Early transfusion patterns improve the Molecular International Prognostic Scoring System (IPSS-M) prediction in myelodysplastic syndromes.

BACKGROUND: The Molecular International Prognostic Scoring System (IPSS-M) is the new gold standard for diagnostic outcome prediction in patients with myelodysplastic syndromes (MDS). This study was designed to assess the additive prognostic impact of dynamic transfusion parameters during early follow-up. METHODS: We retrieved complete transfusion data from 677 adult Swedish MDS patients included in the IPSS-M cohort. Time-dependent erythrocyte transfusion dependency (E-TD) was added to IPSS-M features and analyzed regarding overall survival and leukemic transformation (acute myeloid leukemia). A multistate Markov model was applied to assess the prognostic value of early changes in transfusion patterns. RESULTS: Specific clinical and genetic features were predicted for diagnostic and time-dependent transfusion patterns. Importantly, transfusion state both at diagnosis and within the first year strongly predicts outcomes in both lower (LR) and higher-risk (HR) MDSs. In multivariable analysis, 8-month landmark E-TD predicted shorter survival independently of IPSS-M (p < 0.001). A predictive model based on IPSS-M and 8-month landmark E-TD performed significantly better than a model including only IPSS-M. Similar trends were observed in an independent validation cohort (n = 218). Early transfusion patterns impacted both future transfusion requirements and outcomes in a multistate Markov model. CONCLUSION: The transfusion requirement is a robust and available clinical parameter incorporating the effects of first-line management. In MDS, it provides dynamic risk information independently of diagnostic IPSS-M and, in particular, clinical guidance to LR MDS patients eligible for potentially curative therapeutic intervention.

Risk of Postoperative Ischemic Stroke and Myocardial Infarction in Patients Operated for Cancer.

BACKGROUND: Risk assessment for ischemic stroke (IS) and myocardial infarction (MI) is done routinely before surgery, but the increase in risks associated with surgery is not known. The aim of this study is to assess the risk of arterial ischemic events during the first year after oncological surgery. METHODS: We used Swedish healthcare databases to identify 443,300 patients who underwent cancer surgery between 1987 and 2016 and 4,127,761 matched comparison subjects. We estimated odds ratios (ORs) for myocardial infarction and ischemic stroke during the hospitalization with logistic regression and calculated 1-year cumulative incidences and hazard ratios (HRs) with 95% confidence intervals (CIs) for the outcomes after discharge. RESULTS: The cumulative incidences of myocardial infarction and ischemic stroke during the first postoperative year were 1.33% and 1.25%, respectively. In the comparison cohort, the corresponding 1-year cumulative incidences were 1.04% and 1.00%. During the hospitalization, the OR for myocardial infarction was 8.81 (95% CI 8.24-9.42) and the OR for ischemic stroke was 6.71 (95% CI 6.22-7.23). After discharge, the average HR during follow-up for 365 days was 0.90 (95% CI 0.87-0.93) for myocardial infarction and 1.02 (95% CI 0.99-1.05) for ischemic stroke. CONCLUSIONS: We found an overall increased risk of IS and MI during the first year after cancer surgery that was attributable to events occurring during the hospitalization period. After discharge from the hospital, the overall risk of myocardial infarction was lower among the cancer surgery patients than among matched comparison subjects.

Risk of recurrent red-cell transfusion in delivery: A nationwide longitudinal study.

OBJECTIVE: To investigate the risk of recurrent maternal red-cell transfusion in delivery. DESIGN: Nationwide long-standing retrospective cohort study. SETTING: Swedish medical birth register. POPULATION: All registered births from 2000 to 2017 in Sweden. METHODS: We included all women with between one and three consecutive registered births from 22 weeks of gestation onwards and all maternal red-cell transfusions in the peripartum period within the defined period of study. Information on gestational and non-gestational comorbidity was collected and we identified any female siblings. In our analyses we compared the risk of red-cell transfusion in delivery in relation to transfusion history and gestational and non-gestational comorbidity. MAIN OUTCOME MEASURES: Maternal peripartum red-cell transfusion, defined as a recorded transfusion in the period from 1 day before and 7 days after delivery. RESULTS: We included 825 451 women with a total 1 419 909 deliveries, including 786 097 (55.4%) first, 511 398 (36.0%) second and 122 414 (8.6%) third deliveries. Of women with previous obestric transfusion, 8.7% were transfused in a second delivery, compared with 1.7% of women without transfusion or diagnosis of haemorrhage. A previous diagnosis of haemorrhage did not affect the odds ratio of transfusion recurrence. Among women who were transfused in their first two deliveries, 15.5% were transfused in third delivery, corresponding to an 11-fold increase, compared with non-transfused women (adjusted odds ratio aOR 11.5, 95% CI 7.9-16.6). Women with a sister transfused in delivery were at increased risk of transfusion in a second delivery (aOR 1.8, 95% CI 1.6-2.1). CONCLUSIONS: Women with previous red-cell transfusion are at an increased risk of red-cell transfusion in a subsequent delivery, compared with women without a history of red-cell transfusion.

Management and outcomes of patients with chest pain and psychiatric disorders in the era of high-sensitivity cardiac troponins.

BACKGROUND: The management of patients with psychiatric disease and chest pain in the emergency department (ED) in the era of high-sensitivity cardiac troponin assays is unexplored. OBJECTIVES: To investigate differences in management and outcomes comparing patients with versus without psychiatric disorders who present with chest pain in the ED. METHODS: All visits to seven different EDs in Sweden from 9 December 2010 to 31 December 2016 by patients with chest pain were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate differences in clinical management. Hazard ratios with 95% CIs were used for comparisons of all-cause mortality and risk of cardiovascular events. RESULTS: Altogether, 216,653 visits were identified, of which 40,054 (18%) occurred in patients with psychiatric disorders. The risk of a myocardial infarction (MI) was reduced almost by half in patients with an affective (OR 0.63; 95% CI: 0.59-0.68) or psychotic disorder (OR 0.57; 95% CI: 0.47-0.70). These patients were less likely to be treated with any cardiovascular medication or to undergo percutaneous coronary intervention. Contrastingly, patients with psychiatric disease had a 1.8- to 2.6-fold increased risk of being diagnosed with an MI registered after the index visit but within 30 days. CONCLUSIONS: Patients with psychiatric disease and chest pain undergo less intense investigation and are less likely to receive cardiovascular medications compared with patients without psychiatric disease, even in the presence of myocardial injury. In addition, they experience a higher risk of being diagnosed with an MI within 30 days after a visit with no MI.

A population-based, retrospective cohort study of the association between ABO blood group and risk of COVID-19.

BACKGROUND: Several studies have investigated associations between ABO blood group and risk of COVID-19, with inconsistent results. OBJECTIVE: To study associations between ABO blood group and risk of different stages of COVID-19. METHODS: The study was based on nationwide registers encompassing all blood-grouped persons in Sweden, and all of their COVID-19-related outcomes. Associations between ABO blood group and COVID-19 outcomes were estimated using Poisson regression models. Analyses were conducted overall and stratified by vaccination status. RESULTS: A total of 4,986,878 individuals were included. The incidence rate ratios of testing positive for COVID-19 were 1.08 (95% confidence interval [CI], 1.07-1.08), 1.06 (95% CI, 1.05-1.07), and 1.01 (95% CI, 1.00-1.01) for blood groups A, AB, and B, respectively, as compared to O. Similar associations were seen for risk of hospital admissions, intensive care unit admissions, and risk of death. For most outcomes, associations with ABO blood group were much attenuated or even reversed in vaccinated individuals. CONCLUSIONS: Individuals with blood groups A, AB, and B are at increased risk of contracting COVID-19 as well as developing more severe forms of the disease.

Red blood cell alloimmunization in myelodysplastic syndromes: Associations with sex, DAT-positivity, and increased transfusion needs.

BACKGROUND: Many patients with myelodysplastic syndromes (MDS) need repeated red blood cell transfusions which entails a risk of immunization and antibody formation. Associations between alloantibodies, autoantibodies and increased transfusion requirements have been reported, but their relationship remains unclear. In this study, we analyzed factors potentially associated with red blood cell alloimmunization, as well as changes in transfusion intensity and post-transfusion hemoglobin increments. METHODS: In a retrospective cohort study, we linked Swedish MDS patients diagnosed between 2003 and 2017 to transfusion and immunohematology data. Potentially associated factors were analyzed using Cox proportional hazards regression. The transfusion rate after detected alloimmunization was analyzed using a fixed effects Poisson regression. Post-transfusion hemoglobin increments before and after alloimmunization were compared using a mixed effects regression. RESULTS: Alloantibodies following MDS diagnosis were detected in 50 out of 429 patients (11.7%). Female sex and a positive direct antiglobulin test (DAT) were independently associated with alloimmunization, with hazard ratios of 2.02 (95% confidence interval [CI] 1.08-3.78) and 9.72 (95% CI, 5.31-17.74), respectively. The transfusion rate following alloimmunization was increased with an incidence rate ratio of 1.33 (95% CI, 0.98-1.80) and the post-transfusion hemoglobin increment after alloimmunization was 1.40 g/L (95% CI, 0.52-2.28) lower per red blood cell unit (p = .002) compared to before alloimmunization, in multivariable analyses. DISCUSSION: Alloimmunization against blood group antigens was associated with sex, DAT-positivity, increased transfusion needs, and lower post-transfusion hemoglobin increments. These findings warrant further investigation to evaluate the clinical significance of up-front typing and prophylactic antigen matching in patients with MDS.

Intracerebral Hemorrhage Among Blood Donors and Their Transfusion Recipients.

Importance: Recent reports have suggested that cerebral amyloid angiopathy, a common cause of multiple spontaneous intracerebral hemorrhages (ICHs), may be transmissible through parenteral injection of contaminated cadaveric pituitary hormone in humans. Objective: To determine whether spontaneous ICH in blood donors after blood donation is associated with development of spontaneous ICH in transfusion recipients. Design, Setting, and Participants: Exploratory retrospective cohort study using nationwide blood bank and health register data from Sweden (main cohort) and Denmark (validation cohort) and including all 1 089 370 patients aged 5 to 80 years recorded to have received a red blood cell transfusion from January 1, 1970 (Sweden), or January 1, 1980 (Denmark), until December 31, 2017. Exposures: Receipt of red blood cell transfusions from blood donors who subsequently developed (1) a single spontaneous ICH, (2) multiple spontaneous ICHs, or (3) no spontaneous ICH. Main Outcomes and Measures: Spontaneous ICH in transfusion recipients; ischemic stroke was a negative control outcome. Results: A total of 759 858 patients from Sweden (median age, 65 [IQR, 48-73] years; 59% female) and 329 512 from Denmark (median age, 64 [IQR, 50-73] years; 58% female) were included, with a median follow-up of 5.8 (IQR, 1.4-12.5) years and 6.1 (IQR, 1.5-11.6) years, respectively. Patients who underwent transfusion with red blood cell units from donors who developed multiple spontaneous ICHs had a significantly higher risk of a single spontaneous ICH themselves, compared with patients receiving transfusions from donors who did not develop spontaneous ICH, in both the Swedish cohort (unadjusted incidence rate [IR], 3.16 vs 1.12 per 1000 person-years; adjusted hazard ratio [HR], 2.73; 95% CI, 1.72-4.35; P < .001) and the Danish cohort (unadjusted IR, 2.82 vs 1.09 per 1000 person-years; adjusted HR, 2.32; 95% CI, 1.04-5.19; P = .04). No significant difference was found for patients receiving transfusions from donors who developed a single spontaneous ICH in the Swedish cohort (unadjusted IR, 1.35 vs 1.12 per 1000 person-years; adjusted HR, 1.06; 95% CI, 0.84-1.36; P = .62) nor the Danish cohort (unadjusted IR, 1.36 vs 1.09 per 1000 person-years; adjusted HR, 1.06; 95% CI, 0.70-1.60; P = .73), nor for ischemic stroke as a negative control outcome. Conclusions and Relevance: In an exploratory analysis of patients who received red blood cell transfusions, patients who underwent transfusion with red blood cells from donors who later developed multiple spontaneous ICHs were at significantly increased risk of spontaneous ICH themselves. This may suggest a transfusion-transmissible agent associated with some types of spontaneous ICH, although the findings may be susceptible to selection bias and residual confounding, and further research is needed to investigate if transfusion transmission of cerebral amyloid angiopathy might explain this association.

The frequency of misattributed paternity in Sweden is low and decreasing: A nationwide cohort study.

BACKGROUND: The occurrence of misattributed paternity has consequences throughout society with implications ranging from inheritance and royal succession to transplantation. However, its frequency in Sweden is unknown. OBJECTIVE: To estimate the contemporary frequency of misattributed paternity in Sweden. METHODS: The study was based on nationwide ABO blood group data and a nationwide register of familial relationships in Sweden. These data were analysed using both a frequentist Poisson model and the Bayesian Gibbs model. The conduct of the study was approved by the regional ethics committee in Stockholm, Sweden (reference numbers 2018/167-31 and 2019-04656). RESULTS: Nearly two million mother-father-offspring family units were included. Overall, the frequency of misattributed paternity was estimated at 1.7% in both models. Misattributed paternity was more common among parents with low educational levels, and has decreased over time to a current 1%. CONCLUSIONS: The misattributed paternity rate is similar to the rates in other West European populations. Apart from widespread societal implications, studies on heritability may consider misattributed paternity as a minor source of error.

Patterns and determinants of blood transfusion in intensive care in Sweden between 2010 and 2018: A nationwide, retrospective cohort study.

BACKGROUND: Intensive care unit (ICU) patients are transfused with blood products for a number of reasons, from massive ongoing hemorrhage, to mild anemia following blood sampling, combined with bone marrow depression due to critical illness. There's a paucity of data on transfusions in ICUs and most studies are based on audits or surveys. The aim of this study was to provide a complete picture of ICU-related transfusions in Sweden. METHODS: We conducted a register based retrospective cohort study with data on all adult patient admissions from 82 of 84 Swedish ICUs between 2010 and 2018, as recorded in the Swedish Intensive Care Register. Transfusions were obtained from the SCANDAT-3 database. Descriptive statistics were computed, characterizing transfused and nontransfused patients. The distribution of blood use comparing different ICUs was investigated by computing the observed proportion of ICU stays with a transfusion, as well as the expected proportion. RESULTS: In 330,938 ICU episodes analyzed, at least one transfusion was administered for 106,062 (32%). For both red-cell units and plasma, the fraction of patients who were transfused decreased during the study period from 31.3% in 2010 to 24.6% in 2018 for red-cells, and from 16.6% in 2010 to 9.4% in 2018 for plasma. After adjusting for a range of factors, substantial variation in transfusion frequency remained, especially for plasma units. CONCLUSION: Despite continuous decreases in utilization, transfusions remain common among Swedish ICU patients. There is considerable unexplained variation in transfusion rates. More research is needed to establish stronger critiera for when to transfuse ICU patients.

Adverse outcomes in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors: Follow-up of patients diagnosed 2002-2017 in a complete coverage and nationwide agnostic register study.

Tyrosine kinase inhibitors (TKIs) have profoundly improved the clinical outcome for patients with chronic myeloid leukemia (CML), but their overall survival is still subnormal and the treatment is associated with adverse events. In a large cohort-study, we assessed the morbidity in 1328 Swedish CML chronic phase patients diagnosed 2002-2017 and treated with TKIs, as compared to that in carefully matched control individuals. Several Swedish patient registers with near-complete nationwide coverage were utilized for data acquisition. Median follow-up was 6 (IQR, 3-10) years with a total follow-up of 8510 person-years for the full cohort. Among 670 analyzed disease categories, the patient cohort showed a significantly increased risk in 142 while, strikingly, no category was more common in controls. Increased incidence rate ratios/IRR (95% CI) for more severe events among patients included acute myocardial infarction (AMI) 2.0 (1.5-2.6), heart failure 2.6 (2.2-3.2), pneumonia 2.8 (2.3-3.5), and unspecified sepsis 3.5 (2.6-4.7). When comparing patients on 2nd generation TKIs vs. imatinib in a within-cohort analysis, nilotinib generated elevated IRRs for AMI (2.9; 1.5-5.6) and chronic ischemic heart disease (2.2; 1.2-3.9), dasatinib for pleural effusion (11.6; 7.6-17.7) and infectious complications, for example, acute upper respiratory infections (3.0; 1.4-6.0). Our extensive real-world data reveal significant risk increases of severe morbidity in TKI-treated CML patients, as compared to matched controls, particularly for 2nd generation TKIs. Whether this increased morbidity may also translate into increased mortality, thus preventing CML patients to achieve a normalized overall survival, needs to be further explored.

Effect of anticoagulant and platelet inhibition on the risk of bacteremia among patients with acute pyelonephritis: a retrospective cohort study.

BACKGROUND: An increasing number of patients are being prescribed anticoagulants and platelet inhibitors (antithrombotic treatment). Basic research has suggested an association between antithrombotic treatment and bacteremia during kidney infection. Here, we investigated the association between antithrombotic treatment, bacteremia and acute kidney injury in patients with acute pyelonephritis. METHODS: A retrospective cohort study was conducted in a large university hospital in Sweden. Data were retrieved from electronic medical records for adult patients with acute pyelonephritis in 2016. The main outcome was bacteremia and secondary outcome acute kidney injury. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated through multiple logistic regression. Treatment with different groups of antithrombotic agents were compared to no antithrombotic treatment. RESULTS: 1814 patients with acute pyelonephritis were included, in whom bacteremia developed in 336 (18.5%). Low-molecular-weight heparin (LMWH) at prophylactic doses was associated with a lower risk of bacteremia, compared to no antithrombotic treatment (OR 0.5; 95% CI 0.3-0.7). Other antithrombotic treatments were not associated with a risk of bacteremia. Additionally, patients with prophylactic doses of LMWH had a lower risk of acute kidney injury (OR 0.5; 95% CI 0.3-0.8). CONCLUSIONS: We found no association between antithrombotic treatment and an increased risk of bacteremia during acute pyelonephritis. Conversely, patients with prophylactic doses of LMWH had a slightly reduced risk of bacteremia. LMWH at prophylactic doses was also associated with a lower risk of acute kidney injury. Our results suggest that it is safe to continue antithrombotic treatment during acute pyelonephritis, in regards to bacteremia and acute kidney injury risk.

Short-term health outcomes following whole blood donation: A nationwide, retrospective cohort study.

BACKGROUND: Blood donation is associated with a number of adverse events. Most of these are both uncommon and nonsevere, leading to mild discomfort for the donor at worst. However, adverse events occurring outside of the donation facility have largely not been studied. In this study, we aim to further the understanding by performing the first large-scale analysis of short-term risks following whole blood donation. METHODS: We set up a nationwide cohort of donors who donated whole blood between 1987 and 2018. Analyses were conducted using conditional logistic regression in a self-comparison design, where each donor was compared only to themselves, considering the 30-day risk of 16 outcomes following whole blood donation. Outcomes included cardiac/vascular diseases such as myocardial infarction, unspecified conditions such as fainting, accidents or external causes of injury, and death. RESULTS: A total of 963,311 donors were included; of whom, 19,670 experienced at least one of the outcomes within 30 days of a blood donation. For fainting and hypotonia, we observed transient 2- to 5-fold risk increases on the day of donation and the subsequent 2-3 days. Importantly, the risk increase for the most pronounced effect corresponded to less than one additional events of fainting per 200,000 blood donations. Risks of all other outcomes were either unaffected or lower than expected right after blood donation. DISCUSSION: To conclude, we found no evidence of new or unexpected short-term health effects after blood donation and confirmed that risks of hypotension-related events requiring hospital care are present but small.

Frequent platelet donation is associated with lymphopenia and risk of infections: A nationwide cohort study.

BACKGROUND: Recently, plateletpheresis donations using a widely used leukoreduction system (LRS) chamber have been associated with T-cell lymphopenia. However, clinical health consequences of plateletpheresis-associated lymphopenia are still unknown. STUDY DESIGN AND METHODS: A nationwide cohort study using the SCANDAT3-S database was conducted with all platelet- and plasmapheresis donors in Sweden between 1996 and 2017. A Cox proportional hazards model, using donations as time-dependent exposures, was used to assess the risk of infections associated with plateletpheresis donations using an LRS chamber. RESULTS: A total of 74 408 apheresis donors were included. Among donors with the same donation frequency, plateletpheresis donors using an LRS chamber were at an increased risk of immunosuppression-related infections and common bacterial infections in a dose-dependent manner. While very frequent donors and infections were rare in absolute terms resulting in wide confidence intervals (CIs), the increased risk was significant starting at one-third or less of the allowed donation frequency in a 10-year exposure window, with hazard ratios reaching 10 or more. No plateletpheresis donors that used an LRS chamber experienced a Pneumocystis jirovecii, aspergillus, disseminated mycobacterial, or cryptococcal infection. In a subcohort (n = 42), donations with LRS were associated with low CD4+ T-cell counts (Pearson's R = -0.41; 95% CI, - 0.63 to -0.12). CONCLUSION: Frequent plateletpheresis donation using an LRS chamber was associated with CD4+ T-cell lymphopenia and an increased risk of infections. These findings suggest a need to monitor T-lymphocyte counts in frequent platelet donors and to conduct future investigations of long-term donor health and for regulators to consider steps to mitigate lymphodepletion in donors.

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.

Costs associated with transfusion therapy in patients with myelodysplastic syndromes in Sweden: a nationwide retrospective cohort study.

BACKGROUND AND OBJECTIVES: Blood transfusion is a cornerstone therapy for many patients with myelodysplastic syndromes (MDS), but ranges from few to no transfusions to intensive transfusion therapy. To date, no large studies have described transfusion use or costs for patients with MDS, accounting for the range of disease severity. MATERIALS AND METHODS: A nationwide cohort study was conducted with all patients diagnosed with MDS in Sweden between 2008 and 2017, based on the Swedish MDS register and the Swedish part of the Scandinavian Donations and Transfusions Database 3 (SCANDAT3-S). Patients were followed from diagnosis until death, emigration, allogeneic hematopoietic stem cell transplantation or end of follow-up. Average cumulative transfusion count and costs over time were calculated, stratified by the revised international prognostic scoring system (IPSS-R) and age at diagnosis. Costs calculations used data on incident transfusions and laboratory testing and were divided into: direct material costs, direct labour costs and laboratory costs. RESULTS: In total, 2311 patients were included in the cohort. In the first four years after diagnosis, patients in the very low IPSS-R category received on average 25 red cell (95% confidence interval, 20-32) and 4 (3-7) platelet transfusions. Conversely, patients in the very high-risk category received on average 171 (135-200) red cell and 66 (51-78) platelet transfusions. Correspondingly, transfusion costs ranged from $8805 ($6482-$11 625) to $80 106 ($61 460-$95 792). CONCLUSION: Transfusion count and costs for patients with MDS increased markedly with IPSS-R risk category, but were similar across age groups. Transfusion costs were considerable for the highest IPSS-R risk categories.

Patterns of red-cell transfusion use in obstetric practice in sweden 2003-2017: A nationwide study.

BACKGROUND: There is a paucity of data on patterns of red-cell transfusions in obstetrical care, but some studies have suggested an increase in transfusion rates during the last decade. The purpose of this study was to investigate maternal characteristics, temporal trends and hospital variations in red-cell use in a large contemporary obstetric cohort in Sweden. STUDY DESIGN AND METHODS: Nationwide observational cohort study of maternal red-cell transfusions for all deliveries in Sweden between 2003 and 2017. RESULTS: The proportion of deliveries that received red-cell transfusions was stable during the study period, although the number of red-cell units administered per delivery declined. Among transfused women, most received a low-volume transfusion of 1 or 2 units. Red-cell transfusion was more common among the nulliparous, for instrumental and caesarean deliveries, and with increased maternal age. We saw large variations in transfusion rates between hospitals in Sweden, despite adjusting for age and parity. CONCLUSIONS: In comparison to other high-resource countries we see a high proportion of deliveries with maternal red-cell transfusions. However, we do not see an increase in red-cell use over time.

Red blood cell transfusion does not increase risk of venous or arterial thrombosis during hospitalization.

Previous observational studies suggest associations between red blood cell (RBC) transfusion and risk for arterial or venous thrombosis. We determined the association between thrombosis and RBC transfusion in hospitalized patients using the Recipient Database from the National Heart Lung and Blood Institute (NHLBI) Recipient Epidemiology and Donor Evaluation Study-III. A thrombotic event was a hospitalization with an arterial or venous thrombosis ICD-9 code and administration of a therapeutic anticoagulant or antiplatelet agent. Patients with history of thrombosis or a thrombosis within 24 hours of admission were excluded. A proportional hazards regression model with time-dependent covariates was calculated. Estimates were adjusted for age, sex, hospital, smoking, medical comorbidities, and surgical procedures. Of 657 412 inpatient admissions, 67 176 (10.2%) received at least one RBC transfusion. Two percent (12927) of patients experienced a thrombosis. Of these, 2587 developed thrombosis after RBC transfusion. In unadjusted analyses, RBC transfusion was associated with an increased thrombosis risk [HR = 1.3 (95% CI 1.23-1.36)]. After adjustment for surgical procedures, age, sex, hospital, and comorbidities, no association between RBC transfusion on risk of venous and arterial thrombosis was found [HR 1.0 (95% CI: 0.96-1.05)]. Thus, RBC transfusion does not appear to be an important risk factor for thrombosis in most hospitalized patients.

Accuracy of postpartum hemorrhage coding in the Swedish Pregnancy Register.

INTRODUCTION: Postpartum hemorrhage (PPH) is recognized as a leading cause of obstetric morbidity and mortality. Population-wide studies have used International Classification of Diseases (ICD) diagnostic codes to track and report the prevalence of PPH. Although the 10th revision (ICD-10) was introduced in Sweden in 1997, the accuracy of ICD-10 codes for PPH is not known. Thus, the aim was to determine the accuracy of diagnostic coding for PPH in the Swedish Pregnancy Register. MATERIAL AND METHODS: We performed a retrospective cohort study of 609 807 deliveries in Sweden between 2014 and 2019. Information on ICD-10 codes for PPH and estimated blood loss were extracted from the Swedish Pregnancy Register. Using an estimated blood loss >1000 mL as the reference standard, we evaluated the diagnostic accuracy of ICD-10 codes for PPH by estimating sensitivity, specificity, positive predictive value and negative predictive value with exact binomial 95% confidence intervals (CIs). In our secondary analysis, we assessed the ICD-10 coding accuracy for severe PPH, defined as an estimated blood loss >1000 mL and transfusion of at least 1 unit of red blood cells registered in the Scandinavian Donations and Transfusion database. RESULTS: Of the 609 807 deliveries, 43 312 (7.1%) had an ICD-10 code for PPH and 45 071 (7.4%) had an estimated blood loss >1000 mL. The ICD codes had a sensitivity of 88.5% (95% CI 88.2-88.7), specificity of 99.4% (95% CI 99.4-99.4), positive predictive value of 92.0% (95% CI 91.8-92.3) and negative predictive value of 99.1% (95% CI 99.1-99.1). In our secondary analysis, on deliveries with severe PPH, the sensitivity for an ICD code was 91.3% (95% CI 90.7-91.9), whereas specificity was 83.5% (95% CI 82.3-84.6). CONCLUSIONS: Our findings indicate that ICD-10 codes for PPH in Sweden have moderately high sensitivity and excellent specificity. These results suggest that PPH diagnostic codes in medical records and linked pregnancy and birth registers can be used for research, quality improvement and reporting PPH prevalence in Sweden.

The Swedish Scandinavian donations and transfusions database (SCANDAT3-S) - 50 years of donor and recipient follow-up.

BACKGROUND: The two previous versions of the Scandinavian donations and transfusions (SCANDAT) databases, encompassing data on blood donors, blood components, transfusions, and transfused patients linked to national health registers in Sweden and Denmark up until 2012, have been used to study donor health, disease transmission, the role of donor characteristics, and more. STUDY DESIGN AND METHODS: Here we describe the creation of the Swedish portion of the third iteration of SCANDAT - SCANDAT3-S - with follow-up from 1968 to the end of 2017, resulting in up to 50 years of uninterrupted follow-up for donors and recipients. The database now also includes non-transfused non-donors with a blood typing result, increased temporal resolution for transfusions, and linkages to laboratory and drug prescription data. RESULTS: After data cleaning, the database contained 23 579 863 donation records, 21 383 317 transfusion records, and 8 071 066 unique persons with valid identification. In total, the database offers 28 638 436 person-years of follow-up for donors, 13 582 350 person-years of follow-up for transfusion recipients, and 65 613 639 person-years of follow-up for non-recipient non-donors, with possibility for future extension. Additionally, the database includes 167 820 412 dispense records for prescribed drugs and 316,338,442 laboratory test results. Since the latest update in 2012, >99.9% of all donations were traceable to a donor with valid identification, and >97% of all transfusions to a recipient with valid identification. CONCLUSION: With extended follow-up and more clinical detail, the Swedish portion of the third and latest iteration of the SCANDAT database should allow for more comprehensive analysis of donation and transfusion-related research questions.

Risk of hematological malignancy in blood donors: A nationwide cohort study.

BACKGROUND: There has been a concern that blood donations can increase the risk of hematological malignancies. We investigated if blood donations increase the risk of developing hematological malignancies, specifically acute lymphoblastic leukemia, acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myeloid leukemia, Hodgkin lymphoma, and myeloma, as well other non-Hodgkin lymphoma. STUDY DESIGN AND METHODS: In total, the study included 1,021,433 Swedish blood donors, with 19.5 million person-years of follow-up. Two sets of analysis were performed. In the first cohort analysis, standardized incidence ratios (SIRs) were calculated, comparing the incidence of the different types of hematological cancers in blood donors to that of the general population. In the second analysis, a nested case-control study was conducted, investigating the association between number of donations and the risk of each type of malignancy. RESULTS: Apart from a modestly elevated risk of CLL (SIR, 1.07; 95% confidence interval [CI], 1.01-1.15) and a modestly decreased risk of AML (SIR, 0.85; 95% CI, 0.77-0.83), the risk of hematological malignancies did not differ between blood donors and the general population. In the nested case-control study there were no convincing associations between number of prior whole blood donations and site-specific malignancy risk. CONCLUSIONS: There was no convincing evidence of an increased risk in any hematological malignancy when interpreting the results from both series of analyses.