Effect of an exercise intervention targeting hip strengthening in patients undergoing revision total hip replacement-A study protocol for a multicenter randomized controlled trial.

BACKGROUND: Limited evidence exists regarding the effectiveness of pain relief and functional improvement in patients undergoing revision total hip replacement (THR). Furthermore, there are no clinical guidelines or consensus on optimal rehabilitation after revision THR. PURPOSE: The primary aim of this study was to compare the effectiveness of an exercise intervention targeting hip strengthening with standard community-based rehabilitation in patients undergoing revision THR. METHODS: This multicenter randomized controlled assessor-blinded trial will be conducted at eight hospitals and multiple municipality rehabilitation centers in Denmark. A total of 84 patients undergoing revision THR are estimated to be allocated to either an exercise intervention targeting hip strengthening (NEMEX-STR) or standard community-based rehabilitation (Usual care). Recruitment was initiated in November 2022 and is expected to be completed by June 2024. The primary outcome is change in functional performance measured by the 30 s chair stand test, from baseline to 4 months after the start of intervention. Secondary outcomes include hip disability and osteoarthritis outcome score; 40 m fast-paced walk test; 9-step timed stair climb test; leg extensor muscle power; global perceived effect; and adverse events. Other outcomes include The International Physical Activity Questionnaires, pain intensity, and European quality of life-5 dimensions. An intention-to-treat approach will be used for analyzing changes in primary and secondary outcome measures. The trial was approved by the Central Denmark Region Committees on Health Research Ethics (Journal No 1-10-72-134-22) and registered on the Central Denmark Regions' internal list of research projects (Journal No 1-16-02-285-22). DISCUSSION: To our knowledge, this study is the first to explore different rehabilitation programs after revision THR through a randomized controlled trial. The results will provide clinically relevant evidence for optimal rehabilitation after revision THR for improving functional performance, physical function, and quality of life, with great importance for patients, relatives, physiotherapists, and decision-makers. CLINICALTRIAL: GOV: NCT05657054.

The impact of comorbidity status on knee function 1 year after total knee arthroplasty: a population-based cohort study.

BACKGROUND AND PURPOSE: Few studies have examined the impact of comorbidity on functional and clinical knee scores after primary total knee arthroplasty (TKA). We compared the effect of having a high Charlson Comorbidity Index (CCI), relative to a low CCI, on changes in the American Knee Society Score (AKSS) functional and clinical scores from baseline to week 52 after TKA in patients with knee osteoarthritis (OA). METHODS: This population-based cohort study included 22,533 patients identified in the Danish Knee Arthroplasty Register from 1997 to 2021. Patients were classified as having low, medium, or high comorbidity based on CCI. The outcome was defined as the mean change (from preoperative to 1-year post-TKA) in functional and clinical knee scores measured by the AKSS (0-100). The association was analyzed using multiple linear regression by calculating mean change scores adjusting for sex, age, weight, cohabiting status, and baseline AKSS. RESULTS: The prevalence of patients with low, medium, and high comorbidity was 75%, 21%, and 4%, respectively. The mean change score in functional AKSS for patients with high comorbidity was -6 points (95% confidence interval [CI] -7 to -5) compared with low comorbidity. The mean change score in clinical AKSS for patients with high comorbidity was -1 point (CI -2 to 0) compared with low comorbidity. CONCLUSION: Patients with knee OA and medium or high comorbidity can expect similar improvements in functional and clinical AKSS after TKA to patients with low comorbidity.

Major comorbid diseases as predictors of infection in the first month after hip fracture surgery: a population-based cohort study in 92,239 patients.

PURPOSE: Comorbidity level is a predictor of infection in the first 30 days after hip fracture surgery. However, the roles of individual comorbid diseases as predictors of infection remain unclear. We investigated individual major comorbid diseases as predictors of infection after hip fracture surgery. METHODS: We obtained Danish population-based medical registry data for patients undergoing hip fracture surgery (2004-2018). Information was obtained on 27 comorbidities, included in various comorbidity indices, 5 years before surgery. The primary outcome was any hospital-treated infection within 30 days after surgery. Cumulative incidence of infection was calculated by considering death as competing risk. We used logistic regression to compute mutually adjusted odds ratios with 95% confidence interval for infection. RESULTS: Of 92,239 patients with hip fracture, 71% were women, and the median age was 83 years. The most prevalent comorbidities were hypertension (23%), heart arrhythmia (15%), and cerebrovascular disease (14%). The 30-day incidence of infection was 15% and 12% among the total cohort and among patients with no record of comorbidities, respectively. Infection incidence was highest among patients with renal disease (24%), depression/anxiety (23%), and chronic pulmonary disease (23%), and lowest among patients with metastatic solid tumor (15%). Adjusted odds ratios of infection ranged from 0.94 [0.80-1.10] for metastatic solid tumor to 1.77 [1.63-1.92] for renal disease. CONCLUSION: Most comorbid diseases were predictors of infection after surgery for hip fracture. Awareness of patients' comorbidity profiles might help clinicians initiate preventive measures or inform patients of their expected risk.

Evaluating the comparability of osteoporosis treatments using propensity score and negative control outcome methods in UK and Denmark electronic health record databases.

Evidence on the comparative effectiveness of osteoporosis treatments is heterogeneous. This may be attributed to different populations and clinical practice, but also to differing methodologies ensuring comparability of treatment groups before treatment effect estimation and the amount of residual confounding by indication. This study assessed the comparability of denosumab vs oral bisphosphonate (OBP) groups using propensity score (PS) methods and negative control outcome (NCO) analysis. A total of 280 288 women aged ≥50 years initiating denosumab or OBP in 2011-2018 were included from the UK Clinical Practice Research Datalink (CPRD) and the Danish National Registries (DNR). Balance of observed covariates was assessed using absolute standardised mean difference (ASMD) before and after PS weighting, matching, and stratification, with ASMD >0.1 indicating imbalance. Residual confounding was assessed using NCOs with ≥100 events. Hazard ratio (HR) and 95% confidence interval (CI) between treatment and NCO was estimated using Cox models. Presence of residual confounding was evaluated with two approaches1: >5% of NCOs with 95% CI excluding 1,2 >5% of NCOs with an upper CI <0.75 or lower CI >1.3. The number of imbalanced covariates before adjustment (CPRD 22/87; DNR 18/83) decreased, with 2-11% imbalance remaining after weighting, matching or stratification. Using approach 1, residual confounding was present for all PS methods in both databases (≥8% of NCOs), except for stratification in DNR (3.8%). Using approach 2, residual confounding was present in CPRD with PS matching (5.3%) and stratification (6.4%), but not with weighting (4.3%). Within DNR, no NCOs had HR estimates with upper or lower CI limits beyond the specified bounds indicating residual confounding for any PS method. Achievement of covariate balance and determination of residual bias were dependent upon several factors including the population under study, PS method, prevalence of NCO, and the threshold indicating residual confounding.

Treatment groups in clinical practice may not be comparable as patient characteristics differ according to the need for the prescribed medication, known as confounding. We assessed comparability of two common osteoporosis treatments, denosumab and oral bisphosphonate, in 280 288 postmenopausal women using electronic health records from UK Clinical Practice Research Datalink (CPRD) and Danish National Registries (DNR). We evaluated comparability of recorded patient characteristics with three propensity score (PS) methods, matching, stratification, and weighting. We assessed residual confounding from unrecorded patient characteristics via negative control outcomes (NCO), events known not to be associated with treatment such as delirium. We found that achieving comparability of osteoporosis treatment groups depended on the study population, PS method, and definition of residual confounding. Weighting and stratification performed the best in DNR and CPRD, respectively. Using a stricter threshold based on statistical significance for the NCO suggested the treatment groups were not comparable, except for PS stratification in DNR. Applying clinically significant thresholds of treatment effect size showed comparability using weighting in CPRD and all PS methods in DNR. Studies should consider more than one PS method to test robustness and identify the largest number of NCO to give the greatest flexibility in detecting residual confounding.

Development and validation of a clinical prediction model for 90-day venous thromboembolism risk following total hip and total knee arthroplasty: a multinational study.

BACKGROUND: The risk of venous thromboembolism (VTE) following total hip arthroplasty (THA) and total knee arthroplasty (TKA) is 1.0% to 1.5%, despite uniform thromboprophylaxis. OBJECTIVES: To develop and validate a prediction model for 90-day VTE risk. METHODS: A multinational cohort study was performed. For model development, records were used from the Oxford Royal College of General Practitioners Research and Surveillance Centre linked to Hospital Episode Statistics and Office of National Statistics UK routine data. For external validation, data were used from the Danish Hip and Knee Arthroplasty Registry, the National Patient Registry, and the National Prescription Registry. Binary multivariable logistic regression techniques were used for development. RESULTS: In the UK data set, 64 032 THA/TKA procedures were performed and 1.4% developed VTE. The prediction model consisted of age, body mass index, sex, cystitis within 1 year before surgery, history of phlebitis, history of VTE, presence of varicose veins, presence of asthma, history of transient ischemic attack, history of myocardial infarction, presence of hypertension and THA or TKA. The area under the curve of the model was 0.65 (95% CI, 0.63-0.67). Furthermore, 36 169 procedures were performed in the Danish cohort, of whom 1.0% developed VTE. Here, the area under the curve was 0.64 (95% CI, 0.61-0.67). The calibration slope was 0.92 in the validation study and 1.00 in the development study. CONCLUSION: This clinical prediction model for 90-day VTE risk following THA and TKA performed well in both development and validation data. This model can be used to estimate an individual's risk for VTE following THA/TKA.

Effect of single versus multiple prophylactic antibiotic doses on prosthetic joint infections following primary total hip arthroplasty in patients with osteoarthritis at public and private hospitals in Denmark: protocol for a nationwide cross-over, cluster randomised, non-inferiority trial [The Pro-Hip-Quality Trial].

INTRODUCTION: A feared complication after total hip arthroplasty (THA) is prosthetic joint infection (PJI), associated with high morbidity and mortality. Prophylactic antibiotics can reduce the risk of PJI. However, there is no consensus on the dosages and current recommendations are based on a low evidence level. The objective is to compare the effect of a single versus multiple doses of prophylactic antibiotics administered within 24 hours on PJI. METHODS AND ANALYSIS: The study is designed as a cross-over, cluster randomised, non-inferiority trial. All clinical centres use both antibiotic practices (1 year of each intervention). All Danish orthopaedic surgery departments will be involved: Based on quality databases, 2-year cohorts of approximately 20 000 primary THAs conducted at 39 public and private hospitals, will be included. INCLUSION CRITERIA: age ≥18 years, all indications for THA except patients operated due to acute or sequelae from proximal femoral or pelvic fractures or bone tumour or metastasis. The primary outcome is PJI within 90 days after primary THA. Secondary outcomes include (1) serious adverse events, (2) potential PJI, (3) length of hospitalisation stay, (4) cardiovascular events, (5) hospital-treated infections, (6) community-based antibiotic use, (7) opioid use and (8) use of acetaminophen and non-steroidal anti-inflammatory drugs. All outcome measures will be extracted from national databases. Analyses will be based on the intention-to-treat population. Non-inferiority will be shown if the upper limit of the two-sided 95% CI for the OR is less than 1.32 for the single dose as compared with multiple doses. The results will establish best practice on antibiotic prophylaxis dosages in the future. ETHICS AND DISSEMINATION: This study has been approved by Committees on Health Research Ethics for The Capital Region of Denmark (21069108) and The Danish Medicines Agency (2021091723). All results will be presented in peer-reviewed medical journals and international conferences. TRIAL REGISTRATION NUMBER: NCT05530551.

Association of anticholinergic drug use with postoperative mortality among patients with hip fracture. A nationwide cohort study.

PURPOSE: Anticholinergic (AC) drugs are associated with various determinantal outcomes. Data regarding the effect of AC drugs on mortality among geriatric hip fracture patients are limited and inconsistent. METHODS: Using Danish health registries, we identified 31,443 patients aged ≥65 years undergoing hip fracture surgery. AC burden was assessed 90 days before surgery by the Anticholinergic Cognitive Burden (ACB) score and number of AC drugs. Logistic and Cox regression producing odds ratios (OR) and hazard ratios (HR) for 30- and 365- day mortality, adjusting for age, sex, and comorbidities were computed. RESULTS: AC drugs were redeemed by 42% of patients. The 30-day mortality increased from 7% for patients with ACB score of 0 to 16% for patients with ACB score of ≥5, corresponding to an adjusted OR 2.5 (CI: 2.0-3.1). The equivalent adjusted HR for 365-mortality was 1.9 (CI: 1.6-2.1). Using count of AC drugs as exposure we found a stepwise increase in ORs and HRs with increased number of AC drugs; Compared to non-users, adjusted ORs for 30-days mortality were 1.6 (CI: 1.4-1.7), 1.9 (CI: 1.7-2.1), and 2.3 (CI: 1.9-2.7) for users of 1, 2 and 3+ AC drugs. HRs for 365-day mortality were 1.4 (CI: 1.3-1.5), 1.6 (CI: 1.5-1.7) and 1.8 (CI: 1.7-2.0). CONCLUSION: Use of AC drugs was associated with increased 30-day and 365-day mortality among older adults with hip fracture. Simply counting the number of AC drugs may be a clinically relevant and easy AC risk assessment tool. Continued effort to reduce AC drug-use is relevant.

Epidemiology of male osteoporosis in Denmark (1996-2018).

Osteoporosis in men may be underdiagnosed. One in four men in Denmark will develop osteoporosis after age of 50 years, with fracture as a common presenting symptom. PURPOSE: The aim of this study was to describe epidemiology of male osteoporosis in Denmark. METHODS: In this nationwide registry-based cohort study, we identified men with osteoporosis, 50 years or older, residing in Denmark, during the years 1996-2018. Osteoporosis was defined as one of the following: a hospital diagnosis of osteoporosis; a hospital diagnosis of osteoporosis fracture; or an outpatient dispensing of an anti-osteoporosis medication. We reported annual incidence and prevalence and described the distribution of fractures, comorbidities, socioeconomic status, and initiation of anti-osteoporosis therapy among men with osteoporosis. Selected characteristics were also described among men without osteoporosis of similar age. RESULTS: There were 171,186 men fulfilling the study criteria for osteoporosis. The overall age-standardized incidence rate of osteoporosis was 8.6 per 1000 person-years (95% confidence interval (CI), 8.5-8.6), varying between 7.7 and 9.7, while the prevalence increased from 4.3% (95% CI, 4.2-4.3) to 7.1% (95% CI, 7.0-7.1) during the 22-year period. The remaining-lifetime risk of developing osteoporosis after age of 50 years was close to 30%. The proportion of men initiating anti-osteoporosis treatment within 1 year of diagnosis increased from 6.9% to 29.8%. Men with osteoporosis had more comorbidities and redeemed more medication than did men without osteoporosis of similar age. CONCLUSION: Osteoporosis among men may be undertreated despite increasing treatment initiation.

Fracture Rates in Children with Cerebral Palsy: A Danish, Nationwide Register-Based Study.

Background: In children with cerebral palsy (CP), fracture rates have been reported to be higher than in the general population but age-specific fracture rates have not been directly compared and the effect of comorbid epilepsy needs elucidation. This impairs decision-making regarding bone health interventions. Aim: We aimed to establish the age-specific fracture rates in children with CP with and without epilepsy in Denmark. Materials and Methods: Data from Danish registers were combined to establish cohorts of children with and without CP born in Denmark from 1997 to 2007. Fracture rates were calculated for 1997-2016. Results: We identified 1,451 children with CP and 787,159 without CP. Female/male fracture rates per 1,000 person-years were 23/27 with CP and 23/29 without CP. Male sex, epilepsy and anti-seizure medication, but not the diagnosis of CP or GMFCS-level, were associated with higher fracture rates. Relatively more lower extremity fractures occurred in non-ambulant children with CP. Interpretation/Conclusion: We found no increased fracture rates in children with CP when compared to peers; however, fracture locations suggested bone fragility in non-ambulant children. All children with epilepsy and on anti-seizure medication had increased fracture rates. We suggest bone health optimization in these groups.

Optimized medial unicompartmental knee arthroplasty outcome: learning from 20 years of propensity score matched registry data.

BACKGROUND AND PURPOSE: Unicompartmental knee arthroplasty (UKA) has increased in use. We investigated changes to UKA revision risk over the last 20 years compared with total knee arthroplasty (TKA), examined external and patient factors for correlation to UKA revision risk, and described the survival probability for current UKA and TKA practice. PATIENTS AND METHODS: All knee arthroplasties reported to the Danish Knee Arthroplasty Register from 1997 to 2017 were linked to the National Patient Register and the Civil Registration System for comorbidity, emigration, and mortality information. All primary UKA and TKA patients with primary osteoarthritis were included and propensity score matched 4 TKAs to 1 UKA. Revision and mortality were analyzed using competing risk cox regression with a shared gamma frailty component. RESULTS: The matched cohort included 48,195 primary knee arthroplasties (9,639 UKAs). From 1997-2001 to 2012-2017 the 3-year hazard ratio decreased from 5.5 (95% CI 2.7-11) to 1.5 (CI 1.2-1.8) due to increased UKA survival. Cementless fixation, a high percentage usage of UKA, and increased surgical volume decreased UKA revision risk, and increased in occurrence parallel to the decreasing revision risks. Current UKA practice using cementless fixation at a high usage unit has a 3-year implant survival of 96% (CI 97-95), 1.1% lower than current TKA practice. INTERPRETATION: UKA revision risk has decreased over the last 20 years, nearing that of TKA surgery. High usage rates, surgical volume, and the use of cementless fixation have increased during the study and were associated with decreased UKA revision risks.

Association of perioperative thromboprophylaxis on revision rate due to infection and aseptic loosening in primary total hip arthroplasty - new evidence from the Nordic Arthroplasty Registry Association (NARA).

BACKGROUND AND PURPOSE: Results regarding the impact of anticoagulants on revision rate are conflicting. We examined the association between the use of low molecular weight heparin (LMWH) or non-vitamin K oral anticoagulants (NOACs) as thromboprophylaxis after primary total hip arthroplasty (THA) and the revision rate due to infection, aseptic loosening, and all causes. PATIENTS AND METHODS: We conducted a cohort study (n = 53,605) based on prospectively collected data from the national hip arthroplasty registries from Denmark and Norway. The outcome was time to revision due to infection, aseptic loosening, and all causes, studied separately. Kaplan-Meier (KM) survival analysis and a Cox proportional hazard model was used to estimate implant survival and cause-specific hazard ratios (HRs) with 95% confidence intervals (CI) adjusting for age, sex, Charlson Comorbidity Index, fixation type, start, and duration of thromboprophylaxis, and preoperative use of Vitamin K antagonists, NOAC, aspirin, and platelet inhibitors as confounders. RESULTS: We included 40,451 patients in the LMWH group and 13,154 patients in the NOAC group. Regarding revision due to infection, the 1-year and 5-year KM survival was 99% in both the LMWH group and in the NOAC group. During the entire follow-up period, the adjusted HR for revision due to infection was 0.9 (CI 0.7-1.1), 1.6 (CI 1.3-2.1) for aseptic loosening, and 1.2 (CI 1.1-1.4) for all-cause revision for the NOAC compared with the LMWH group. The absolute differences in revision rates between the groups varied from 0.2% to 1%. INTERPRETATION: Compared with LMWH, NOACs were associated with a slightly lower revision rate due to infection, but higher revisions rates due to aseptic loosening and all-cause revision. The absolute differences between groups are small and most likely not clinically relevant. In addition, the observed associations might partly be explained by selection bias and unmeasured confounding, and should be a topic for further research.

Prediction Ability of Charlson, Elixhauser, and Rx-Risk Comorbidity Indices for Mortality in Patients with Hip Fracture. A Danish Population-Based Cohort Study from 2014 - 2018.

Objective: Comorbidity has an important role in risk prediction and risk adjustment modelling in observational studies. However, it is unknown which comorbidity index is most accurate to predict mortality in hip fracture patients. We aimed to evaluate the prediction ability, including discrimination and calibration of Charlson comorbidity index (CCI), Elixhauser comorbidity index (ECI) and Rx-risk index for 30 day- and 1 year mortality in a population-based cohort of hip fracture surgery patients. Methods: Using the Danish Multidisciplinary Hip Fracture Registry in the period 2014-2018, 31,443 patients were included. CCI and ECI were based on discharge diagnoses, while Rx-Risk index was based on pharmacy dispensings. We used logistic regression to assess discrimination of the different indices, individually and in combinations, by calculating c-statistics and the contrast in c-statistic to a base model including only age and gender with 95% confidence intervals (CI). Results: The study cohort were primarily female (69%) and older than 85 years (42%). The 30-day mortality was 10.1% and the 1-year mortality was 26.6%. Age and gender alone had a good discrimination ability for 30-day and 1-year mortality (c-statistic=0.70, CI: 0.69-0.71 and c-statistic=0.68, CI: 0.67 -0.69, respectively). By adding indices individually to the base model, Rx-risk index had the best 30-day and 1-year mortality discrimination ability (c-statistic=0.73, CI: 0.72-0.74 and 0.71 CI: 0.71-0.72, respectively). By adding combination of indices to the base model, a combination of CCI and the Rx-risk index had a 30-day and 1-year mortality discrimination ability of c-statistic=0.74, CI: 0.73-0.75 and c-statistic=0.73, CI: 0.73-0.74, respectively. Calibration of indices was similar. Conclusion: The highest discrimination ability was achieved by combining CCI and Rx-risk index in addition to age and gender. However, age and gender alone had a fair mortality discrimination ability.

Interstitial Lung Disease in Connective Tissue Diseases: Survival Patterns in a Population-Based Cohort.

OBJECTIVES: Interstitial lung disease (ILD) is associated with impaired survival among patients with connective tissue diseases (CTDs), but population-based data on the frequency of ILD and pulmonary hypertension (PH) in different CTD subtypes and the impact on survival are sparse. METHODS: We included patients with a first-time ICD-10 diagnosis of systemic sclerosis (SSc), mixed connective tissue disease (MCTD), myositis, systemic lupus erythematosus (SLE), or Sjögren's disease registered in the Danish National Patient Registry between 2000 and 2015. Among these, we identified patients with ILD and PH. Using Kaplan-Meier analysis, we assessed survival for the five subtypes of CTD ± ILD and compared survival among CTD patients overall ± ILD with survival in the general population ± ILD. RESULTS: We identified 11,731 patients with a diagnosis of CTD; 637 (5.4%) had a diagnosis of ILD. The proportion of patients with ILD was higher in SSc (13.4%) and MCTD (9.1%) than in myositis (6.0%), SLE (4.1%), and Sjögren (2.8%). Fifty-one percent were diagnosed with ILD in their fifties and sixties. PH was more frequent in SSc (7.5%) and MCTD (4.1%). Five-year survival was 73.3% (66.7-80.6) in SSc-ILD, 81.0% (69.0-95.1) in MCTD-ILD, 84.7% (77.3-92.9) in myositis-ILD, 83.5% (76.2-91.5) in SLE-ILD, and 84.7 (78.4-91.6) in Sjögren-associated ILD. Survival in CTD-ILD overall was impaired for all age groups compared with CTD alone. Age-stratified survival was comparable between CTD-ILD and ILD in the general population. The survival gap between ILD and non-ILD increased with age. CONCLUSION: Survival was comparable between different CTD-ILD subtypes and comparable to survival in non-CTD-ILD.

Risk factors for new chronic opioid use after hip fracture surgery: a Danish nationwide cohort study from 2005 to 2016 using the Danish multidisciplinary hip fracture registry.

OBJECTIVE: To examine the risk factors for new chronic opioid use in elderly patients who underwent hip fracture surgery. DESIGN: Prospective population-based cohort study. SETTING AND PARTICIPANTS: Using Danish nationwide health registries, we identified all opioid non-user patients aged ≥65 years who had undergone hip fracture surgery from 2005 to 2016 and were alive within the first year following surgery. MAIN OUTCOME MEASURES: New chronic opioid use defined by the dispensing of at least two prescription opioids within two of the last three quarters during the first year following surgery. RESULTS: We identified 37 202 opioid non-user patients who underwent hip fracture surgery. Of these, 5497 (15%) developed new chronic opioid user within 1 year of surgery. Risk factors for new chronic opioid use were Body Mass Index (BMI) of <18.5 (adjusted OR (aOR) 1.22, 95% CI 1.09 to 1.36), BMI of 25.0-29.9 (aOR 1.12, 95% CI 1.04 to 1.21) and BMI of ≥30 (aOR 1.57, 95% CI 1.40 to 1.76) with BMI 18.6-24.9 as reference, a pertrochanteric/subtrochanteric fracture (aOR 1.27, 95% CI 1.20 to 1.34) with femoral neck fracture as reference, preoperative use (vs no-use) of non-steroidal anti-inflammatory drug (aOR 1.68, 95% CI 1.55 to 1.83), selective serotonin reuptake inhibitor (aOR 1.42, 95% CI 1.32 to 1.53), antidepressants (aOR 1.36, 95% CI 1.24 to 1.49), antipsychotics (aOR 1.21, 95% CI 1.07 to 1.35), corticosteroids (aOR 1.54, 95% CI 1.35 to 1.76), statins (aOR 1.09, 95% CI 1.02 to 1.18), antibiotics (aOR 1.32, 95% CI 1.22 to 1.42), antiosteoporosis drugs (aOR 1.33, 95% CI 1.19 to 1.49) and anticoagulatives (aOR 1.24, 95% CI 1.17 to 1.32). Presence of cardiovascular comorbidities, diabetes, gastrointestinal diseases, dementia, chronic obstructive pulmonary disease or renal diseases was further identified as a risk factor. CONCLUSION: In this large nationwide cohort study, we identified several risk factors associated with new chronic opioid use after hip fracture surgery among patients who were alive within the first year following surgery. Although not all factors are modifiable preoperative, this will allow clinicians to appropriately counsel patients preoperatively and tailor postoperative treatment.

Hospital variation in the risk of infection after hip fracture surgery: a population-based cohort study including 29,598 patients from 2012-2017.

Background and purpose - Understanding the key drivers of hospital variation in postoperative infections after hip fracture surgery is important for directing quality improvements. Therefore, we investigated variation in the risk of any infection, and subgroups of infections including pneumonia and sepsis after hip fracture surgery.Methods - In this nationwide population-based cohort study, all Danish patients aged ≥ 65 undergoing surgery for an incident hip fracture from 2012 to 2017 were included. Risk of postoperative infections, based on data from hospital registration (hospital-treated infections) and antibiotic dispensing (community-treated infections), were calculated using multilevel Poisson regression analysis. Hospital variation was evaluated by intra-class coefficient (ICC) and median risk ratio (MRR).Results - The risk of hospital-treated infection was 15%. The risk of community-treated infection was 24%. The adjusted risk varied between hospitals from 7.8-25% for hospital-treated infection and 16-34% for community-treated infection. The ICC indicated that 19% of the adjusted variance was due to hospital level for hospital-treated infection. The ICC for community-treated infections was 13%. The MRR showed a 2-fold increased risk for the average patient acquiring a hospital-treated infection at the highest risk hospital compared with the lowest risk hospital. For community-treated infection, the MRR was 1.4.Interpretation - Our results suggest that 20% of infections could be reduced by applying the top performing hospitals' approach. Nearly a 5th of the variation was at the hospital level. This suggests a more standardized approach to avoid postoperative infection after hip fracture surgery.Hip fracture is a leading cause of hospital admission among the elderly. The 30-day mortality following hip fracture surgery has been approximately 10% during the last few years in Denmark (Pedersen et al. 2017). Higher mortality after hip fracture has been associated with a range of hospital factors (Kristensen et al. 2016, Sheehan et al. 2016) and patient factors in observational studies (Roche et al. 2005). Furthermore, variation in 30-day mortality after hip fracture surgery has been observed between Danish hospitals, but not fully explained (Kristensen et al. 2019).

Mortality and revision risk after femoral neck fracture: comparison of internal fixation for undisplaced fracture with arthroplasty for displaced fracture: a population-based study from Danish National Registries.

Background and purpose - Hemiarthroplasty has lower reoperation frequency and better mobilization compared with internal fixation (IF) in patients with undisplaced femoral neck fractures (FNF), which might translate into lower mortality. In this population-based cohort study we compare the risk of mortality and reoperation in undisplaced FNF treated with IF and displaced FNF treated with arthroplasty in patients older than 70 years old. We assume that, per se, there is no difference in mortality risk between patients with a displaced and an undisplaced FNF.Patients and methods - Hip fracture patients were identified in the Danish Multidisciplinary Hip Fracture Registry during 2005-2015. Data on medication, comorbidities, reoperation, and mortality were retrieved from other Danish medical databases. IF and arthroplasty patients were compared with regards to mortality and reoperation up to 5 years postoperatively. We calculated hazard ratios (HR) with 95% confidence intervals (CI) adjusting for relevant confounders.Results - We included 19,260 FNF treated with arthroplasty and 10,337 FNF with IF. There was an increased risk of mortality for arthroplasty within 30 days, HR 1.3 (95% CI 1.3-1.4), compared with IF but not after 1 and 5 years. Arthroplasty patients had adjusted HRs for reoperation of 0.8 (0.8-0.9) within 1 year, 0.8 (0.7-0.9) within 2 years, and 0.8 (0.8-0.9) within 5 years postoperatively compared with IF.Interpretation - Patients treated for a displaced FNF with arthroplasty had a higher risk of 30-day mortality compared with patients who had an undisplaced FNF treated with IF. It has to be considered that there were baseline differences in the groups but there was no difference in mortality risk up to 5 years post-surgery. Concerning reoperation, patients with a displaced FNF treated with arthroplasty had a lower risk of reoperation compared with IF for undisplaced FNF.

Patient-reported outcomes of 7133 distal femoral, patellar, and proximal tibial fracture patients: A national cross-sectional study with one-, three-, and five-year follow-up.

BACKGROUND: Few studies have described patient-reported outcome measures (PROMs) in knee fracture patients. We reported knee-specific and generic median PROM scores after knee fracture and identified risk factors for poor outcome defined by low median PROM scores. METHODS: In a Danish cross-sectional study of 7133 distal femoral, patellar, and proximal tibial fracture patients during 2011-2017, OKS, FJS-12, EQ5D-5L Index, and EQ5D-5L Visual Analogue Scale (VAS), were collected electronically (response rate 53%; median age 60; 63% female). Poor outcome was defined as score lower than median PROM score. Poor outcome risk factors were estimated as odds ratios from binary logistic regression models. RESULTS: At 0 to one year after knee fracture, median PROM scores were 31 (OKS), 27 (FJS-12), 0.50 (EQ5D-5L Index), and 74 (EQ5D-5L VAS). At >5 years after knee fracture, median OKS score was 40, median FJS-12 score was 54, median EQ5D-5L Index was 0.76, and median EQ5D-5L VAS score was 80. Age > 40 years had higher odds for poor OKS and FJS-12 scores at short- and long-term follow-up after knee fracture. Comorbidity burden, distal femoral fracture, and treatment with external fixation and knee arthroplasty were risk factors for poor outcome at long-term follow-up, for all four PROMs. CONCLUSIONS: Although knee fracture patients have relatively high knee function and quality of life, their ability to forget about the knee joint after knee fracture is compromised. We identified several important risk factors for poor outcome measured by PROMs at different follow-up periods following knee fracture, which will help direct future quality-improvement initiatives.

The Danish Multidisciplinary Hip Fracture Registry 13-Year Results from a Population-Based Cohort of Hip Fracture Patients.

AIM OF THE REGISTRY: The aim of the Danish Multidisciplinary Hip Fracture Registry (DMHFR) is to collect data on processes of treatment, nursing care and rehabilitation as well as outcomes for patients with hip fracture in Denmark, and thereby monitor and improve the quality. STUDY POPULATION: Hip fracture patients at age 65 or older that have undergone surgery with arthroplasty or internal fixation since 2004. MAIN VARIABLES: DMHFR collects quality indicators and descriptive variables. Quality indicators include eight process performance measures within treatment, nursing care and rehabilitation, reflecting recommendations from the national clinical guideline for hip fracture patients, and three outcome measures including survival within 30-days, unplanned acute readmission within 30 days and reoperation within 2 years. Descriptive variables include a number of patient- and surgery-related characteristics. All data are collected prospectively. RESULTS: By the end of 2018, the DMHFR included 86,438 hip fracture patients. Since 2006, all hospital departments in Denmark, treating patients with hip fracture, have reported improvement in quality of care and improvement in survival, and reoperation over time as well as high completeness of variables registration. CONCLUSION: The DMHFR is a well-established nationwide clinical registry, which plays a key role for monitoring and improving hip fracture care in Denmark. The registry can further be linked to a range of other nationwide registries in order to answer a number of relevant clinical research questions.

Use of Opioids and Other Analgesics Before and After Primary Surgery for Adult Spinal Deformity: A 10-Year Nationwide Study.

OBJECTIVE: To report the 1-year pre and postoperative analgesic use in patients undergoing primary surgery for adult spinal deformity (ASD) and assess risk factors for chronic postoperative opioid use. METHODS: Patients > 18 years undergoing primary instrumented surgery for ASD in Denmark between 2006 and 2016 were identified in the Danish National Patient Registry. Information on analgesic use were obtained from the Danish National Health Service Prescription Database. Use of analgesics was calculated one year before and after surgery for each patient, per quarter (-Q4 to -Q1 before and Q1 to Q4 after). Users were defined as patient with one or more prescriptions in the given quarter. RESULTS: We identified 892 patients. Preoperatively, 28% (n = 246) of patients were opioid users in -Q4 and 33% (n = 295) in -Q1. Postoperatively, 85% (n = 756) of patients were opioid users in Q1 and 31% (n = 280) in Q4. Proportions of users of other analgesics (paracetamol, antidepressants, and anticonvulsants) were stable before and after surgery. Use of nonsteroidal anti-inflammatory drug decreased postoperatively by 40% (-Q1 vs. Q4). 26% of patients had chronic preoperative opioid use (one or more prescriptions in each -Q2 and -Q1) and 24% had chronic postoperative use (prescription each of Q1-Q4). Multivariate logistic regression analysis showed age increment per 10 years and preoperative chronic opioid use as risk factors for chronic postoperative opioid use. CONCLUSION: One year after ASD surgery, opioid use was not reduced compared to preoperative usage.

20-year trends of distal femoral, patellar, and proximal tibial fractures: a Danish nationwide cohort study of 60,823 patients.

Background and purpose - Knee fracture treatment burden remains unknown, impeding proper use of hospital resources. We examined 20-year trends in incidence rates (IRs) and patient-, fracture-, and treatment-related characteristics of knee fracture patients.Patients and methods - This nationwide cohort study of prospectively collected data including patients with distal femoral, patellar, and proximal tibial fractures from the Danish National Patient Registry during 1998-2017, assesses IRs of knee fractures (per 105 inhabitants) as well as patient-, fracture-, and treatment-related characteristics of knee fracture patients.Results - During 1998-2017, 60,823 patients (median age 55; 57% female) sustained 74,106 knee fractures. 74% of the study population had a Charlson Comorbidity Index (CCI) of 0 and 18% a CCI of ≥ 2. 51% were proximal tibial fractures, 31% patellar fractures, and 18% distal femoral fractures. At the time of knee fracture, 20% patients had concomitant near-knee fractures (femur/tibia/fibula shaft/hip/ankle), 13% concomitant fractures (pelvic/spine/thorax/upper extremities), 5% osteoporosis, and 4% primary knee osteoarthritis. Over 1/3 knee fractures were surgically treated and of these 86% were open-reduction internal fixations, 9% external fixations, and 5% knee arthroplasties. The most common surgery type was proximal tibia plating (n = 4,868; 60% female). Knee fracture IR increased 12% to 70, females aged > 51 had the highest knee fracture IR, proximal tibial fracture had the highest knee fracture type IR (32) and surgically treated knee fracture IR increased 35% to 23.Interpretation - Knee fracture IRs, especially of surgically treated knee fractures, are increasing and proximal tibial fracture has the highest knee fracture type IR. Females aged > 51 and patients with comorbidity are associated with knee fracture, proximal tibial fracture, proximal tibial fracture surgery, and posttraumatic knee arthroplasty.