients with hip fracture: could we do better?

Although Scandinavian countries have the highest incidence of hip fracture in the world, trends in anti-osteoporosis medication use have not been studied. We found less than one-third of Danish hip fracture patients had dispensing of anti-osteoporosis medication over a 10-year period using routinely collected data from population-based registries. INTRODUCTION: To examine trend in dispensing of anti-osteoporosis medication before and after hip fracture surgery in Denmark over a 10-year period using routinely collected data from population-based registries. METHODS: From the Danish Multidisciplinary Hip Fracture Registry, we included 65,011 patients aged 65 years or older with an incident hip fracture in 2005-2015. We calculated, for each calendar year of hip fracture diagnosis, the prevalence of use of anti-osteoporosis medication (at least one dispensing of bisphosphonates, strontium ranelate, denosumab, selective estrogen receptor modulators, or teriparatide) in the year before and in the year following hip fracture diagnosis. Among those without a dispensing in the year before hip fracture, we computed 1-year cumulative incidence of use following hip fracture. We treated death as a competing risk and stratified the analysis on sex, age, and comorbidity. RESULTS: The prevalence of use before hip fracture varied between 7 and 12%, increasing slightly from 2005 to 2015. The cumulative incidence of use following hip fracture decreased from 16% in 2005 to 13% in 2010, whereupon it increased to 20%. A similar pattern was seen with each stratum of sex, age groups, and comorbidity. The overall prevalence of use after hip fracture was below 22% in all calendar years. CONCLUSIONS: Less than one-third of hip fracture patients had dispensing of anti-osteoporosis medication up to 1 year after hip fracture. We observed only a slight increase in dispensing after hip fracture over the study period, irrespective of patient sex, age, and comorbidity at the time of hip fracture.

Helicobacter pylori infection is not associated with rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is an autoinflammatory disease caused by genetic susceptibility and environmental triggers, which include infectious agents. Helicobacter pylori, a bacterium that frequently colonizes the stomach, is associated with the development of certain autoinflammatory disorders. This study examined a possible association between H. pylori infection and RA. METHOD: This cohort study was performed in the Central Denmark Region. Patients were enrolled from primary healthcare centres after a urea breath test (UBT) for H. pylori and followed for a median of 8 years. Nationwide administrative registries provided information about the patients' diagnoses, country of birth, and gender. Comorbidity was determined using the Charlson Comorbidity Index. We compared the prevalence of RA via odds ratios (ORs) and incidences using Cox regression to calculate the hazard ratios (HRs) by comparing H. pylori-positive and H. pylori-negative individuals and adjusting for confounding variables. RESULTS: A total of 56 000 people diagnosed as H. pylori positive or negative had similar rates of comorbidity. No link was found between H. pylori and RA. There was no difference in RA prevalence until time of UBT [OR = 0.91, 95% confidence interval (CI) 0.70-1.19)] or incidence of new RA cases after UBT (HR = 0.80, 95% CI 0.56-1.13) between H. pylori-positive and -negative subjects. Validation via four other RA definitions provided similar results. CONCLUSION: This study found no association between H. pylori infection and RA. This result does not support the involvement of H. pylori in a gut-joint axis of importance for RA development.

Preoperative antithrombotic therapy and risk of blood transfusion and mortality following hip fracture surgery: a Danish nationwide cohort study.

Hip fracture surgery is associated with high risk of bleeding and mortality. The patients often have cardiovascular comorbidity, which requires antithrombotic treatment. This study found that preoperative use of oral anticoagulants was not associated with transfusion or mortality following hip fracture surgery, whereas increased risk may exist for antiplatelet drugs. INTRODUCTION: Hip fracture surgery is associated with high bleeding risk and mortality; however, data on operative outcomes of hip fracture patients admitted while on antithrombotic therapy is sparse. We examined if preoperative antithrombotic treatment was associated with increased use of blood transfusion and 30-day mortality following hip fracture surgery. METHODS: Using data from the Danish Multidisciplinary Hip Fracture Registry, we identified 74,791 hip fracture surgery patients aged ≥ 65 years during 2005-2016. Exposure was treatment with non-vitamin K antagonist oral anticoagulant (NOAC), vitamin K antagonists (VKA), or antiplatelet drugs at admission for hip fracture. Outcome was blood transfusion within 7 days postsurgery and death within 30 days. RESULTS: A 45.3% of patients received blood transfusion and 10.6% died. Current NOAC use was associated with slightly increased risk of transfusion (adjusted relative risk (aRR) 1.07, 95% confidence interval (CI) 1.01-1.14), but similar mortality risk (adjusted hazard ratio (aHR) 0.88, 95% CI 0.75-1.03) compared with non-users. The pattern remained when restricting to patients with short surgical delay (< 24 h). VKA users did not have increased risk of transfusion or mortality. The risks of transfusion (aRR 1.15 95% CI 1.12-1.18) and 30-day mortality (aHR 1.18 95% CI 1.14-1.23) were increased among antiplatelet users compared with non-users. CONCLUSIONS: In an observational setting, neither preoperative NOAC nor VKA treatments were associated with increased risk of 30-day postoperative mortality among hip fracture patients. NOAC was associated with slightly increased risk of transfusion. Preoperative use of antiplatelet drugs was associated with increased risk of transfusion and mortality.

Excess risk of venous thromboembolism in hip fracture patients and the prognostic impact of comorbidity.

Hip fracture patients were at increased excess risk of venous thromboembolism (VTE) up to 1 year following hip fracture. During the first year, interaction between hip fracture and comorbidity was observed among patients with severe and very severe comorbidity. INTRODUCTION: We compared the risk of VTE in hip fracture patients with that in the general population. We also examined whether and to what extent the association between hip fracture and VTE varied by comorbidity level. METHODS: Nationwide cohort study based on Danish health registries, 1995-2015. We identified hip fracture patients (n = 110,563) and sampled a comparison cohort without hip fracture from the general population (n = 552,774). Comorbidity was assessed using the Charlson comorbidity index. We calculated attributable fraction, as the proportion of the VTE rate, among persons exposed to both hip fracture and comorbidity, attributed to exposure interaction. RESULTS: The cumulative incidences of VTE were 0.73% within 30 days and 0.83% within 31-365 days among hip fracture patients, and 0.05 and 0.43% in the general population. Adjusted hazard ratios (HRs) of VTE among hip fracture patients were 17.29 [95% confidence interval (CI) 14.74-20.28] during the first 30 days and 2.13 (95% CI 1.95-2.32) during 31-365 days following hip fracture. The relative risks of VTE were 1.03 (95% CI 0.96-1.11) and 1.11 (95% CI 1.00-1.23) after 1-5 years and 6-10 years. During the first 30 days and 31-365 days, 14%/28% of VTE rates and 5%/4% of VTE rates were attributable to the interaction between hip fracture and severe/very severe comorbidity, respectively. Mortality risks within 30 days of VTE were 29.4% in hip fracture and 11.0% in general population cohorts. CONCLUSIONS: Hip fracture patients were at increased excess risk of VTE up to 1 year following their fracture. During the first year, interaction between hip fracture and comorbidity was observed among patients with severe and very severe comorbidity.

Venous thromboembolism and risk of cancer in patients with rheumatoid arthritis.

Essentials Can venous thromboembolism (VTE) in rheumatoid arthritis (RA) patients be marker of cancer? RA patients with VTE and comparison cohorts from population-based registries were compared. Increased risk of cancer in RA patients with VTE during the first year of VTE was observed. Risk of cancer in RA patients was increased also during the longer period following VTE. SUMMARY: Background It is unknown whether venous thromboembolism (VTE) in rheumatoid arthritis (RA) patients can be a marker of occult cancer. Objectives To examine risk of cancer subsequent to VTE among RA patients compared with risk of cancer in an RA cohort without VTE and in a general population without RA and without VTE. Patients/Methods All RA patients with a first-time diagnosis of VTE (index date) during 1978-2013 and comparison cohorts were identified from population-based registries in Denmark. Results We identified three cohorts: 2497 RA patients with VTE, 11 672 RA patients without VTE and 12 730 persons from the general population. The cumulative incidence of cancer within the first year of the index date was 3.2% among RA with VTE, 2.2% among RA without VTE, and 2.0% in the general population cohort. Incidence rate ratios (IRRs) were 1.79 (95% confidence interval [CI], 1.37-2.33) for RA patients with VTE vs. RA patients without VTE and 2.12 (95% CI, 1.63-2.76) for RA patients with VTE vs. the general population. The IRR of cancer at > 1 to 36 years from the index date among RA patients with VTE was 1.16 (95% CI, 1.00-1.34) compared with the RA patients without VTE and 1.33 (95% CI, 1.15-1.53) compared with the general population. Conclusions We found an increased risk of cancer in RA patients with VTE during the first year following VTE and also during the longer follow-up period. Thus, VTE may not only be a result of inflammation and immunological dysfunctions associated with RA, but may also be a marker for occult cancer.

Does hydroxyapatite coating of uncemented cups improve long-term survival? An analysis of 28,605 primary total hip arthroplasty procedures from the Nordic Arthroplasty Register Association (NARA).

OBJECTIVE: It is unclear whether hydroxyapatite (HA) coating of uncemented cups used in primary total hip arthroplasty (THA) improves bone ingrowth and reduces the risk of aseptic loosening. We therefore investigated survival of different uncemented cups that were available with or without HA coating. METHOD: We investigated three different cup types used with or without HA coating registered in the Nordic Arthroplasty Register Association (NARA) database that were inserted due to osteoarthritis (n = 28,605). Cumulative survival rates and adjusted hazard ratios (HRs) for the risk of revision were calculated. RESULTS: Unadjusted 13-year survival for cup revision due to aseptic loosening was 97.9% (CI: 96.5-99.4) for uncoated and 97.8% (CI: 96.3-99.4) for HA-coated cups. Adjusted HRs were 0.66 (CI 0.42-1.04) for the presence of HA coating during the first 10 years and 0.87 (CI 0.14-5.38) from year 10-13, compared with uncoated cups. When considering the endpoint cup revision for any reason, unadjusted 13-year survival was similar for uncoated (92.5% [CI: 90.1-94.9]) and HA-coated (94.7% [CI: 93.2-96.3]) cups. The risk of revision of any component due to infection was higher in THA with HA-coated cups than in THA with uncoated cups (adjusted HR 1.4 [CI 1.1-1.9]). CONCLUSIONS: HA-coated cups have a similar risk of aseptic loosening as uncoated cups, thus the use of HA coating seems to not confer any added value in terms of implant stability. The risk of infection seemed higher in THA with use of HA-coated cups, an observation that must be investigated further.

One-year incidence of prosthetic joint infection in total hip arthroplasty: a cohort study with linkage of the Danish Hip Arthroplasty Register and Danish Microbiology Databases.

OBJECTIVE: To examine the trend of Prosthetic Joint Infections (PJI) following primary total hip arthroplasty (THA) and the antimicrobial resistance of the bacteria causing these infections. MATERIALS AND METHODS: We identified a population-based cohort of patients in the Danish Hip Arthroplasty Register (DHR) who had primary THA and received their surgery in Jutland or Funen between 2005 and 2014. We followed the patients until revision, emigration, death, or up to 1-year of follow-up. Data from the DHR were combined with those from microbiology databases, the National Register of Patients, and the Civil Registration System. We estimated the cumulative 1-year incidence of PJI for two 5-year periods; 2005-2009 and 2010-2014. The hazard ratio of PJI as a measure of relative risk after adjusting for multiple risk factors was calculated. RESULTS: Of 48,867 primary THAs identified, 1120 underwent revision within 1 year. Of these, 271 were due to PJI. The incidence of PJI was 0.53% (95% confidence interval (CI): 0.44; 0.63) during 2005-2009 and 0.57% (95% CI: 0.49; 0.67) during 2010-2014. The adjusted relative risk was 1.05 (95% CI: 0.82; 1.34) for the 2010-2014 period vs the 2005-2009 period. The most common micro-organisms identified in the 271 PJI were Staphylococcus aureus (36%) and coagulase-negative staphylococci (CoNS) (33%); others commonly identified included Enterobacteriaceae, enterococci, and streptococci. Antimicrobial resistance to beta-lactams and gentamicin did not change during the study period. CONCLUSION: The risk of PJI within 1-year after primary THA and the antimicrobial resistance of the most prevalent bacteria remained unchanged during the 2005-2014 study period.

Socioeconomic inequality in clinical outcome among hip fracture patients: a nationwide cohort study.

The evidence is limited regarding the association between socioeconomic status and the clinical outcome among patients with hip fracture. In this nationwide, population-based cohort study, higher education and higher family income were associated with a substantially lower 30-day mortality and risk of unplanned readmission after hip fracture. INTRODUCTION: We examined the association between socioeconomic status and 30-day mortality, acute readmission, quality of in-hospital care, time to surgery and length of hospital stay among patients with hip fracture. METHODS: This is a nationwide, population-based cohort study using prospectively collected data from the Danish Multidisciplinary Hip Fracture Registry. We identified 25,354 patients ≥65 years admitted with a hip fracture between 2010 and 2013 at Danish hospitals. Individual-level socioeconomic status included highest obtained education, family mean income, cohabiting status and migrant status. We performed multilevel regression analysis, controlling for potential confounders. RESULTS: Hip fracture patients with higher education had a lower 30-day mortality risk compared to patients with low education (7.3 vs 10.0% adjusted odds ratio (OR) = 0.74 (95% confidence interval (CI) (0.63-0.88)). The highest level of family income was also associated with lower 30-day mortality (11.9 vs 13.0% adjusted OR = 0.77, 95% CI 0.69-0.85). Cohabiting status and migrant status were not associated with 30-day mortality in the adjusted analysis. Furthermore, patients with both high education and high income had a lower risk of acute readmission (14.5 vs 16.9% adjusted OR = 0.94, 95% CI 0.91-0.97). Socioeconomic status was, however, not associated with quality of in-hospital care, time to surgery and length of hospital stay. CONCLUSIONS: Higher education and higher family income were associated with substantially lower 30-day mortality and risk of readmission after hip fracture.

Substantial rise in the lifetime risk of primary total knee replacement surgery for osteoarthritis from 2003 to 2013: an international, population-level analysis.

OBJECTIVE: To estimate and compare the lifetime risk of total knee replacement surgery (TKR) for osteoarthritis (OA) between countries, and over time. METHOD: Data on primary TKR procedures performed for OA in 2003 and 2013 were extracted from national arthroplasty registries in Australia, Denmark, Finland, Norway and Sweden. Life tables and population data were also obtained for each country. Lifetime risk of TKR was calculated for 2003 and 2013 using registry, life table and population data. RESULTS: Marked international variation in lifetime risk of TKR was evident, with females consistently demonstrating the greatest risk. In 2013, Finland had the highest lifetime risk for females (22.8%, 95%CI 22.5-23.1%) and Australia had the highest risk for males (15.4%, 95%CI 15.1-15.6%). Norway had the lowest lifetime risk for females (9.7%, 95%CI 9.5-9.9%) and males (5.8%, 95%CI 5.6-5.9%) in 2013. All countries showed a significant rise in lifetime risk of TKR for both sexes over the 10-year study period, with the largest increases observed in Australia (females: from 13.6% to 21.1%; males: from 9.8% to 15.4%). CONCLUSIONS: Using population-based data, this study identified significant increases in the lifetime risk of TKR in all five countries from 2003 to 2013. Lifetime risk of TKR was as high as 1 in 5 women in Finland, and 1 in 7 males in Australia. These risk estimates quantify the healthcare resource burden of knee OA at the population level, providing an important resource for public health policy development and healthcare planning.

Impact of body mass index on risk of acute kidney injury and mortality in elderly patients undergoing hip fracture surgery.

The literature is limited regarding risk factors for acute kidney injury (AKI) and mortality in hip fracture patients, although AKI is common in these patients. While obese patients were at increased risk of AKI, underweight patients with and without AKI had elevated mortality for up to 1 year after hip fracture surgery, compared with normal-weight patients. INTRODUCTION: This study aimed to examine risk of postoperative AKI and subsequent mortality, by body mass index (BMI) level, in hip fracture surgery patients aged 65 and over. METHODS: A regional cohort study using medical databases was used. We included all patients who underwent surgery to repair a hip fracture during the years 2005-2011 (n = 13,529) at hospitals in Northern Denmark. We calculated cumulative risk of AKI by BMI level during 5 days postsurgery and subsequent short-term (6-30 days postsurgery) and long-term (31-365 days post-surgery) mortality. We calculated crude and adjusted hazard ratios (aHRs) for AKI and death with 95% confidence intervals (CIs), comparing underweight, overweight, and obese patients with normal-weight patients. RESULTS: Risks of AKI within five postoperative days were 11.9, 10.1, 12.5, and 17.9% for normal-weight, underweight, overweight, and obese patients, respectively. Among those who developed AKI, short-term mortality was 14.1% for normal-weight patients compared to 23.1% for underweight (aHR 1.7 (95% CI 1.2-2.4)), 10.7% for overweight (aHR 0.9 (95% CI 0.6-1.1)), and 15.2% for obese (aHR 0.9 (95% CI 0.6-1.4)) patients. Long-term mortality was 24.5% for normal-weight, 43.8% for underweight (aHR 1.6 (95% CI 1.0-2.6)), 20.5% for overweight (aHR 0.8 (95% CI 0.6-1.2)), and 21.4% for obese (aHR 1.1 (95% CI 0.7-1.8) AKI patients. Similar associations between BMI and mortality were observed among patients without postoperative AKI, although the absolute mortality risk estimates by BMI were considerably lower in patients without than in those with AKI. CONCLUSIONS: Obese patients were at increased risk of AKI compared with normal-weight patients. Among patients with and without postoperative AKI, overweight and obesity were not associated with mortality. Compared to normal-weight patients, underweight patients had elevated mortality for up to 1 year after hip fracture surgery irrespective of the presence of AKI. The absolute mortality risks were higher in all BMI groups with the presence of AKI.

Risk of acute renal failure and mortality after surgery for a fracture of the hip: a population-based cohort study.

AIMS: We examined risk of developing acute renal failure and the associated mortality among patients aged > 65 years undergoing surgery for a fracture of the hip. PATIENTS AND METHODS: We used medical databases to identify patients who underwent surgical treatment for a fracture of the hip in Northern Denmark between 2005 and 2011. Acute renal failure was classified as stage 1, 2 and 3 according to the Kidney Disease Improving Global Outcome criteria. We computed the risk of developing acute renal failure within five days after surgery with death as a competing risk, and the short-term (six to 30 days post-operatively) and long-term mortality (31 days to 365 days post-operatively). We calculated adjusted hazard ratios (HRs) for death with 95% confidence intervals (CIs). RESULTS: Among 13 529 patients who sustained a fracture of the hip, 1717 (12.7%) developed acute renal failure post-operatively, including 1218 (9.0%) with stage 1, 364 (2.7%) with stage 2, and 135 (1.0%) with stage 3 renal failure. The short-term mortality was 15.9% and 5.6% for patients with and without acute renal failure, respectively (HR 2.8, 95% CI 2.4 to 3.2). The long-term mortality was 25.0% and 18.3% for those with and without acute renal failure, respectively (HR 1.3, 95% CI 1.2 to 1.5). The mortality was higher in patients with an increased severity of renal failure. CONCLUSION: Acute renal failure is a common complication of surgery in elderly patients who sustain a fracture of the hip, and is associated with increased mortality up to one year after surgery despite adjustment for coexisting comorbidity and medication before surgery. Cite this article: Bone Joint J 2016;98-B:1112-18.

Body mass index, risk of allogeneic red blood cell transfusion, and mortality in elderly patients undergoing hip fracture surgery.

UNLABELLED: Despite improvements in preoperative and postoperative treatment, hip fracture surgery may lead to blood transfusion. Little is known about the impact of body mass index on transfusion risk and subsequent mortality. Opposite overweight and obese patients, underweight patients had increased risk of transfusion and death within 1 year of surgery. INTRODUCTION: Despite improvements in preoperative and postoperative treatment of hip fracture patients, hip fracture surgery may lead to blood loss. We examined the risk of red blood cell transfusion (as an indirect measure of blood loss) and subsequent mortality by body mass index level in patients aged 65 and over undergoing hip fracture surgery. METHODS: This is a population-based cohort study using medical databases. We included all patients who underwent surgery for hip fracture during 2005-2013. We calculated the cumulative risk of red blood cell transfusion within 7 days of surgery treating death as a competing risk and, among transfused patients, short- (8-30 days postsurgery) and long-term mortality (31-365 days postsurgery). RESULTS: Among 56,420 patients, 47.7 % received at least one red blood cell transfusion within 7 days of surgery. In patients with normal weight, the risk was 48.8 % compared with 57.0 % in underweight patients (adjusted RR = 1.11; CI 1.08-1.15), 42.1 % in overweight patients (adjusted RR = 0.89; CI 0.86-0.91), and 42.2 % in obese patients (adjusted RR = 0.87; CI 0.84-0.91). Among transfused patients, adjusted HRs for short-term mortality were 1.52 (CI 1.34-1.71), 0.70 (CI 0.61-0.80), and 0.58 (CI 0.43-0.77) for underweight, overweight, and obese patients, respectively, compared with normal-weight patients. The corresponding adjusted HRs for long-term mortality were 1.45 (CI 1.33-1.57), 0.80 (CI 0.74-0.86), and 0.58 (CI 0.50-0.69). Similar association between BMI and mortality was observed also among non-transfused patients. CONCLUSIONS: Underweight patients had a higher risk of red blood cell transfusion and death in the first year of surgery than normal-weight patients, even when controlling for age and comorbidity. Opposite findings were seen for overweight and obese patients.

Validation of the diagnosis 'prosthetic joint infection' in the Danish Hip Arthroplasty Register.

AIMS: The purpose of this study was to validate the diagnosis of periprosthetic joint infection (PJI) in the Danish Hip Arthroplasty Register (DHR). PATIENTS AND METHODS: We identified a cohort of patients from the DHR who had undergone primary total hip arthroplasty (THA) since 1 January 2005 and followed them until first-time revision, death, emigration or until 31 December 2012. Revision for PJI, as registered in the DHR, was validated against a benchmark which included information from microbiology databases, prescription registers, clinical biochemistry registers and clinical records. We estimated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PJI in the DHR alone and in the DHR when combined with microbiology databases. RESULTS: In total, 1382 of the 37 826 primary THAs in the DHR were registered as having been revised for any cause once 26 patients with errors in registration had been excluded: 232 of these were for PJI. For this group, the sensitivity was 67%, specificity 95%, PPV 77%, and NPV 92%. Combining the data from the DHR with those from microbiology databases increased the sensitivity to 90% and also improved specificity (100%), PPV (98%) and NPV (98%). CONCLUSION: Only two thirds of revisions for PJI were captured in the DHR and only 77% of the PJI reported to the DHR could be confirmed to be infected. TAKE HOME MESSAGE: combining the data from the DHR with those from microbiology databases substantially improved the validity of the diagnosis of PJI and should enable future register-based studies.

Perceived stress and risk of any osteoporotic fracture.

UNLABELLED: Perceived stress is associated with several adverse health outcomes; however, little is known about the impact of stress on fracture risk. In this population-based cohort study, persons with high perceived stress have an increased 5-year risk of any osteoporotic fracture, in particular hip fracture. INTRODUCTION: We conducted a population-based cohort study in Denmark to examine the association between perceived stress and risk of subsequent osteoporotic fracture. METHODS: A 2006 population-based health survey in the Central Danish Region (with 1.25 million inhabitants) was used to identify 7943 persons who were 55 years or older on the survey date and completed the Perceived Stress Scale. Individuals were categorized into two groups: high level of stress and low level of stress (including no stress). We obtained information on all osteoporotic fractures through linkage to the Danish National Registry of Patients. We used Cox regression to compute hazard ratios (HRs) with 95 % confidence interval (CI) adjusted for a number of lifestyle factors, socioeconomic data, perceived general health, and prescription history, comparing high- and low-stress persons. RESULTS: A total of 1799 persons (22.6 %) reported high level of perceived stress, whereas 6144 (77.4 %) reported low level or no stress. The 5-year risk of any osteoporotic fracture was 7.4 and 5.4 % in persons with high and low perceived stress, respectively, corresponding to adjusted HR of 1.37 (CI 1.00-1.89). The adjusted HR for hip fracture within 5 years associated with high perceived stress was 1.68 (CI 1.04-2.72). The associations weakened with increasing follow-up time. CONCLUSIONS: Persons with high perceived stress have an increased risk of any osteoporotic fracture, in particular risk of hip fracture within 5 years of stress assessment even after adjusting for differences in lifestyle, comorbidities, osteoporosis presence, medication use, and socioeconomic status at the time of stress level evaluation. The association attenuated after longer follow-up time.

Association between hospital procedure volume and risk of revision after total hip arthroplasty: a population-based study within the Nordic Arthroplasty Register Association database.

OBJECTIVE: Outcome after total hip arthroplasty (THA) depends on several factors related to the patient, the surgeon and the implant. It has been suggested that the annual number of procedures per hospital affects the prognosis. We aimed to examine if hospital procedure volume was associated with the risk of revision after primary THA in the Nordic countries from 1995 to 2011. DESIGN: The Nordic Arthroplasty Register Association database provided information about primary THA, revision and annual hospital volume. Hospitals were divided into five volume groups (1-50, 51-100, 101-200, 201-300, >300). The outcome of interest was risk of revision 1, 2, 5, 10 and 15 years after primary THA. Multivariable regression was used to assess the relative risk (RR) of revision. RESULTS: 417,687 THAs were included. For the 263,176 cemented THAs no differences were seen 1 year after primary procedure. At 2, 5, 10 and 15 years the four largest hospital volume groups had a reduced risk of revision compared to group 1-50. After 10 years RR was for volume group 51-100 0.79 (CI 0.65-0.95), group 101-200 0.76 (CI 0.61-0.95), group 201-300 0.74 (CI 0.57-0.96) and group >300 0.57 (CI 0.46-0.71). For the uncemented THAs an association between hospital volume and risk of revision were only present for hospitals producing 201-300 THAs per year, beginning at years 2 through 5 and in all subsequent time intervals to 15 years. CONCLUSION: Hospital procedure volume was associated with a long term risk of revision after primary cemented THA. Hospitals operating 50 procedures or less per year had an increased risk of revision after 2, 5, 10 and 15 years follow up.