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Background and purpose — To better detect small changes in postoperative outcome following total hip replacement (THR), the Swedish Hip Arthroplasty Register (SHAR) has decided to change from the EQ-5D-3L (3L) to the EQ-5D-5L (5L). To enable comparison of results obtained with use of the 2 versions of EQ-5D, transferal of results between the questionnaires used is necessary. We assessed the measurement properties of the EQ-5D-5L compared with the EQ-5D-3L, preoperatively and 1-year postoperatively in a Swedish THR population. Patients and methods — Patients eligible for elective THR during 2015 in Western Sweden were invited to the study. With a 2-week separation, the 3L and 5L questionnaires were administered to patients before and 1 year after surgery. Comparing the 2 versions of the EQ-5D, we investigated redistribution of responses, ceiling and floor effects, EQ VAS correlations (Spearman's rank correlation coefficient, rs), and EQ VAS scores for different severity levels by dimension (univariable ordinary least square regression). Results — The additional severity levels of the 5L version were frequently used on both measurement occasions (preoperative mobility 5%, self-care 17%, usual activities 20%, pain 5% and anxiety 3%, postoperative mobility 6%, self-care 5%, usual activities 8%, pain 9%, and anxiety 5%). Ceiling effects of the 3L version diminished overall by 7% using the 5L version. The correlations between the 2 EQ VAS scores obtained with the 3L and 5L instruments were strong both pre- (rs = 0.71) and postoperatively (rs = 0.87). Estimated EQ VAS scores for different levels of severity were consistent for all dimensions except for the mobility dimension of the preoperative 5L version and the anxiety dimension in the postoperative 5L version. Interpretation — Our findings support that the 5L has a higher resolution than the 3L version regarding description of health-related quality of life in patients undergoing THR in Sweden. The EQ VAS scores for different levels of severity agree well between the EQ-5D versions. This could potentially be used to develop a crosswalk value set for transforming 3L to 5L responses in this patient group. [ABSTRACT FROM AUTHOR]

Background: Bilateral THAs performed in the same patient should not be considered independent observations, neither biologically nor statistically. As a result, when surgical results are reviewed, it is common to analyze only the first of the two hips, assuming that the first, and not the second hip of a staged bilateral THA, better resembles unilateral THAs. This assumption has not been empirically justified.Question/purposes (1) In patients with staged bilateral THA, is the first or second hip more similar to a unilateral THA in terms of age at surgery, presence of any preoperative Charlson comorbidity, and risk of postoperative reoperation? (2) Should the date of a first or second hip surgery of a staged bilateral THA be used as a starting point for patient survival to better resemble patients with unilateral THA?Methods: We identified 68,357 THAs due to osteoarthritis in 63,613 patients from the Swedish Hip Arthroplasty Register (SHAR) in 1999-2015. Of those THAs, 14,780 concerned the first hip of a staged bilateral procedure performed between 1999 and 2004; 28,542 were unilaterals from 2004 to 2008, and 25,035 concerned the second hip of a staged bilateral procedure performed 2008 to 2015. We excluded patients who underwent one-stage bilateral THAs. We used different inclusion periods to distinguish unilateral procedures from the first and second hips from staged bilateral procedures because sufficiently long set-up and follow-up periods were needed before and after each period to identify possible contralateral THAs. This introduced potential period confounding, meaning that possible group differences might not be distinguished from unrelated outcome differences over time. We investigated if such time trends existed. It did not for age and reoperation rates, but it did for comorbidity and patient survival. Our primary study endpoint was whether patients with unilateral THAs were more similar to patients with a first hip of a staged bilateral THA, or to patients with their second hip operated. We used Student's t-test to compare mean age at surgery. The proportion of patients with at least one presurgery Charlson comorbidity were compared by 95% bootstrap confidence intervals, after subtracting the yearly time-trend to avoid period confounding. Postoperative risks of reoperation were compared by log-rank tests of Kaplan-Meier curves and by comparing 5-year reoperation rates by pair-wise 95% CIs. Our secondary study endpoint was to compare patient survival for patients with a unilateral THA, a first hip of a staged bilateral THA, or a second hip of a staged bilateral THA. We evaluated this by relative 5-year survival, comparing patients of each group with the general Swedish population of the same age, sex, and year of birth. This way, possible survival differences would be less likely explained by period confounding.Results: Patients undergoing unilateral THA were older than those undergoing a first hip of a staged bilateral THA (70 ± 10 versus 66 ± 9 years, mean difference of 4; p < .001), but they were not different from patients undergoing the second hip of a staged bilateral THA (70 ± 9 years, mean difference of 0; p = 0.74). The period-adjusted proportion of patients with unilateral THA and presurgery comorbidity (Charlson index > 0) was 20% (95% CI: 19.8-20.7). This was no different from patients with a second hip from a staged bilateral THA (20%; 19.7-20.6), but higher compared to patients with a first hip of a staged bilateral THA (15%; 14.5-15.4). For reoperation rates, the log-rank tests showed no difference between unilateral THAs and the second hips of staged bilateral THAs ((Equation is included in full-text article.)). Such difference was found for unilaterals compared with the first hips of staged bilateral THAs ((Equation is included in full-text article.)). The Kaplan-Meier estimate of reoperation rates at 5 years after surgery were also no different for the unilateral THAs compared with the second hips of staged bilateral THAs (3% [95% CI 2.8 to 3.2] for both groups). It was lower (2% [95% CI 1.8 to 2.3]) for a first hip of a staged bilateral THA. For the secondary outcome, the relative 5-year survival differed for all groups. It was 105% (95% CI 104.9 to 105.9) for patients with unilateral THA, 107% (95% CI 106.3 to 107.4) for patients with a second hip from a staged bilateral THA and 109% (95% CI 108.8 to 109.5) for patients with a first hip of a staged bilateral THA. Patients with only a first hip of a planned staged bilateral THA who did not survive long enough to undergo their second THA were classified as unilaterals. The rank-order of survival curves are therefore by design ("immortal time bias"). We conclude, however, that survival for patients with unilateral THA more closely resembles the survival of patients with a second hip of a staged bilateral THA, compared with the first.Conclusions: Our findings, which are based on observational register data, challenge the common practice in epidemiologic studies of analyzing only the first hip of a staged bilateral THA. We recommend analyzing the second THA in a patient who has undergone staged bilateral THA rather than the first because the second procedure better resembles unilateral THA.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background and purpose — Total hip replacement (THR) aims mainly to improve quality of life via restoration of hip function and provision of pain relief. This study sought to assess whether improvements in quality of life between the preoperative and 1-year postoperative period were associated with patient satisfaction Patients and methods — Data were extracted for 69,083 THR operations with complete data reported to the Swedish Hip Arthroplasty Register (SHAR) between 2008 and 2015. Health-related quality of life and patient satisfaction were captured using the Euro-Qol-5D (EQ-5D) and visual analogue scale (VAS), respectively. Multivariable analysis was performed to assess associations between the changes in pre- and postoperative EQ5D and patient satisfaction. Results — In patients reporting severe or moderate problems with mobility preoperatively, improvement to no problems was associated with numerically higher patient satisfaction (coefficient –18 [95% CI –22 to –14] and –18 [–18 to –17]). Improvement in the self-care dimension from severe or moderate problems to no problems was associated with numerically higher patient satisfaction (–15 [–16 to –14] and –13 [–15 to –11]). Improvement from severe problems with the ability to perform usual activities to no problems was associated with numerically higher patient satisfaction (–18 [–19 to –17]). This association was also found for improvement in pain/discomfort and anxiety/depression (–16 [–17 to –15] and –15 [–16 to –14]). Interpretation — Our results indicate that satisfaction with the operated hip is a valid patient-reported outcome reflecting the changes in different EQ-5D dimensions and should be included in the follow-up of patients after THR surgery. [ABSTRACT FROM AUTHOR]

Background and purpose — The direct lateral approach (DLA) and the posterior approach (PA) are the most common surgical approaches in total hip replacement (THR) in Sweden. We investigated how the relationship between surgical approach and risk of reoperation due to dislocation has evolved over time. Patients and methods — Data were extracted from the Swedish Hip Arthroplasty Register from 1999 to 2014. We selected all THRs due to osteoarthritis with head sizes 28, 32, and 36 mm that were performed with either the DLA or the PA. Resurfacing prostheses were excluded. Kaplan–Meier curves for risk of reoperation due to dislocation and all-cause for the 2 surgical approaches were compared for 2 periods (1999–2006 and 2007–2014) up to 2 years postoperatively. We used Cox regression for sex, age, type of fixation, and head size to determine hazard ratios (HR) with DLA set as reference. Results — 156,979 THRs met the selection criteria. In 1999–2006, the PA was associated with increased risk of reoperation due to dislocation (HR 2.3, 95% CI 1.7–3.0) but there was no difference in the risk of all-cause reoperation (HR 1.1, CI 0.9–1.2). In 2007–2014 there was no statistically significant difference in the risk of reoperation due to dislocation (HR 1.2, CI 0.9–1.6) but the risk of all-cause reoperation was lower (HR 0.8, CI 0.7–0.9) for the PA. Interpretation — This study confirms historic reports on the increased risk of early reoperations due to dislocations using the PA compared with the DLA. However, in contemporary practice, the higher risk of reoperation due to dislocation associated with PA has declined, now being similar to that after DLA. We believe improved surgical technique for the PA may explain the results. Surprisingly, the PA was associated with lower risk of all-cause reoperation in 2007–2014. This finding warrants further investigation. [ABSTRACT FROM AUTHOR]

Background: Although the use of thromboprophylaxis is well established, there is no consensus on the preferred thromboprophylaxis regimen after THA; large, population-based studies offer an opportunity to examine this problem in a robust way that can complement results from randomized trials.Questions/purposes: Using data from a large national registry, we asked: (1) Is there any difference between low-molecular weight heparin (LMWH) and new oral anticoagulants in preventing symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE), after THA? (2) Are there any differences in safety parameters, such as bleeding, reoperations and mortality, between LMWH and new oral anticoagulants?Methods: Between 2008 and 2012, 78,066 THAs were performed in Sweden. This study evaluated 32,663 (42%) of them, selected through the merger of several national registries. These patients underwent unilateral THA due to primary osteoarthritis. They had not experienced any venous thromboembolic events 5 years before the index operation and were not prescribed potent antithrombotic agents, of any type, in the 6 months before the index operation. Additionally, their postoperative thromboprophylaxis was confirmed in a national registry by purchase of prescribed medications. We divided the cohort into two groups: those patients who received new oral anticoagulants (5752, 18%) and those who received LMWH (26,881, 82%) as postoperative thromboprophylaxis. Our primary endpoints were the frequencies of symptomatic DVT and symptomatic PE within 3 months of surgery. Our secondary comparison was a between-group comparison of bleeding (by way of diagnostic coding), reoperation, and mortality within 3 months of surgery. Odds ratios (OR) are presented with 95% confidence intervals (CIs) as pooled results for the two groups after adjustment for duration of thromboprophylaxis (short or extended for at least 28 days), year of the index operation, Elixhauser comorbidity index, sex, age and previous treatment with platelet aggregation inhibitors.Results: The risk of symptomatic DVT was lower in the group that received new oral anticoagulants than the group that received LMWH (0.3% versus 0.6%, OR, 0.47; 95% CI, 0.27-0.76; p = 0.026). The risk of symptomatic PE was lower in the group that received new oral anticoagulants than the group that received LMWH (0.1% versus 0.4%, OR, 0.36; 95% CI, 0.16-0.69; p = 0.005). There was no difference in the risk of bleeding (by way of diagnostic coding) (OR, 1.03; 95% CI, 0.82-1.28; p = 0.688), reoperation (OR, 1.02; 95% CI, 0.71-1.44; p = 0.860) or mortality (OR, 0.83; 95% CI, 0.31-1.88; p = 0.883) between groups.Conclusions: New oral anticoagulants were associated with a lower risk of symptomatic DVT and symptomatic PE in this large, registry study, and we observed no differences in the risk of bleeding, reoperation, or death between the groups. Although we were able to control for a number of potential confounding variables, we cannot ascertain the indications that drove the prescription decisions in this setting, and there were important between-group differences in terms of duration of thromboprophylaxis (new oral anticoagulants generally were used for a longer period of time after surgery). Future studies, preferably large randomized trials with pragmatic inclusion criteria, to analyze symptomatic DVT, symptomatic PE and death are needed to confirm or refute our findings.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background and purpose — The association between long-term patient survival and elective primary total hip replacement (THR) has been described extensively. The long-term survival following reoperation of THR is less well understood. We investigated the relative survival of patients undergoing reoperation following elective THR and explored an association between the indication for the reoperation and relative survival. Patients and methods — In this observational cohort study we selected the patients who received an elective primary THR and subsequent reoperations during 1999–2017 as recorded in the Swedish Hip Arthroplasty Register. The selected cohort was followed until the end of the study period, censoring or death. The indications for 1st- and eventual 2nd-time reoperations were analyzed and the relative survival ratio of the observed survival and the expected survival was determined. Results — There were 9,926 1st-time reoperations and of these 2,558 underwent further reoperations. At 5 years after the latest reoperation, relative survival following 1st-time reoperations was 0.94% (95% CI 0.93–0.96) and 0.90% (CI 0.87–0.92) following 2nd-time reoperations. At 5 years patients with a 1st-time reoperation for aseptic loosening had higher survival than expected; however, reoperations performed for periprosthetic fracture, dislocation, and infection had lower survival. Interpretation — The relative survival following 1st- and 2nd-time reoperations in elective THR patients differs by reason for reoperation. The impact of reoperation on life expectancy is more obvious for infection/dislocation and periprosthetic fracture. [ABSTRACT FROM AUTHOR]

Background and purpose — International comparisons of total hip arthroplasty (THA) practices and outcomes provide an opportunity to enhance the quality of care worldwide. We compared THA patients, implants, techniques, and survivorship in Sweden, Australia, and the United States. Patients and methods — Primary THAs due to osteoarthritis were identified using Swedish (n = 159,695), Australian (n = 279,693), and US registries (n = 69,641) (2003–2015). We compared patients, practices, and implant usage across the countries using descriptive statistics. We evaluated time to all-cause revision using Kaplan–Meier survival curves. We assessed differences in countries' THA survival using chi-square tests of survival probabilities. Results — Sweden had fewer comorbidities than the United States and Australia. Cement fixation was used predominantly in Sweden and cementless in the United States and Australia. The direct anterior approach was used more frequently in the United States and Australia. Smaller head sizes (≤ 32 mm vs. ≥ 36 mm) were used more often in Sweden than the United States and Australia. Metal-on-highly cross-linked polyethylene was used more frequently in the United States and Australia than in Sweden. Sweden's 5- (97.8%) and 10-year THA survival (95.8%) was higher than the United States' (5-year: 97.0%; 10-year: 95.2%) and Australia (5-year: 96.3%; 10-year: 93.5%). Interpretation — Patient characteristics, surgical techniques, and implants differed across the 3 countries, emphasizing the need to adjust for demographics, surgical techniques, and implants and the need for global standardized definitions to compare THA survivorship internationally. [ABSTRACT FROM AUTHOR]

Background: All patients undergoing elective total hip replacement (THR) in Sweden are asked to complete a survey, including the EQ-5D. Thus far, EQ-5D values have been presented using the UK TTO value set based on hypothetical values. Shift to the use of the recently introduced Swedish experience-based value set, derived from a representative Swedish population, is an appealing alternative.Purpose: To investigate how accurate the Swedish experience-based VAS value set predicts observed EQ VAS values and to compare correlations between Swedish and UK value sets including two provisional value sets derived from the THR population.Methods: Pre- and one-year postoperative data from 56,062 THR patients from the Swedish Hip Arthroplasty Register were used. Agreement between the observed and the predicted EQ VAS values was assessed with correlation. Based on pre- and postoperative data, we constructed two provisional VAS value sets.Results: Correlations between observed and calculated values using the Swedish VAS value set were moderate (r = 0.46) in preoperative data and high (r = 0.72) in postoperative data. Correlations between UK and register-based value sets were constantly lower compared to Swedish value sets. Register-based values and Swedish values were highly correlated.Conclusions: The Swedish value sets are more accurate in terms of representation of the Swedish THR patients than the currently used UK TTO value set. We find it feasible to use the experience-based Swedish value sets for further presentation of EQ-5D values in the Swedish THR population. [ABSTRACT FROM AUTHOR]

Background and purpose — The hip-related timeline of patients following a total hip arthroplasty (THA) can vary. Ideally patients will live their life without need for further surgery; however, some will undergo replacement on the contralateral hip and/or reoperations. We analyzed the probability of mortality and further hip-related surgery on the same or contralateral hip. Patients and methods — We performed a multi-state survival analysis on a prospectively followed cohort of 133,654 Swedish patients undergoing an elective THA between 1999 and 2012. The study used longitudinally collected information from the Swedish Hip Arthroplasty Register and administrative databases. The analysis considered the patients’ sex, age, prosthesis type, surgical approach, diagnosis, comorbidities, education, and civil status. Results — During the study period patients were twice as likely to have their contralateral hip replaced than to die. However, with passing time, probabilities converged and for a patient who only had 1 non-revised THA at 10 years, there was an equal chance of receiving a second THA and dying (24%). It was 8 times more likely that the second hip would become operated with a primary THA than that the first hip would be revised. Multivariable regression analysis reinforced the influence of age at operation, sex, diagnosis, comorbidity, and socioeconomic status influencing state transition. Interpretation — Multi-state analysis can provide a comprehensive model of further states and transition probabilities after an elective THA. Information regarding the lifetime risk for bilateral surgery, revision, and death can be of value when discussing the future possible outcomes with patients, in healthcare planning, and for the healthcare economy. [ABSTRACT FROM AUTHOR]

Background and purpose — Several studies have reported on the influence of various factors on patient-reported outcomes (PROs) after total hip arthroplasty (THA), but very few have focused on the experience of the surgeon. We investigated any association between surgeons’ experience and PROs 1 year after primary THA. Patients and methods — Patient characteristics and surgical data at 10 hospitals in western Sweden were linked with PROs (EQ-5D-3L, Satisfaction Visual Analogue Scale (VAS), Pain VAS). These data were retrieved from the Swedish Hip Arthroplasty Register (SHAR). The surgeon’s level of experience was divided into 4 subgroups related to experience: < 8 years, 8-15 years, and >15 years of clinical practice after specialist certificate. If no specialist certificate was obtained the surgery was classified as a trainee surgery. Surgeons with >15 years’ experience as an orthopedic specialist were used as reference group in the analyses. Results — 8,158 primary THAs due to osteoarthritis were identified. We identified the surgeons’ level of experience in 8,116 THAs. Data from SHAR on pre- and postoperative PROs and satisfaction at 1 year were available for 6,713 THAs. We observed a statistically significant difference among the 4 groups of surgeons regarding mean patient age, ASA classification, Charnley classification, diagnosis, and fixation technique. At 1-year follow-up, there were no statistically significant differences in Pain VAS, EQ-5D index, or EQ VAS among the subgroups of orthopedic specialists. Patients operated on by orthopedic trainees reported less satisfaction with the result of the surgery compared with the reference group. Interpretation — These findings indicate that patients can expect similar health improvements, pain reduction, and satisfaction 1 year after a primary THA operation irrespective of years in practice after specialty certification as an orthopedic surgeon. [ABSTRACT FROM AUTHOR]

Purpose: We investigated if patient-reported outcomes (PROMs) one year after total hip replacement (THR) can predict the risk of re-operation using data from the Swedish Hip Arthroplasty Register.Methods: A total of 75,899 patients with THR due to osteoarthritis operated in 2002-2014 were included. We used Kaplan-Meier and Cox regression to investigate the relationship between one-year post-operative PROMs and risk of re-operation (all types of further hip surgery). The predictive power of the model and post-operative PROMs were evaluated by concordance index (C).Results: Kaplan-Meier estimates for not being re-operated at eight years was 95.5% (95%CI; 95.3-95.8). Cox regression analyses showed that all PROMs, except for EQ-VAS, were associated with re-operation. The full model had a concordance index of 0.68. Satisfaction (C = 0.65) and pain (C = 0.65) in isolation had the highest predictive power.Conclusions: Worse PROMs predicted higher risk of re-operation. Therefore, we believe PROMs may be helpful in identifying patients at risk for re-operation and timely address their problems. [ABSTRACT FROM AUTHOR]

Abstract: Rationale, aims and objectives: Clinicians considering improvements in health‐related quality of life (HRQoL) after total hip replacement (THR) must account for multiple pieces of information. Evidence‐based decisions are important to best assess the effect of THR on HRQoL. This work aims at constructing a shared decision‐making tool that helps clinicians assessing the future benefits of THR by offering predictions of 1‐year postoperative HRQoL of THR patients. Methods: We used data from the Swedish Hip Arthroplasty Register. Data from 2008 were used as training set and data from 2009 to 2012 as validation set. We adopted two approaches. First, we assumed a continuous distribution for the EQ‐5D index and modelled the postoperative EQ‐5D index with regression models. Second, we modelled the five dimensions of the EQ‐5D and weighted together the predictions using the UK Time Trade‐Off value set. As predictors, we used preoperative EQ‐5D dimensions and the EQ‐5D index, EQ visual analogue scale, visual analogue scale pain, Charnley classification, age, gender, body mass index, American Society of Anesthesiologists, surgical approach and prosthesis type. Additionally, the tested algorithms were combined in a single predictive tool by stacking. Results: Best predictive power was obtained by the multivariate adaptive regression splines (R2 = 0.158). However, this was not significantly better than the predictive power of linear regressions (R2 = 0.157). The stacked model had a predictive power of 17%. Conclusions: Successful implementation of a shared decision‐making tool that can aid clinicians and patients in understanding expected improvement in HRQoL following THR would require higher predictive power than we achieved. For a shared decision‐making tool to succeed, further variables, such as socioeconomics, need to be considered. [ABSTRACT FROM AUTHOR]

Objective: To compare the lifetime risk of total hip replacement (THR) surgery for osteoarthritis (OA) between countries, and over time.Methods: Data on primary THR 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 THR was calculated for 2003 and 2013 using registry, life table, and population data.Results: In 2003, lifetime risk of THR ranged from 8.7% (Denmark) to 15.9% (Norway) for females, and from 6.3% (Denmark) to 8.6% (Finland) for males. With the exception of females in Norway (where lifetime risk started and remained high), lifetime risk of THR increased significantly for both sexes in all countries from 2003 to 2013. In 2013, lifetime risk of THR was as high as 1 in 7 women in Norway, and 1 in 10 men in Finland. Females consistently demonstrated the highest lifetime risk of THR at both time points. Notably, lifetime risk for females in Norway was approximately double the risk for males in 2003 (females 15.9% [95% confidence interval (95% CI) 15.6-16.1], males 6.9% [95% CI 6.7-7.1]), and 2013 (females 16.0% [95% CI 15.8-16.3], males 8.3% [95% CI 8.1-8.5]).Conclusion: Using representative, population-based data, this study found statistically significant increases in the lifetime risk of THR in 5 countries over a 10-year period, and substantial between-sex differences. These multinational risk estimates can inform resource planning for OA service delivery. [ABSTRACT FROM AUTHOR]

Background: Sweden offers a unique opportunity to researchers to construct comprehensive databases that encompass a wide variety of healthcare related data. Statistics Sweden and the National Board of Health and Welfare collect individual level data for all Swedish residents that ranges from medical diagnoses to socioeconomic information. In addition to the information collected by governmental agencies the medical profession has initiated nationwide Quality Registers that collect data on specific diagnoses and interventions. The Quality Registers analyze activity within healthcare institutions, with the aims of improving clinical care and fostering clinical research. Main body: The Swedish Hip Arthroplasty Register (SHAR) has been collecting data since 1979. Joint replacement in general and hip replacement in particular is considered a success story with low mortality and complication rate. It is credited to the pioneering work of the SHAR that the revision rate following hip replacement surgery in Sweden is amongst the lowest in the world. This has been accomplished by the diligent follow-up of patients with feedback of outcomes to the providers of the healthcare along with post market surveillance of individual implant performance. During its existence SHAR has experienced a constant organic growth. One major development was the introduction of the Patient Reported Outcome Measures program, giving a voice to the patients in healthcare performance evaluation. The next aim for SHAR is to integrate patients' wishes and expectations with the surgeons' expertise in the form of a Shared Decision-Making (SDM) instrument. The first step in building such an instrument is to assemble the necessary data. This involves linking the SHARs database with the two aforementioned governmental agencies. The linkage is done by the 10-digit personal identity number assigned at birth (or immigration) for every Swedish resident. The anonymized data is stored on encrypted serves and can only be accessed after double identification. Conclusion: This data will serve as starting point for several research projects and clinical improvement work. [ABSTRACT FROM AUTHOR]

Data from national registries have favored the use of cemented fixation in total hip replacement (THR) while other reports show no significant differences in implant survival between cemented and uncemented fixation using modern implants. It is important to investigate whether the method of fixation itself may affect patient-reported outcomes. Hence, this study sought to analyse if patient-reported outcomes measures (PROMs) differ depending on the type of fixation.~Introduction~Background~Data was used from the follow-up programme of the Swedish Hip Arthroplasty Register which comprises the EQ-5D, a visual analogue scale (VAS) on hip pain, as well as a VAS addressing satisfaction with the outcome of the hip replacement.3,118 patients with uncemented THR due to primary osteoarthritis performed from 2002 to 2011 with complete 1-year follow-up were included in the study. A control group of patients with cemented THR (n = 3,118) were selected by matching on age, gender, Charnley class, and preoperative health-related quality of life.~Methods~Methods~After adjusting for age, gender, Charnley class, and baseline PROMs, multivariate linear regression analyses showed that uncemented fixation is associated with a larger improvement in EQ-5D index (B = 0.03, 95% CI 0.019, 0.041), EQ VAS (B = 2.58, 95% CI 1.65, 3.51), greater pain relief (B = -2.68, 95% CI -3.54, -1.82) and superior patient satisfaction (B = -2.56, 95% CI -3.52, -1.60) (all p<0.001).~Results~Results~This study demonstrates that uncemented fixation is associated with better patient-reported outcomes. Factors unrelated to implant fixation, such as performance or selection bias, may also contribute to the difference.~Discussions~Conclusions [ABSTRACT FROM AUTHOR]

Aims: The EQ-5D questionnaire of EuroQol is an important tool, not only for researchers, but also for quality registers. Until 2013, Sweden did not have a country-specific value set to convert the EQ-5D health states into a single index. Commonly, the UK time trade-off (UK TTO) value set has been used. The study reported here aimed to establish an easy to use tool for the bidirectional crosswalk of the mean EQ-5D values based on two different value sets: the UK TTO and the Swedish TTO value sets. Methods: Using an artificial data set encompassing all possible EQ-5D outcomes, we calculated the EQ-5D index using both the UK TTO and Swedish TTO value sets. Thereafter we modelled the relationship between the two indices using least-squares regression and major axis regression. A series of simulations was run to assess the feasibility of the obtained crosswalk algorithms. Results: Major axis regression was superior to ordinary least-squares regression. Converting the mean EQ-5D values from the UK TTO scale to the Swedish TTO scale was more accurate than the inverse conversion. Values close to the floor and ceiling of the EQ-5D index were more challenging to crosswalk. Conclusions: We established algorithms based on major axis regression to crosswalk EQ-5D values based on the UK TTO and the Swedish TTO value sets. The presented algorithm may facilitate comparisons of EQ-5D values when only mean values are available. The existence of a crosswalk algorithm will ease the transition from the UK TTO to the Swedish TTO value set. [ABSTRACT FROM AUTHOR]

Background and purpose —In Sweden, less than 5% of patients who undergo total hip arthroplasty (THA) have revision. Younger patients have an increased risk of revision. New prosthetic designs are being introduced in order to improve outcomes further. We investigated whether the introductory phase of new cup designs would increase the revision rate. Patients and methods —All THAs and first-time cup revisions performed from 1993 through 2011 were identified in the Swedish Hip Arthroplasty Register. The 15 types of cups used in more than 500 operations and inserted in more than 50 cases in each hospital (n = 52,903) were selected. All cups were given an order number, based on the order in which the cup had been inserted at each hospital. The influence of order number on the risk of revision was analyzed in a regression model, which was adjusted for potentially confounding demographic and surgical data. Revision within 2 years for all reasons (n = 940) was used as primary endpoint. Changes in the risk of revision based on the order number were analyzed using a spline. Results —The order number of the cup had no influence on the risk of early revision (p ≥ 0.7). Categorizing the order number using cutoff values obtained from the splines did not result in any statistically significant changes in risk of revision (p ≥ 0.2). Interpretation —We did not find any increased risk of early revision during the implementation phase of new cup designs. This finding is unexpected, and partly conflicts with data from other registries. The structured and stepwise introduction of new prosthesis designs, facilitated by the annual feedback from the Swedish Hip Arthroplasty Register, may partly explain this discrepancy. [ABSTRACT FROM AUTHOR]

Background and purpose — In preparing patients for total hip replacement surgery, providing thorough information helps to reduce anxiety, manage postoperative pain, prevent complications, and better engage patients in their rehabilitation. However, patient characteristics may have an influence on the ability to comprehend and assimilate the information given. We investigated differences in patients born in Sweden and those born outside Sweden regarding how they perceived the information given before THR, and if this was associated with different patient-reported outcomes one year after surgery. Patients and methods — From Sahlgrenska University Hospital, we recruited 150 patients born in Sweden and 50 patients born outside Sweden who were to undergo THR. We retrieved routinely collected data from the Swedish Hip Arthroplasty Register including basic demographic variables and patient-reported outcome measures, both preoperatively and at 1-year follow-up. In a separate survey carried out 1–2 weeks after surgery, patients were asked about the information provided in connection with the operation. Results — Patients born outside Sweden more frequently reported that they were poorly informed about possibilities to treat pain and about the operation itself. 1 year after the operation, patients born outside Sweden who, 1–2 weeks after the operation, had reported that they were poorly informed also reported having worse outcomes. Poorer results were found for the questions self-care and anxiety/depression in the EQ-5D questionnaire, pain on a visual analog scale (VAS), EQVAS, and EQ-5D index compared to those patients born in Sweden who had received at least some information of acceptable quality. Interpretation — One quarter of the patients were not satisfied with the information provided before and after THR. These patients more commonly reported perioperative anxiety and they were more often born outside Sweden. Poorly informed patients who had come from countries outside Sweden were more likely to report inferior outcome 1 year after the operation. [ABSTRACT FROM PUBLISHER]

Objective:To identify early diagnostic profiles such as diagnostic codes and consultation patterns of cancer patients in primary care one year prior to cancer diagnosis. Design:Total population-based case–control study. Setting and subjects:4562 cancer patients and 17,979 controls matched by age, sex, and primary care unit. Data were collected from the Swedish Cancer Register and the Regional Healthcare Database. Method:We identified cancer patients in the Västra Götaland Region of Sweden diagnosed in 2011 with prostate, breast, colorectal, lung, gynaecological, and skin cancers including malignant melanoma. We studied the symptoms and diagnoses identified by diagnostic codes during a diagnostic interval of 12 months before the cancer diagnosis. Main outcome measures:Consultation frequency, symptom density by cancer type, prevalence and odds ratios (OR) for the diagnostic codes in the cancer population as a whole. Results:The diagnostic codes with the highest OR were unspecified lump in breast, neoplasm of uncertain behaviour, and abnormal serum enzyme levels. The codes with the highest prevalence were hyperplasia of prostate, other skin changes and abdominal and pelvic pain. The frequency of diagnostic codes and consultations in primary care rose in tandem 50 days before diagnosis for breast and gynaecological cancer, 60 days for malignant melanoma and skin cancer, 80 days for prostate cancer and 100 days for colorectal and lung cancer. Conclusion:Eighty-seven percent of patients with the most common cancers consulted a general practitioner (GP) a year before their diagnosis. An increase in consultation frequency and presentation of any symptom should raise the GP’s suspicion of cancer.Key pointsKnowledge about the prevalence of early symptoms and other clinical signs in cancer patients in primary care remains insufficient.• Eighty-seven percent of the patients with the seven most common cancers consulted a general practitioner 12 months prior to cancer diagnosis.• Both the frequency of consultation and the number of symptoms and diseases expressed in diagnostic codes rose in tandem 50–100 days before the cancer diagnosis.• Unless it is caused by a previously known disease, an increased consultation rate for any symptom should result in a swift investigation or referral from primary care to confirm or exclude cancer. [ABSTRACT FROM PUBLISHER]

Background: Comorbidities influence surgical outcomes and therefore need to be included in risk adjustment when predicting patient-reported outcomes. However, there is no consensus on how best to use the available data about comorbidities in registry-based predictive models.Questions/purposes: The purposes of this study were (1) to determine whether the International Classification of Diseases, 10(th) Revision (ICD-10)-based comorbidity measures (Elixhauser, Charlson, and Royal College of Surgeons Charlson) offer added value in explaining patients' health-related quality of life (HRQoL), pain, and satisfaction after total hip arthroplasty (THA) when preoperative HRQoL, pain, and Charnley classification were known; and (2) to determine the ideal timeframe for recording the different diagnoses that serves as the basis for comorbidity measure calculations.Methods: There were 22,263 patients who had undergone THA with complete pre- and postoperative patient-reported outcome measures (PROMs) included in the Swedish Hip Arthroplasty Register between 2002 and 2007. The three comorbidity indices were calculated with ICD-10 codes identified in the Swedish National Patient Register from 1, 2, and 5 years before the patient underwent THA. The impact of the comorbidity indices on the PROM scores (EQ-5D index, EQ visual analog scale [VAS], pain VAS, and satisfaction VAS) was modeled with linear regression where the 1-year patient postoperative outcome score was the dependent variable and independent variables included patient preoperative Charnley classification, preoperative HRQoL and pain, and comorbidity indices. The partial R(2) value indicated how much each variable uniquely contributed to the predictive capacity of the model.Results: The ICD-10-based comorbidity measures added little predictive value to the models for each of the outcomes of interest (EQ-5D index, EQ VAS, pain VAS, and satisfaction VAS). Charnley classification and the preoperative scores were the strongest predictors of both measures of postoperative HRQoL, of postoperative pain, and postoperative satisfaction with outcomes from surgery. Of all the predictors considered, only the Charnley classification was associated with all outcomes, irrespective of the timeframe considered. For each of the outcomes considered, there was a gradual increase in the models' predictive power with the length of the timeframe considered for calculating the comorbidity measures.Conclusions: For predicting outcomes 1 year after THA, we found that there was no added value in ICD-10-based comorbidity measures if patient Charnley classification and preoperative HRQoL and pain measures were known.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Radiostereometric analysis (RSA) is an accurate and precise measurement tool of migration and rotation of implants. We investigated if early migration measured with RSA can be used to predict the risk of later aseptic loosening in acetabular revision surgery.~Introduction~Background~A total of 312 patients who underwent acetabular revision surgery were followed by RSA measurements for 2 to 20 years. The endpoint was either re-revision due to aseptic loosening or loosening on last available radiographic examination. Cox regression model was used to evaluate the predictive value of early migration.~Patients and Methods~Methods~A total of 16 acetabular cups were re-revised due to aseptic loosening and 7 unrevised cups were radiographically loose. Every mm of proximal migration 2 years postoperatively increased the risk of aseptic loosening by 37% (hazard ratio (HR) 1.37, 95% confidence interval (CI) 1.18-1.58). Adjusting for differences in base line demographics, bone defects and surgical techniques in a Cox regression model, risk of aseptic loosening with every mm of proximal migration was even higher (HR 1.94, 95% CI 1.34-2.82, p<0.001).~Results~Results~We found a strong relationship between early migration measured by RSA and risk of late aseptic loosening in acetabular revision surgery. Monitoring proximal migration with RSA should be considered as an essential step in quality assessment when new implants and novel techniques are introduced in acetabular revision surgery.~Conclusions~Conclusions [ABSTRACT FROM AUTHOR]

Background and purpose - The incidence of knee osteoarthritis will most likely increase. We analyzed historical trends in the incidence of knee arthroplasty in Sweden between 1975 and 2013, in order to be able to provide projections of future demand. Patients and methods - We obtained information on all knee arthroplasties in Sweden in the period 1975-2013 from the Swedish Knee Arthroplasty Register, and used public domain data from Statistics Sweden on the evolution of and forecasts for the Swedish population. We forecast the incidence, presuming the existence of a maximum incidence. Results - We found that the incidence of knee arthroplasty will continue to increase until a projected upper incidence level of about 469 total knee replacements per 105 Swedish residents aged 40 years and older is reached around the year 2130. In 2020, the estimated incidence of total knee arthroplasties per 105 Swedish residents aged 40 years and older will be 334 (95% prediction interval (PI): 281-374) and in 2030 it will be 382 (PI: 308-441). Using officially forecast population growth data, around 17,500 operations would be expected to be performed in 2020 and around 21,700 would be expected to be performed in 2030. Interpretation - Today's levels of knee arthroplasty are well below the expected maximum incidence, and we expect a continued annual increase in the total number of knee arthroplasties performed. [ABSTRACT FROM AUTHOR]

Background and purpose - The continuously increasing demand for joint replacement surgery in the past decades imposes higher constraints on the budgets of hospitals and healthcare providers. We undertook an analysis of historical trends in total hip replacement performed in Sweden between 1968 and 2012 in order to provide projections of future demand. Data and methods - We obtained data on total hip replacements registered every year and on the evolution of the Swedish population between 1968 and 2012. We assumed the existence of a maximum incidence. So we adopted a regression framework that assumes the existence of an upper limit of total hip replacement incidence. Results - We found that the incidence of total hip replacement will continue to increase until a projected upper incidence level of about 400 total hip replacements per 105 Swedish residents aged 40 years and older will be reached around the year 2107. In 2020, the estimated incidence of total hip replacement will be 341 (95% prediction interval (PI): 302-375) and in 2030 it will be 358 (PI: 317-396). Using official forecasted population growth data, about 18.000 operations would be expected to be performed in 2020 and 20.000 would be expected to be performed in 2030. Interpretation - Growing incidence, population growth, and increasing life expectancy will probably result in increased demand for hip replacement surgery. Our findings could serve as a basis for decision making. [ABSTRACT FROM AUTHOR]

Background: Age, sex, and medical comorbidities may be associated with differences in patient-reported outcome scores after THA. Highest level of education may be a surrogate for socioeconomic status, but the degree to which this is associated with patient-reported outcomes after THA is not known. Questions/purposes: We investigated the national Swedish Hip Arthroplasty Register for the association of education attainment on patient-reported outcomes 1 year after THA; specifically, we evaluated level of education attainment against health-related quality of life (HRQoL), pain reduction, and satisfaction with treatment 1 year after THA. Methods: All THAs for osteoarthritis performed from 2005 through 2007 with complete patient-reported outcome measures (representing 49% of the THAs performed for this diagnosis) were selected from the Swedish Hip Arthroplasty Register. These cases were merged with national databases containing education attainment, marital status, and comorbidities (n = 11,464; mean age of patients, 64 years). The patient-reported outcome measure protocol included the HRQoL measure EuroQol five-dimension scale (EQ-5D), a VAS for pain, the Charnley classification survey, and a VAS addressing THA satisfaction. Linear regression analyses determined the association of preoperative patient factors with patient-reported outcomes. Results: High education attainment was associated with higher HRQoL (EQ-5D index ß = 0.03 ± 0.01; EQ VAS ß = 2.6 ± 0.5) after THA, whereas those with low and medium education were at risk for lower HRQoL. High education was associated with less pain after treatment (ß = −3.3 ± 0.05). Individuals with low or medium education were at risk for less satisfaction with THA (p < 0.001). Conclusions: Our results suggest clinicians should support patients with low and medium education to a greater extent. Identification of patients who will benefit most from THA and educating those at risk for poorer outcomes, like patients with low and medium education, ultimately may improve patient satisfaction, HRQoL, pain, and the cost utility of THA. Level of Evidence: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

The only form of haemophilia treatment that is able to prevent arthropathy and other consequences of bleeding symptoms in patients with severe haemophilia is prophylaxis started at an early age (primary prophylaxis). It is also highly beneficial for the psychological and social wellbeing of patients and their families. Scientific institutions and international organizations such as WHO, the World Federation of Hemophilia (WFH) and the National Haemophilia Foundation (NHF) have recommended that prophylaxis be considered optimum therapy. This paper discusses the barriers to prophylaxis, such as the perceived need, costs and availability, and difficulty of venous access, and describes the authors' experiences with the therapy. [ABSTRACT FROM AUTHOR]

Background: Health care on equal terms is a cornerstone of the Swedish health care system. Total hip arthroplasty (THA) is considered a success story in Sweden with low frequency of reoperations and restored health-related quality of life (HRQoL). Administratively, health care in Sweden is locally self-governed by 21 counties. In this longitudinal nation-wide observational study we assessed the possible geographical variations in 1-year follow-up patient-reported outcomes (PROs): EQ-5D index, EQ VAS, Pain VAS and Satisfaction VAS.Methods: Study population consisted of 36,235 Swedish THA patients, operated during 2008 to 2012 due to hip osteoarthritis. Individual data came from Swedish Hip Arthroplasty Register, Statistics Sweden and National Board of Health and Welfare. We used descriptive statistics together with multivariable regression analysis to analyse the data.Results: We observed county level differences in both preoperative and postoperative PROs. The results showed that the differences observed in preoperative PROs could not fully explain the differences observed in postoperative PROs, even after adjustment for patient demographics (age, sex, BMI, Elixhauser comorbidity index, marital status, educational level and disposable income). This indicates that other factors might influence the outcome after THA.Conclusion: Likely, structural and process differences such as indication for surgery have an influence on PROs after surgery. Standardization of care at hospital levels may decrease geographical variations in postoperative HRQoL. Remaining differences will then possibly be associated to patient demographics. [ABSTRACT FROM AUTHOR]

• We show that relative entropy is a useful index of soil structure at the regional scale. • Clay content and parent material most important for explaining variations in soil structure. • Evidence that soil structure deteriorates below ca. 2–3% soil organic carbon content. • Agricultural intensification in the recent past drove structural changes through compaction. The evolution of soil structure in agricultural soils is driven by natural and anthropogenic factors including inherent soil properties, climate and soil management interventions, all acting at different spatial and temporal scales. Although the causal relationships between soil structure and these individual factors are increasingly understood, their relative importance and complex interactive effects on soil structure have so far not been investigated across a geo-climatic region. Here we present the first attempt to identify the relative importance of factors that drive the evolution of soil structure in agricultural soils as well as their direction of effect with a focus on the temperate-boreal zone. This was done using a random forest (RF) approach including soil, climate, time, and site factors as covariates. Relative entropy, as quantified by the Kullback-Leibler (KL) divergence, was used as a quantitative index of soil structure, which is derived from the particle-size distribution and soil water retention data, and integrates the effects of soil structure on pores from the micrometre-scale to large macropores. Our dataset includes 431 intact topsoil and subsoil samples from 89 agricultural sites across Sweden and Norway, which were sampled between 1953 and 2017. The relative importance of covariates for the evolution of soil structure was identified and their non-linear and non-monotonic effects on the KL divergence were investigated through partial dependence analysis. To reveal any differences between topsoils (0–30 cm; n = 174) and subsoils (30–100 cm; n = 257), the same analysis was repeated separately on these two subsets. The covariates were able to explain on average more than 50% of the variation in KL divergence for all soil samples and when only subsoil samples were included. However, the predictions were poorer for topsoil samples (≈ 35%), underlining the complex dynamics of soil structure in agricultural topsoils. Parent material was the most important predictor for the KL divergence, followed by clay content for all soil samples and sampling year for only subsoil samples. Mean annual air temperature ranked third and annual precipitation ranked fourth for subsoil samples. However, it remains unclear whether the effects of climate factors are direct (e.g., freezing and thawing, wetting and drying, rainfall impact) or indirectly expressed through interactions with soil management. The partial dependence analysis revealed a soil organic carbon threshold of around 3% below which soil structure starts to deteriorate. Besides this, our results suggest that subsoil structure in the agricultural land of Sweden deteriorated steadily during the 1950′s to 1970′s, which we attribute to traffic compaction as a consequence of agricultural intensification. We discuss our findings in the light of data bias, laboratory methods and multicollinearity and conclude that the approach followed here gave valuable insights into the drivers of soil structure evolution in agricultural soils of the temperate-boreal zone. Theses insights will be of use to inform soil management interventions that address soil structure or soil properties and functions related to it. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To investigate the association between couples’ communication before the wife’s death to cancer and the widower’s feelings of guilt and regret after the loss, in a population-based data. Methods: Men (n =907) younger than 80years and living in Sweden, who had lost their wives due to cancer, were asked 4–5years after their loss to answer an anonymous postal questionnaire it included questions about the couple’s end-of-life communication during the last 3months of life and the widower’s feelings of guilt or regret during the first 6months after the wife’s death. Results: During the last 3months of their wives’ lives, men who had not talked about the impending death with their wives had a higher risk of experiencing feelings of guilt than men who did talk (relative risk (RR) 2.0, 95% confidence interval [CI] 1.2–3.4). Men who were not able to spend as much time as they wished with their wives had an increase in the risk of having feelings of guilt twice that of men who spent time (RR 2.0 95% CI 1.5–2.7). Men who did not talk with their wives about how they could cope practically or emotionally after the death had elevated risks of guilt feelings compared with men who talked (RR 1.8, 95% CI 1.0–3.0; RR 1.7, 95% CI 1.0–2.9, respectively). Men who realised it was too late to discuss the impending death had an increased risk of guilt feelings (RR 4.3, 95% CI 2.9–6.6). Men who thought that not everything had been brought to closure before their wives’ deaths had 3.3 times increased risk of guilt feeling (RR 3.3, 95% CI 1.7–6.4). Conclusions: A man who does not have end-of-life discussions with his wife during the last 3months before her death from cancer may be subject to a significantly greater risk of experiencing feelings of guilt or regret in widowhood than men who did engage in such discussions. [Copyright &y& Elsevier]