Swedish National Inpatient Register Research Articles

EVALUATION OF THE SWEDEAMP DATABASE: FOCUS ON COVERAGE AND AMPUTATION LEVEL RATES

BACKGROUND: The National Board of Health and Welfare manages several national registers in Sweden. This includes the Swedish National Inpatient Register (IPR), covering all surgical operations, and SwedeAmp, focusing on outcomes after lower limb amputations (LLA). However, coverage rates of amputation levels between these registers have not been externally analyzed. OBJECTIVE: To compare SwedeAmp's coverage with IPR for LLA cases and to assess SwedeAmp's accuracy in capturing LLA data. The goal of this study was also to identify potential discrepancies and establish benchmarks for common amputation levels. METHODOLOGY: Data from both registers, covering the years 2018 to 2023, were compared regarding the amputation levels and patient demographics. The coverage rate of the SwedeAmp register was calculated using SwedeAmp data as the numerator and IPR data as the denominator. FINDINGS: The IPR registry recorded 10,788 LLAs across 21 regions (67 hospitals). The SwedeAmp documented 5,246 LLAs covering 17 regions (36 hospitals), leaving 5,542 amputations unaccounted for, mainly due to regions or hospitals not participating in the SwedeAmp registry and lower registration rates in some areas. Key findings include: Achieving full coverage in SwedeAmp (17 regions) would require registering 9,305 LLAs. Both men and women over 85 years were significantly underrepresented. Thirteen regions in SwedeAmp obtained more than 40% coverage rate. 5 regions had more than 50% rate of above-knee amputations (range: 50.9% - 68.2%). 8 regions reporting more than 50% rate of below-knee amputations (range: 53.1% - 88.9%). Among the 67 hospitals performing LLAs, 36 reported to SwedeAmp. Six of these hospitals performed fewer than 10 LLAs over a six-year period. CONCLUSION: SwedeAmp captured 48.6% of initial LLAs in Sweden, highlighting the need for improved data completeness in LLA records, especially as only 13 regions achieved over 40% Coverage. For hospitals performing regular amputation, the proposed benchmark - coverage of ≥60%, with ≤36.3% for transfemoral amputation (TF), ≤8.4% for knee disarticulations (KD), and ≥55.3% for transtibial amputations (TT) – could serve as a target to enhance consistency and accuracy in reporting. Expanding coverage can improve the register's utility in tracking outcomes, setting national standards, aiding research, and supporting clinical decision-making. Layman's Abstract The Swedish National Board of Health and Welfare manages different health records, including the Swedish National Inpatient Register (IPR), which tracks all surgeries, and SwedeAmp, which focuses on people who have had lower limb amputations. This study looked at how much of SwedeAmp’s data matches the IPR, aimed to identify differences and set standards for common types of amputations. We compared the levels of amputation and patient details between the two records to better understand their coverage. The IPR registered 10,788 lower limb amputations (LLAs) across 21 regions and 67 hospitals, while SwedeAmp reported 5,246 LLAs from 17 regions (36 hospitals), leaving 5,542 amputations unaccounted for. To achieve full coverage in SwedeAmp, 9,305 LLAs would need to be registered, representing 86.3% of all amputations in Sweden. Fewer men over 80 years and women over 85 years were included in the SwedeAmp registry compared to the IPR. Thirteen regions in SwedeAmp had a coverage rate of more than 40%. Five regions reported an above-knee amputation rate of over 50%, while eight regions had a below-knee amputation rate exceeding 50%. Among the 67 hospitals performing LLAs, 36 reported data to SwedeAmp. Six of these hospitals performed fewer than 10 LLAs over a six-year period. For hospitals performing regular amputations, a benchmark of ≥60% coverage, with ≤36.3% for transfemoral, ≤8.4% for knee disarticulations, and ≥55.3% for transtibial amputations, could improve consistency in reporting. Increasing SwedeAmp's participation would strengthen the reliability of national data, supporting better outcome tracking, research, and clinical standards. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/44089/33369 How To Cite: Johannesson A.G, Scheving R, Westlund k.L, Fridriksson T. Evaluation of the SwedeAmp database: Focus on coverage and amputation level rates. Canadian Prosthetics & Orthotics Journal. 2024; Volume 7, Issue 2, No.2. https://doi.org/10.33137/cpoj.v7i2.44089 Corresponding Author: Anton G. Johannesson, PhD, CPOÖssur Clinics EMEA, Stockholm, Sweden.E-Mail: ajohannesson@ossur.comORCID ID: https://orcid.org/0000-0001-8729-458X

Smoking and risk for morbidity and mortality in patients who undergoes coronary artery bypass grafting

Abstract Background The association between smoking and prognosis after coronary artery bypass grafting (CABG) is sparsley studied. The few previous studies investigating this association show conflicting results. Purpose The purpose was to explore the association between smoking and long-term risk for morbidity and mortality in patients undergoing CABG. Methods Data from the SWEDEHEART registry were used to identify all patients who underwent isolated CABG in Sweden from 1992 to 2020 and smoking status at time for surgery. Three other mandatory national registries were used to collect data for comorbidities, social factors, and death (Swedish National Inpatient Register, Longitudinal Integration Database for Health Insurance and Labor Market Studies and, Swedish Cause of Death Register). Cox regression models adjusted for age and sex, comorbidities and social factors were used to assess the risk for all cause death, stroke, myocardial infarction. Mean follow-up time was 5.2 years (range 0-10). Results In total, 27,434 patients aged >18 years were identified (18.2% women). The study population was divided into; never smoker (n=8593), former smoker (n=14666) and current smoker (n=4175). The proportion of previous ST Elevation Myocardial Infarction (STEMI), heart failure, previous stroke, peripheral vascular disease, chronic respiratory disease, depression, low education was higher in current smokers than in non-smokers. Compared to never smokers, current smokers had a higher risk for all-cause death (adjusted Hazard ratio (aHR) 1.36 (95% Confidence interval (CI) (1.22-1.52)) and stroke (aHR 1.39 (1.18-1.64)) but not for myocardial infarction (aHR 1.03 (0.87-1.21). Former smoker had higher risk for all cause death (aHR1.17 (1.08-1.28)) compared to never smokers but no increased risk for myocardial infarction 0.91 (0.81-1.03) and stroke (aHR 1.11 (0.98-1.25). Conclusion There is a strong association between smoking at the time for surgery and long-term risk for worse prognosis after CABG. The results emphasize the importance of encouraging and motivate CABG patients to smoking cessation.

Attention-Deficit/Hyperactivity Disorder Medications and Long-Term Risk of Cardiovascular Diseases

Use of attention-deficit/hyperactivity disorder (ADHD) medications has increased substantially over the past decades. However, the potential risk of cardiovascular disease (CVD) associated with long-term ADHD medication use remains unclear. To assess the association between long-term use of ADHD medication and the risk of CVD. This case-control study included individuals in Sweden aged 6 to 64 years who received an incident diagnosis of ADHD or ADHD medication dispensation between January 1, 2007, and December 31, 2020. Data on ADHD and CVD diagnoses and ADHD medication dispensation were obtained from the Swedish National Inpatient Register and the Swedish Prescribed Drug Register, respectively. Cases included individuals with ADHD and an incident CVD diagnosis (ischemic heart diseases, cerebrovascular diseases, hypertension, heart failure, arrhythmias, thromboembolic disease, arterial disease, and other forms of heart disease). Incidence density sampling was used to match cases with up to 5 controls without CVD based on age, sex, and calendar time. Cases and controls had the same duration of follow-up. Cumulative duration of ADHD medication use up to 14 years. The primary outcome was incident CVD. The association between CVD and cumulative duration of ADHD medication use was measured using adjusted odds ratios (AORs) with 95% CIs. Of 278 027 individuals with ADHD aged 6 to 64 years, 10 388 with CVD were identified (median [IQR] age, 34.6 [20.0-45.7] years; 6154 males [59.2%]) and matched with 51 672 control participants without CVD (median [IQR] age, 34.6 [19.8-45.6] years; 30 601 males [59.2%]). Median (IQR) follow-up time in both groups was 4.1 (1.9-6.8) years. Longer cumulative duration of ADHD medication use was associated with an increased risk of CVD compared with nonuse (0 to ≤1 year: AOR, 0.99 [95% CI, 0.93-1.06]; 1 to ≤2 years: AOR, 1.09 [95% CI, 1.01-1.18]; 2 to ≤3 years: AOR, 1.15 [95% CI, 1.05-1.25]; 3 to ≤5 years: AOR, 1.27 [95% CI, 1.17-1.39]; and >5 years: AOR, 1.23 [95% CI, 1.12-1.36]). Longer cumulative ADHD medication use was associated with an increased risk of hypertension (eg, 3 to ≤5 years: AOR, 1.72 [95% CI, 1.51-1.97] and >5 years: AOR, 1.80 [95% CI, 1.55-2.08]) and arterial disease (eg, 3 to ≤5 years: AOR, 1.65 [95% CI, 1.11-2.45] and >5 years: AOR, 1.49 [95% CI, 0.96-2.32]). Across the 14-year follow-up, each 1-year increase of ADHD medication use was associated with a 4% increased risk of CVD (AOR, 1.04 [95% CI, 1.03-1.05]), with a larger increase in risk in the first 3 years of cumulative use (AOR, 1.08 [95% CI, 1.04-1.11]) and stable risk over the remaining follow-up. Similar patterns were observed in children and youth (aged <25 years) and adults (aged ≥25 years). This case-control study found that long-term exposure to ADHD medications was associated with an increased risk of CVDs, especially hypertension and arterial disease. These findings highlight the importance of carefully weighing potential benefits and risks when making treatment decisions about long-term ADHD medication use. Clinicians should regularly and consistently monitor cardiovascular signs and symptoms throughout the course of treatment.

Osteoporosis-related fractures in men and women with established and early rheumatoid arthritis: predictors and risk compared with the general population

ObjectivesTo study the risk of osteoporosis-related fractures in a community-based sample of men and women with rheumatoid arthritis (RA) overall, as well as early (< 1 year of disease duration, follow-up time maximum 10 years) and established (RA diagnosis since ≥ 5 years on July 1, 1997) RA, compared with the general population. To study potential risk factors for fractures in patients with RA from baseline questionnaire data.MethodsA community-based cohort of patients with RA (n = 1928) was studied and compared to matched general population controls. Information on osteoporosis-related fractures (hip, proximal upper arm, distal forearm and vertebral fractures) during the period July 1, 1997 to December 31, 2017 was obtained by linkage to the Swedish National Inpatient Register and the Cause of Death Register. The incidence of fractures was estimated in patients and controls. Cox regression models were used to assess the relation between RA and the risk of fractures and to assess potential predictors of fractures in RA patients. Analyses were stratified by sex, and performed in all patients with RA, and in subsets with early and established RA.ResultsThe overall incidence of osteoporosis-related fractures in the RA cohort was 10.6 per 1000 person-years (95% CI 9.31; 12.0). There was an increased risk of fractures overall in both men (hazard ratio (HR) 1.55, 95% CI 1.03; 2.34) and women (HR 1.52; 95% CI 1.27; 1.83) with RA compared to controls, with significantly increased risk also in the hip. No increased risk of osteoporosis-related fractures overall was seen in patients with early RA (HR 1.01, 95% CI 0.69; 1.49). Higher age, longer duration of RA, higher HAQ scores and higher scores in the visual analogue scale for global health were predictors of fractures.ConclusionBoth men and women with RA were at increased risk of osteoporosis-related fractures. Patients with early RA did not have significantly increased risk during the first 10 years of disease in this study.

Treatment-Related Circulatory Diseases and Mortality in Hodgkin Lymphoma Patients Using Multi-State Modelling and Relative Survival

Introduction Diseases of the circulatory system (DCS) are some of the most common late effects of Hodgkin lymphoma (HL), primarily due to mediastinal radiotherapy and/or anthracycline-containing chemotherapy (e.g., ABVD and BEACOPP). As DCS is very common in the general population, modelling DCS attributable to HL therapy versus that expected in the general population is relevant to understand the magnitude of DCS reduction that could be achieved with less cardiotoxic therapies. This real-world data study used multi-state modelling and relative survival to estimate treatment-related DCS risk in HL survivors. Material and methods All HL patients registered in the Swedish Lymphoma Register 2000-2018, aged 18-80 years at diagnosis, and treated with anthracycline-containing therapy were included. DCS events were identified in the Swedish National Inpatient Register (ICD-10 codes I00-I99) and defined as the first admission for DCS after HL diagnosis. Sex-, year-, and age-specific DCS incidence rates in the general population were retrieved from public records. Patients were followed from treatment initiation through a series of states: alive and DCS-free, alive and with (excess or expected) DCS, dead without DCS, and dead after DCS. Follow-up ended on date of death, emigration, or December 31st, 2019, whichever came first. All state transitions were modelled separately using flexible parametric survival models, yielding hazard ratios (HR) with 95% confidence intervals (CI). A relative survival model incorporating the expected DCS rates was fitted to allow for estimation of excess DCS, which was then interpreted as treatment-related. Transition probabilities (i.e., the likelihood of being in a state) were predicted for specific patient groups, by sex and low/high (≤200/>200 mg/m2) cumulative anthracycline dose. Results In a total of 1,929 HL patients, the mean age at diagnosis was 42 years, 54% were males, and 49% were treated with high dose anthracycline (Table 1). The distribution of treatments was 66% ABVD, 20% CHOP-like, and 14% BEACOPP. During a median follow-up of 7.6 years (IQR: 4.5-11.0), 145 (7.5%) died without DCS, 377 patients (20%) were diagnosed with DCS, and 87 (5%) died after DCS. Figure 1a shows the sex-specific transition probabilities for a patient with advanced stage disease, diagnosed in 2000, at age 50, and treated with a cumulative anthracycline dose of >200mg/m2 in a ABVD regimen. The probability of being in the treatment-related (excess) DCS state at 10 years after first line treatment was 0.35 (95% CI: 0.09-0.75) for males and 0.41 (95% CI: 0.10-0.81) for females in this patient group. Figure 1b shows the probabilities for limited stage male patients diagnosed in 2000 at age 50, treated with ABVD, by low/high anthracycline dose. Here, the probability of being in the treatment-related (excess) DCS state at 10 years was 0.44 (95% CI: 0.16-0.76) and 0.53 (95% CI: 0.25-0.80) for low and high dose anthracycline patients, respectively. There were no significant differences in treatment-related (excess) DCS incidence rates or post DCS all-cause mortality rates (Table 1). Females had a significantly lower non-DCS mortality rate than males (adj. HR=0.69, 95% CI: 0.49-0.97), as did patients treated with high compared to low anthracycline dose (adj. HR=0.28, 95% CI: 0.18-0.44). Conclusion After 10 years, females had higher risks of treatment-related (excess) DCS compared to males, although not statistically significant and likely due to superior survival. The same was seen for high compared to low cumulative doses of anthracycline. Female sex and high dose anthracycline reduced the non-DCS mortality rate, but not the excess DCS incidence rate. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

ARTERIAL ELASTICITY PREDICTS CARDIOVASCULAR MORBIDITY AND MORTALITY- A LONGITUDINAL STUDY IN THE VARA-SKÖVDE COHORT

Objective: Background: Measures of arterial elasticity are used for early detection of vascular disease and identification of individuals at high risk for cardiovascular disease morbidity (CVD). Aim: To investigate the association between arterial elasticity and risk for CVD in men and women. Design and method: A total of 2816 randomly selected individuals were examined (Men = 1400) between 2002 and 2005. The average follow-up time was 14.8 ± 2.4 years. After excluding participants with known cardiovascular disease, hypertension and diabetes mellitus, 2362 individuals (Men = 1186) were included in this study. Small Arterial Elasticity Index (SAEI) was measured using the HDI/Pulse Wave™ CR2000. Diagnoses of CVD were defined as acute myocardial infarction or stroke and based on Swedish Cause of Death Register and Swedish National Inpatient Register for period 2002–2019. Kaplan – Meijer and Cox- regression analyses were used to investigate the differences between SAEI quartiles and future CVD, adjusting for age, sex, heart rate, systolic blood pressure, LDL- cholesterol, HOMA-IR, C- reactive protein, smoking, alcohol consumption and physical activity. Of note, higher values of SAEI indicate more compliant arteries. Results: Mean age at baseline was 46 ± 10.6 years. Overall, 108 events were observed, 38 in women with 11 under 50 years. In the fully adjusted model, a one quartile higher SAEI score was associated with a 26% lower risk of incident CVD among men and women combined; (HR = 0.74, 95% CI: 0.55- 0.99, p = 0.041). Similar results were observed in men in the fully adjusted model (HR = 0.65, 95% CI: 0.45- 0.95, p = 0.024). Analogous, however nonsignificant, results were observed in women older than 50 years (HR = 0.59, 95% CI: 0.24- 1.45). The effect size was significantly lower in women younger than 50 years (HR = 0.93, 95% CI: 0.58- 1.45). However, the number of events in this group was low. Conclusions: We showed a strong and independent association between SAEI and CVD in men. Similar tendencies and effect size were observed in postmenopausal women. The diastolic pulse wave appears to provide additional information for cardiovascular risk assessments.

Validation of the Swedish National Inpatient Register for the diagnosis of pulmonary embolism in 2005.

The Swedish National Inpatient Register (NPR) has near‐complete coverage of in‐hospital admissions and ICD codes in Sweden. Acute pulmonary embolism (PE) is a serious condition presenting challenges regarding diagnosis, treatment, and follow‐up. Here we aimed to validate the accuracy of acute PE diagnosis in the NPR, investigational findings, antithrombotic treatment, and follow‐up of PE patients in Sweden. From a nation‐wide cohort of all patients with in‐hospital diagnoses of acute PE (ICD‐10‐SE codes I26.0–I26.9) in 2005 (n = 5793), we selected those from two Swedish regions for thorough manual review of hospital records. We identified 599 patients with PE diagnoses according to the ICD‐10 coding system. We excluded 58 patients with admissions related to previous PE (47; 8%) or incorrect ICD codes (11; 2%), leaving 501 patients with probable PE diagnoses. We confirmed the diagnosis in 441 (79%) cases, which was based on imaging (435 patients; 73%) or autopsy (6; 1%). In the remaining 60 (11%) cases, the PE diagnosis was based on clinical findings and can therefore not be confirmed. Of the surviving patients with PE, 231 (47%) were offered follow‐up within 6 months after the acute event. At follow‐up, 67 patients (29%) had symptoms requiring clinical attention (dyspnoea or reduced general condition). The Swedish NPR showed acceptable accuracy for PE diagnosis, and could be reliably used for register‐based research regarding acute PE.

Trends in survival of Swedish men and women with heart failure from 1987 to 2014: a population-based case-control study.

AimsTo compare trends in short‐term and long‐term survival of patients with heart failure (HF) compared with controls from the general population.Methods and resultsWe used data from the Swedish National Inpatient Registry to identify all patients aged ≥18 years with a first recorded diagnosis of HF between 1 January 1987 and 31 December 2014 and compared them with controls matched on age and sex from the Total Population Register. We included 702 485 patients with HF and 1 306 183 controls. In patients with HF aged 18–64 years, short‐term (29 days to 6 months) and long‐term mortality (>11 years) decreased from 166 and 76.6 per 1000 person‐years in 1987 to 2000 to 99.6 and 49.4 per 1000 person‐years, respectively, in 2001 to 2014. During the same period, mortality improved marginally, in those aged ≥65 years: short‐time mortality from 368.8 to 326.2 per 1000 person‐years and long‐term mortality from 219.6 to 193.9 per 1000 person‐years. In 1987–2000, patients aged <65 years had more than three times higher risk of dying at 29 days to 6 months, with an hazard ratio (HR) of 3.66 [95% confidence interval (CI) 3.46–3.87], compared with controls (P < 0.0001) but substantially higher in 2001–2014 with an HR of 11.3 (95% CI 9.99–12.7, P < 0.0001). HRs for long‐term mortality (6–10 and >11 years) increased moderately from 2.49 (95% CI 2.41–2.57) and 3.16 (95% CI 3.07–3.24) in 1987–2000 to 4.35 (95% CI 4.09–4.63) and 4.11 (95% CI 3.49–4.85) in 2001–2014, largely because survival among controls improved more than that among patients with HF (P < 0.0001).ConclusionsAbsolute survival improved in HF patients aged <65 years, but only marginally so in those aged ≥65 years. Compared with controls, both short‐term and long‐term relative risk of dying increased, especially in younger patients with HF.

Electroconvulsive Therapy and the Risk of Suicide in Hospitalized Patients With Major Depressive Disorder

Electroconvulsive therapy (ECT) is indicated for severe depression, including depression with psychosis, catatonia, and/or an elevated suicide risk. However, the association of ECT with suicide risk is uncertain. To determine the association between ECT and the risk of suicide in patients with unipolar major depressive disorder. This registry-based cohort study used patient data from Swedish national registers. Patients with a record of inpatient care between January 1, 2012, and October 31, 2018, for moderate depression, severe depression, or severe depression with psychosis were included in the study. Propensity score matching (1:1) was used to balance risk factors for suicide at baseline between patients treated with and without ECT during the inpatient episode. Data from the Swedish National Quality Register for ECT and the Swedish National Inpatient Register were combined to identify patients who had received ECT during the inpatient episode. National registers were used to identify risk factors for suicide. Suicide within 3 and 12 months of admission to inpatient care was analyzed. Cox regression analyses were used to adjust for confounders. The study included 28 557 patients (mean [SD] age, ECT group, 55.9 [18.4] years; non-ECT group, 45.2 [19.2] years; 15 856 women [55.5%]). In the matched sample of 5525 patients in each group, 62 patients (1.1%) in the ECT group and 90 patients (1.6%) in the non-ECT group died of suicide within 12 months (hazard ratio [HR], 0.72; 95% CI, 0.52-0.99). Electroconvulsive therapy was significantly associated with a decreased risk of suicide in patients with psychotic features (HR, 0.20; 95% CI, 0.08-0.54) and those aged 45 to 64 years (HR, 0.54; 95% CI, 0.30-0.99) or 65 years or older (HR, 0.30; 95% CI, 0.15-0.59), but not in patients aged 44 years or younger (HR, 1.22; 95% CI, 0.68-2.16). The results of this cohort study support the continued use of ECT to reduce suicide risk in hospitalized patients who are severely depressed, especially those who are older than 45 years and those with a psychotic subtype.

The ASA score predicts infections, cardiovascular complications, and hospital readmissions after hip fracture - A nationwide cohort study

SummaryThis study examines the association between the ASA physical status classification score at hip fracture surgery and severe postoperative complications in patients aged 60 and older. Among both men and women, ASA scores consistently predict a wide range of complications including infections, cardiovascular complications, hospital readmissions, and death.IntroductionHip fractures are common in aging populations and associated with poor prognosis. This study examines how the American Society of Anaesthesiologists (ASA) physical status classification is related to severe complications among hip fracture patients including infections, cardiovascular diseases, hospital readmissions, and death.MethodsBased on a linkage of the Swedish National Inpatient Register with the Swedish National Registry for Hip Fractures (RIKSHÖFT), this study includes patients aged 60+ with first hip fracture between 1998 and 2017. We estimated associations between ASA score and complications during the hospital stay and during 1 year after hip fracture using multivariable-adjusted logistic regression and Cox proportional hazard regression.ResultsThe study population included 170,193 hip fracture patients of which 24% died and 39% were readmitted to hospital within 1 year. The most common complications were urinary tract infections, pneumonia, second hip fractures, and heart failure. Among both men and women, higher ASA scores were consistently associated with higher risks for all complications included in this study. The strongest associations were observed for heart failure, myocardial infarction, pneumonia, and death.ConclusionASA scores are routinely assessed in clinical practice and predict a wide range of postoperative complications among hip fracture patients. Since many complications may be preventable through adequate drug treatment, rehabilitation, and risk awareness, future studies should examine the mechanisms linking ASA scores to complication risk in order to improve preventive strategies. Particularly, the high risk of cardiovascular complications among patients with high ASA scores deserves clinical and scientific attention.

Dementia remains the major predictor of death among octogenarians. A study of two population cohorts of 85-year-olds examined 22\xa0years apart

Dementia is the major predictor of death in old age. The aim of this paper was to determine whether 8-year mortality among 85-year olds with and without dementia, and if the contribution of dementia to mortality relative to other common diseases has changed. We used two population-based cohorts of 85-year-olds (N = 1065), born in 1901–02 and 1923–24, which were examined with identical methods in 1986–87 and 2008–2010 and followed for 8-year mortality according to data from the Swedish Tax Agency. Dementia was diagnosed according to DSM-III-R. Other diseases were diagnosed based on self-reports, close informant interviews, somatic examinations, and the Swedish National In-patient Register. Compared to cohort 1901–02, cohort 1923–24 had a lower 8-year mortality both among those with (HR 0.7; 95% CI 0.5–0.99) and without dementia (HR 0.7; 95% CI 0.5–0.9). Dementia was associated with increased mortality in both cohorts (cohort 1901–02, HR 2.6; 95% CI 2.0–3.2, cohort 1923–24, HR 2.8; 95% CI 2.3–3.5), and remained the major predictor of death, with a population attributable risk of 31.7% in 1986–87 and 27.7% in 2008–10. Dementia remained the most important predictor of death in both cohorts. The relative risk for mortality with dementia did not change between cohorts, despite a decreased mortality rate in the population.

Incidence and Outcome of Popliteal Artery Injury Associated with Knee Dislocations, Ligamentous Injuries, and Close to Knee Fractures: A Nationwide Population Based Cohort Study

Arterial injury in knee trauma is rare but can be devastating if the diagnosis is delayed. The frequency of concomitant arterial injury resulting from knee dislocations remains unclear, and from knee fractures it remains unknown. The primary aim was to investigate the incidence of arterial injury in knee trauma requiring hospitalisation. Secondary aims were to identify risk factors and describe outcome. Traumatic popliteal artery injury and knee trauma were identified by International Classification of Diseases (ICD)-10 codes from the Swedish National Inpatient registry (NPR), 1998-2014 and linked with data using the unique personal identification number with the National Registry for vascular surgery (Swedvasc). Risk factors for popliteal artery injury (PAI) such as cause of injury, comorbidities and injury severity were extracted from the NPR. Socio-economic status data and population count came from Statistics Sweden, and cause and date of death from the Swedish Cause of Death Registry. A total of 71149 admissions due to all knee trauma were identified, and 359 with simultaneous PAIs. Some of those injuries were non-orthopaedic. The proportion of PAI after knee dislocation ranged between 3.4% (46/1370 dislocations or multiligamentous injuries) and 8.2% (46/564 dislocations), and 0.2% after fracture close to the knee (60/36483). The most common causes of injury with PAI were falls causing knee dislocations and motor vehicle accidents (MVAs) causing fractures. The fact that all 46 injuries occurring after multiligamentous injuries were classified as knee dislocations is probably explained by the fact that the ICD codes are chosen retrospectively when the patient leaves the hospital. PAI after knee dislocation is not uncommon, and most frequently caused by a fall. PAI associated with knee fracture is rare and mostly caused by a MVA, while in low energy knee fractures PAI is practically non-existent.

Blood pressure at the age of 70 as a predictor of incident dementia: A 15‐year longitudinal study

AbstractBackgroundWe have previously reported that blood pressure (BP) at age 70 predicted incident dementia in a birth cohort born 1901‐02. It is known that BP in older adults has decreased in high‐income countries during the last decades. The aim of this paper was to explore whether BP at age 70 still predicted incident dementia in a cohort born three decades later.MethodA population‐based sample of 70‐year‐olds born 1930 was followed for 15 years as part of the Gothenburg H70 Birth Cohort studies. Dementia was diagnosed by geriatric psychiatrists according to the DSM‐III‐R criteria at all examinations. All individuals with prevalent dementia at baseline were excluded in this study. Among drop‐outs, the Swedish National inpatient register was used to detect dementia. Systolic (SBP) and diastolic blood pressure (DBP) were measured at baseline and all follow‐ups. To compare the mean blood pressure levels between the groups, Students t‐tests were used.ResultAt baseline, 588 participants were free from dementia and 107 individuals developed dementia during the study period. Of these, 18 developed dementia between age 71‐75, 27 between 76‐80, and 62 between 81‐85. Those who developed dementia between age 76‐80 had higher mean SBP (165 [sd +21.9] versus 155 [sd +22.1], p=0.016), and DBP (90 [sd +10.7] versus 86 [sd +10.7] p=0.045) at age 70, compared to those who remained dementia‐free. There were no differences in SBP or DBP at age 70 among those who developed dementia between age 71‐75 or between age 81‐85.ConclusionOur results suggest that high blood pressure at the age of 70 predicts dementia incidence between age 76‐80 years, despite that mean BP was considerably lower in the later born cohort.

Measurable health effects associated with the daylight saving time shift.

The transition to daylight saving time (DST) is beneficial for energy conservation but at the same time it has been reported to increase the risk of cerebrovascular and cardiovascular problems. Here, we evaluate the effect of the DST shift on a whole spectrum of diseases-an analysis we hope will be helpful in weighing the risks and benefits of DST shifts. Our study relied on a population-based, cross-sectional analysis of the IBM Watson Health MarketScan insurance claim dataset, which incorporates over 150 million unique patients in the US, and the Swedish national inpatient register, which incorporates more than nine million unique Swedes. For hundreds of sex- and age-specific diseases, we assessed effects of the DST shifts forward and backward by one hour in spring and autumn by comparing the observed and expected diagnosis rates after DST shift exposure. We found four prominent, elevated risk clusters, including cardiovascular diseases (such as heart attacks), injuries, mental and behavioral disorders, and immune-related diseases such as noninfective enteritis and colitis to be significantly associated with DST shifts in the United States and Sweden. While the majority of disease risk elevations are modest (a few percent), a considerable number of diseases exhibit an approximately ten percent relative risk increase. We estimate that each spring DST shift is associated with negative health effects-with 150,000 incidences in the US, and 880,000 globally. We also identify for the first time a collection of diseases with relative risks that appear to decrease immediately after the spring DST shift, enriched with infections and immune system-related maladies. These diseases' decreasing relative risks might be driven by the documented boosting effect of a short-term stress (such as that experienced around the spring DST shift) on the immune system.

Validity of heart failure diagnoses made in 2000-2012 in western Sweden.

AimsThe aim of this study is to validate a diagnosis of heart failure (HF) according to the European Society of Cardiology (ESC) guidelines among patients hospitalized at Sahlgrenska University Hospital, Gothenburg, Sweden, between 2000 and 2012.Methods and resultsIn Sweden, it is mandatory to report all hospital discharge diagnoses to the Swedish national inpatient register. In total, 27 517 patients were diagnosed with HF at the Sahlgrenska University hospital between 2000 and 2012. Altogether, 1100 records with a primary (n = 550) or contributory (n = 550) diagnosis of HF were randomly selected. The diagnosis was validated according to the ESC guidelines from 1995, 2001, 2005, and 2008, and cases were divided into three groups: definite, probable, and miscoded. In total, 965 cases were validated, while 135 records were excluded for various reasons. Of the 965 records, the diagnosis was validated as definite in 601 (62.3%) and as probable in 310 (32.1%); only 54 (5.6%) of cases had been miscoded. Echocardiography, as an objective evidence of cardiac dysfunction, had been performed in 581 (96.7%) of the definite, 106 (34.2%) of the probable, and 31 (57.4%) of the miscoded cases. Among the probable cases, the main reason they had not been classified as a definitive diagnosis of HF was lack of examination by echocardiography (63.8%).ConclusionsThe overall validity of HF diagnosis at Sahlgrenska University Hospital is high. This may reflect a high diagnostic validity at the time of diagnosis in the national Swedish patient register, supporting the continued use of this register in epidemiological research.

Risk for hip fracture before and after total knee replacement in Sweden

SummaryWe studied the risk for hip fracture before and after total knee replacement (TKR) in the entire population in Sweden. Women and men had a low risk for hip fracture before TKR but an increased risk the first year after TKR.PurposeIt is known that osteoarthritis is associated with high bone mass. We therefore studied the risk of hip fracture before and after total knee replacement (TKR), risk of different hip fracture types, and risk subdivided in genders and age groups.MethodsWe followed the total Swedish population born between 1902 and 1952 (n = 4,258,934) during the period 1987–2002 and identified all patients with TKR due to primary OA (n = 39,291), and all patients with hip fracture (n = 195,860) in the Swedish National Inpatient Register. The risk time analyses were based on Poisson regression models.ResultsThe hazard ratio (HR) for hip fracture the last year before TKR was 0.86 (95% CI 0.74 to 1.00) and the first year after 1.26 (95% CI 1.11 to 1.42) compared to individuals without TKR. The HR for femoral neck fracture 0–10 years after TKR was 0.95 (95% CI 0.89 to 1.01) and for trochanteric fracture was 1.13 (95% CI 1.06 to 1.21). The HR for hip fracture in the age group 50–74 was 1.28 (95% CI 1.14 to 1.43) and in the age group 75–90 years was 0.99 (95% CI 0.94 to 1.04) 0–10 years after TKR, compared to individuals without TKR.ConclusionIndividuals had a low risk for hip fracture before TKR but an increased risk the first year after TKR. The risk in individuals below age 75 years and for trochanteric fractures was increased after TKR. Possible explanations include changed knee kinematics after a TKR, physical activity level, fall risk, and other unknown factors.

Increased early mortality and morbidity after total hip arthroplasty in patients with socioeconomic disadvantage: a report from the Swedish Hip Arthroplasty Register

Background and purpose — Socioeconomic status is associated with the outcome of major surgery. We investigated the association of socioeconomic status with the risk of early mortality and readmissions after primary total hip arthroplasty (THA).Patients and methods — We obtained information on income, education, immigration, and cohabiting status as well as comorbidities of 166,076 patients who underwent primary THA due to primary osteoarthritis (OA) from the Swedish Hip Arthroplasty Register, the Swedish National Inpatient Register and Statistics Sweden. Multivariable Cox regression models were fitted to estimate the adjusted risk of mortality or readmissions within 90 days after index surgery.Results — Compared with patients on a low income, the adjusted risk of 30-day mortality was considerably lower in patients on a high income (hazard ratio [HR] 0.5, 95% confidence interval [CI] 0.3–0.7) and in those on a medium income (HR 0.7, CI 0.6–0.9). Similar risk reductions were found for the endpoint 90-day mortality. Patients with a high income had a lower adjusted risk of readmission for cardiovascular reasons than those with a low income (HR 0.7, CI 0.6–0.9), as had those with a higher level of education (adjusted HR 0.7, CI 0.6–0.9). Patients with higher socioeconomic status had a lower degree of comorbidities than socioeconomically disadvantaged patients. However, adjusting for socioeconomic confounders in multivariable models only marginally influenced the predictive ability of the models, as expressed by their area under the curve.Interpretation — Income and level of education are strongly associated with early mortality and readmissions after primary THA, and both parameters are closely connected to health status. Since adjustment for socioeconomic confounders only marginally improved the predictive ability of multivariable regression models our findings indicate that comorbidities may under certain circumstances serve as an acceptable proxy measure of socioeconomic background.

Mortality in patients with permanent hypoparathyroidism after total thyroidectomy

Permanent hypoparathyroidism remains the most common adverse outcome after total thyroidectomy, but long-term effects of hypoparathyroidism are unknown. The aim was to investigate mortality in patients with permanent hypoparathyroidism after total thyroidectomy. Data from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery were linked with the Swedish National Prescription Register for Pharmaceuticals and the Swedish National Inpatient Register. Patients who underwent total thyroidectomy between 1 July 2005 and 30 June 2014 for benign thyroid disease, and who used active vitamin D for at least 6 months after surgery, were classified as having permanent hypoparathyroidism and included in the study cohort. Risk of death was assessed using Cox regression analysis, adjusting for age, sex, thyrotoxicosis and co-morbidity. There were 4899 patients, with a mean(s.d.) age of 46·3(15·8) years; 83·1 per cent were women, and 2932 patients (59·8 per cent) had thyrotoxicosis. In all, 246 patients (5·2 per cent) were classified as having permanent hypoparathyroidism. Mean(s.d.) follow-up was 4·4(2·4) years, and 109 patients (2·2 per cent) died during follow-up. Compared with patients without permanent hypoparathyroidism, the risk of death was significantly higher among patients with permanent hypoparathyroidism after total thyroidectomy (adjusted hazard ratio 2·09, 95 per cent c.i. 1·04 to 4·20). Permanent hypoparathyroidism after total thyroidectomy for benign disease is common and associated with an increased risk of death.

Cognitive performance in late adolescence and long-term risk of early heart failure in Swedish men.

AimsHeart failure (HF) incidence appears to increase among younger individuals, raising questions of how risk factors affect the younger population. We investigated the association of cognitive performance in late adolescence with long‐term risk of early HF.Methods and resultsWe followed a cohort of Swedish men enrolled in mandatory military conscription in 1968–2005 (n = 1 225 300; mean age 18.3 years) until 2014 for HF hospitalization, using data from the Swedish National Inpatient Registry. Cognitive performance (IQ) was measured through a combination of tests, separately evaluating logical, verbal, visuospatial, and technical abilities. The results were standardized, weighted, and presented as stanines of IQ. The association between IQ and risk of HF was estimated using Cox proportional hazards models. In follow‐up, there were 7633 cases of a first HF hospitalization (mean age at diagnosis 50.1 years). We found an inverse relationship between global IQ and risk of HF hospitalization. Using the highest IQ stanine as reference, the adjusted hazard ratio for the lowest IQ with risk of HF was 3.11 (95% confidence interval 2.60–3.71), corresponding to a hazard ratio of 1.32 (95% CI 1.28–1.35) per standard deviation decrease of IQ. This association proved persistent across predefined categories of HF with respect to pre‐existing or concomitant co‐morbidities; it was less apparent among obese conscripts (P for interaction =0.0004).ConclusionIn this study of young men, IQ was strongly associated with increased risk of early HF. The medical profession needs to be aware of this finding so as to not defer diagnosis.

Incidence, prevalence and seasonal onset variation of Addison's disease among persons with type 1 diabetes mellitus: nationwide, matched cohort studies.

We determined the incidence and prevalence of Addison's disease (AD) among persons with or without type 1 diabetes mellitus (T1DM) in nationwide, matched cohort studies. Persons with T1DM were identified from the Swedish National Diabetes Register and each was matched for age, sex, year and county to five controls randomly selected from the general population. Persons with AD were identified from the Swedish National Inpatient Register. Baseline demographics and seasonal onset variation of AD were presented by descriptive statistics. Prevalence and incidence were estimated by proportions and incidence rates, respectively. Times to AD were analyzed using the Cox proportional hazard model. Between 1998 and 2013, 66 persons with T1DM were diagnosed with AD at a mean age (s.d.) of 36.4 (13.0) years among 36 514 persons with T1DM, while 32 were diagnosed with AD at a mean age of 42.7 (15.2) years among 182 570 controls. The difference in mean age at diagnosis of AD between the groups was 6.3 years (P value = 0.036). The incidence of AD for a person with or without T1DM was therefore 193 and 18 per million person-years, respectively. The adjusted relative risk increase of developing AD in T1DM was 10.8 (95% CI: 7.1-16.5). The highest incidence of AD was observed during February-March and September-October. The prevalence of AD in persons with or without T1DM in December 2012 was 3410 and 208 per million, respectively. The odds ratio for AD in persons with T1DM vs controls was 16.5 (95% CI: 11.1-24.5). The risk to develop AD among persons with T1DM is more than 10 times higher than in persons without T1DM. Persons with T1DM develop AD at a younger age. The incidence of AD may have a seasonal pattern.