Diagnosis and procedure-specific survival among transfusion of recipients in 1993 and 2000, Orebro County, Sweden

The cost-effectiveness of introducing nucleic acid testing to test for hepatitis B, hepatitis C, and human immunodeficiency virus among blood donors in Sweden

BACKGROUND

The purpose of this study was to estimate the cost-effectiveness of using individual-donor nucleic acid testing (ID-NAT) in addition to serologic tests compared with the sole use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) among blood donors in Sweden.

STUDY DESIGN AND METHODS

The two strategies analyzed were serologic tests and ID-NAT plus serologic tests. A health-economic model was used to estimate the lifetime costs and effects. The effects were measured as infections avoided and quality-adjusted life-years (QALYs) gained. A societal perspective was used.

RESULTS

The largest number of viral transmissions occurred with serologic testing only. However, the risks for viral transmissions were very low with both strategies. The total cost was mainly influenced by the cost of the test carried out. The cost of using ID-NAT plus serologic tests compared to serologic tests alone was estimated at Swedish Krona (SEK) 101 million (USD 12.7 million) per avoided viral transmission. The cost per QALY gained was SEK 22 million (USD 2.7 million).

CONCLUSION

Using ID-NAT for testing against HBV, HCV, and HIV among blood donors leads to cost-effectiveness ratios that are far beyond what is usually considered cost-effective. The main reason for this is that with current methods, the risks for virus transmission are very low in Sweden.

Survival after blood transfusion

BACKGROUND

Long-term survival of transfusion recipients has rarely been studied. This study examines short- and long-term mortality among transfusion recipients and reports these as absolute rates and rates relative to the general population.

STUDY DESIGN AND METHODS

Population-based cohort study of transfusion recipients in Denmark and Sweden followed for up to 20 years after their first blood transfusion. Main outcome measure was all-cause mortality.

RESULTS

A total of 1,118,261 transfusion recipients were identified, of whom 62.0 percent were aged 65 years or older at the time of their first registered transfusion. Three months after the first transfusion, 84.3 percent of recipients were alive. One-, 5-, and 20-year posttransfusion survival was 73.7, 53.4, and 27.0 percent, respectively. Survival was slightly poorer in men than in women, decreased with increasing age, and was worst for recipients transfused at departments of internal medicine. The first 3 months after the first transfusion, the standardized mortality ratio (SMR) was 17.6 times higher in transfusion recipients than in the general population. One to 4 years after first transfusion, the SMR was 2.1 and even after 17 years the SMR remained significantly 1.3-fold increased.

CONCLUSION

The survival and relative mortality patterns among blood transfusion recipients were characterized with unprecedented detail and precision. Our results are relevant to assessments of the consequences of possible transfusion-transmitted disease as well as for cost-benefit estimation of new blood safety interventions.

False-reactive microbiologic screening test results in Swedish blood donors?how big is the problem? A survey among blood centers and deferred donors

BACKGROUND

Screening of blood donors for markers of transfusion-transmissible infectious agents leads to a varying number of false-reactive test results and sometimes thereby temporary or permanent deferral of donors and also to loss of collected units.

STUDY DESIGN AND METHODS

Data on false-reactive screening test results in 2002 and 2003 were collected from 19 blood centers in Sweden. A questionnaire was sent to donors deferred because of false-reactive screening test results to investigate their perception of the information and their reaction to the deferral.

RESULTS

Testing of 21,189 samples from new donors and 423,543 donations from regular and/or repeat donors produced 1,059 false-reactive test results, mostly from hepatitis C virus antibody testing, and 299 deferrals. Six different human immunodeficiency virus tests led to between 0.02 and 0.2 percent false-reactive results. The deferral rate varied considerably between different counties. Of 204 deferred donors contacted, 180 (88%) answered the questionnaire. More than 80 percent were worried about their test results and worry was more common among those who did not feel sufficiently informed.

CONCLUSION

The results imply that there is a need for a more standardized approach to the screening of blood donors and donations with the aim of minimizing the number of false-reactive screening test results. They also emphasize the importance of appropriate information and support to deferred donors.

Risks of fresh frozen plasma and platelets

Both fresh frozen plasma (FFP) and platelets are heavily used in massive transfusion. Although FFP can partially correct abnormal coagulation, a recent systematic review revealed no randomized trials showing clinical benefit. Although the overall risks of FFP and platelets are low, they are the least safe blood components, due to immunologic reactions such as allergy/anaphylaxis, transfusion-related acute lung injury (TRALI) and hemolysis due to anti-A or anti-B if transfused across ABO groups. TRALI, an acute syndrome of dyspnoea, hypoxia and pulmonary 'white-out' is now a major cause of transfusion-related death. Since it is usually triggered by donor HLA antibodies, selecting non- immune donors for FFP production may be beneficial. For platelet components, risks may be reduced by platelet additive solution, allowing removal of 70% of plasma. Platelets have the additional hazard of bacterial contamination, with donor skin the predominant source. Improved arm cleansing, divert pouches for the first 30-50 mL blood and bacterial screening have been adopted internationally. Virus risks are now vanishingly low, although new agents e.g. West Nile virus can still appear. Pathogen reduction for FFP is now well established in Europe, with solvent detergent and methylene blue methods licensed, and the psoralen amotosalen in trial. Loss of clotting factors and natural anti-coagulants are recognized side effects. Amotosalen is also licensed for platelet concentrates, with the added benefit of bacterial killing. In the UK, concern regarding vCJD has led to importation of US FFP for children.