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SUMMARY: With the development of several 'vein‐to‐vein' databases, which capture data on the entire donor–recipient continuum and link this data to health outcomes, there has been an increasing number of studies investigating the health effects of all aspects of the practice of transfusion medicine. The Scandinavian Donations and Transfusions (SCANDAT) database is one of several such databases, which includes all electronically available data on blood donors, donations and transfusions since the late 1960s in Sweden and the early 1980s in Denmark. The SCANDAT database has been used to characterise disease occurrence among blood donors and transfused patients, as well as to investigate possible health effects of blood donations, aspects of transfusion care and possible transfusion transmission of disease. Recent publications include studies on recipient mortality associated with the storage lesion, studies on the effects of donor demographics on patient mortality and health effects of frequent blood donation. Although this research approach is clearly very powerful, the appropriate analysis of such real‐world data is complex and requires close methodological attention. The purpose of this review is to present some of the research conducted within the SCANDAT collaboration. We hope more international collaboration may help improve our understanding of the important remaining questions about donor and recipient health. [ABSTRACT FROM AUTHOR]

Background: Both hepatitis B and C viruses were transmitted through blood transfusion before implementation of donor screening. The existence of additional, yet unknown transfusion transmittable agents causing liver disease could have important public health implications.Methods: Analyses were based on the Scandinavian Donations and Transfusions (SCANDAT2) database. Cox regression models were used to estimate the hazard ratio (HR) of developing chronic liver disease in recipients of blood from donors who later developed any chronic liver disease compared to recipients who received blood transfusion from healthy donors. We also studied whether the risk of liver disease was increased in patients who received units from 'high-risk' donors, defined as donors who had a higher than expected occurrence of liver disease amongst their previous recipients. All analyses were stratified before and after 1992 to account for the effect of screening for hepatitis C virus.Results: A total of 1 482 922 transfused patients were included in the analyses. Analyses showed evidence of transfusion transmission of liver diseases before, but not after the implementation of hepatitis C virus screening in 1992, with HRs for any liver disease of 1.38 [95% confidence interval (CI), 1.30-1.46] and 0.99 (95% CI, 0.91-1.07), before and after 1992, respectively. Similarly, blood components from 'high-risk' donors conferred increased risks before, but not after 1992.Conclusions: Our data provide no evidence for transfusion transmission of agents causing liver disease after the implementation of screening for hepatitis B and C, and suggest that if such transmission does occur, it is rare. [ABSTRACT FROM AUTHOR]

Background and Objectives An increasing number of investigations into different aspects of transfusion therapy are being conducted using data extracted from a wide range of electronic data sources. Results of such observational studies, however, have in some instances been conflicting, possibly as an effect of variable attention to methodological and statistical detail. In this review, we will introduce and discuss some recent examples of important methodological problems. Materials and Methods We reviewed the recent literature of observational studies of possible deleterious effects of aspects of transfusion therapy, including donor factors, donation factors and component factors. From this literature, we identified a number of potential methodological problems and assessed these using data from the Scandinavian donations and transfusions ( SCANDAT2) database. Results The main finding of our review relates to the importance of maintaining sufficient attention to epidemiological and statistical methods. The most important factor to consider is perhaps the number of transfusions which is often found to be an important confounding factor in this field. We also review recently applied methods for studying disease transmission through blood transfusion. Conclusion While observational research in the transfusion medicine field has great potential for improving transfusion safety, pitfalls are plentiful and easy to overlook. In this review, we have gone over some methodological issues that we feel are especially important to consider for researchers who are involved in this type of research. [ABSTRACT FROM AUTHOR]

Background Risk of basal cell carcinoma ( BCC) has been reported to be several-fold increased among organ transplant recipients ( OTRs). However, due to lack of reliable BCC registration, population-based risk estimates are scarce. Objectives To characterize risk of BCC among OTRs compared with the general population, and contrast with risk of cutaneous squamous cell carcinoma ( SCC). Subjects and methods OTRs transplanted during 2004-2011 were identified through national healthcare registers and linked with the nationwide Swedish BCC Register initialized in 2004. Relative risk of BCC was expressed as standardized incidence ratios ( SIR) with 95% confidence intervals ( CI). Results Altogether, 4023 transplanted patients developed 341 BCCs during follow-up. Compared with the general population, the relative risk of BCC was increased sixfold ( SIR 6·1, 95% CI 5·4-6·9). The risk was higher in kidney and heart/lung than in liver recipients ( SIRkidney 7·2, 6·3-8·3; SIRheart/lung 5·8, 4·0-8·2; SIRliver 2·6, 1·7-4·0), and risk increased with time since transplantation ( Ptrend < 0·01). The SCC to BCC ratio was 1 : 1·7 and BCC developed earlier after transplantation than SCC. Distribution of anatomical sites and histological types did not differ substantially between OTR- and population- BCCs. Conclusions Risk of BCC was strikingly elevated in OTRs compared with the general population. Risk was higher in kidney recipients and increased with follow-up time. These findings support a tumour-promoting effect of immunosuppressive drugs in BCC development. The low SCC to BCC ratio was possibly attributed to short follow-up time. [ABSTRACT FROM AUTHOR]

Background and Objectives The consequences of ABO-compatible non-identical plasma for patient outcome have not been studied in randomized clinical trials or large cohort studies and use varies widely in the absence of evidence-based policies. We investigated if transfusion with compatible instead of identical plasma confers any short-term survival disadvantage on the recipients. Materials and Methods The cohort of all 86 082 Swedish patients who received their first plasma transfusion between 1990 and 2002 was followed for 14 days and the risk of death in patients exposed to compatible non-identical plasma compared to recipients of only identical plasma. Results After adjustment for potential confounding factors, there was an increased mortality associated with exposure to ABO-compatible non-identical plasma, with the excess risk mostly confined to those receiving 5 or more units (relative risk, 1·15; 95% confidence interval, 1·02–1·29). Stratification by blood group indicated higher risks in group O recipients, especially when the compatible plasma was from a group AB donor. Conclusions This study suggests that ABO-compatible non-identical plasma is less safe than identical plasma. Subanalyses by blood group suggest a role for circulating immune complexes. Our findings may have policy implications for improving transfusion safety. [ABSTRACT FROM AUTHOR]

Background and Objectives Even with appropriate donor deferrals and advanced screening tests, the risk of disease transmission through blood transfusion cannot be completely disregarded. Efficient monitoring of possible disease transmission between blood donors and recipients should be an important component of a comprehensive haemovigilance system. Materials and Methods We assembled the Scandinavian Donations and Transfusions (SCANDAT) database, with data on virtually all blood donors and recipients who have been registered at least once in any of the computerized local blood bank databases in Sweden and Denmark since the start of computerized registration in 1966. The records of these individuals, with their entire computerized donation and/or transfusion histories and all donor-component-recipient connections, were linked to nationwide population and health registers to attain essentially complete follow-up for up to 36 years regarding reproduction, hospital morbidity, cancer, and death. Results After data cleaning, the database contained 1 134 290 blood donors who contributed 15 091 280 records of donations and 1 311 079 recipients who received 11 693 844 transfusions. The data quality in the existing data sources was satisfactory. From the data obtained from local blood banks, 4·6%, 1·6%, and 6·4% of the person, donation, and transfusion records, respectively, had to be discarded after review of the legitimacy of recorded values, and comparisons with independent, external databases. Conclusion It is possible to use existing computerized data, collected in routine health care, in haemovigilance systems for monitoring long-term outcome and disease concordance in blood donors and transfusion recipients. [ABSTRACT FROM AUTHOR]