Screening for human T cell leukaemia/lymphoma virus among blood donors in Sweden: cost effectiveness analysis

British Medical Journal, May 9, 1998 by Elsa Tynell, Soren Andersson, Eva Lithander, Malin Arneborn, Jonas Blomberg, Hans Bertil Hansson, Aud Krook, Mats Nomberg, Kristina Ramstedt, Agneta Shanwell, Anders Bjorkman

                                  Transfusion       Transfusion
              Year registered     recipients      recipients alive
Blood donor   as blood donor    identified (No)         (No)

1                  1985               19                 13
2                  1991               10                  5
3                  1966               21                  1
4                  1990                6                  3
5                  1993                5                  3
6([dagger])        1994                0                  0
7([double
  dagger])         1970               34                 16
Total                                 95                 41

                 Test result (No)

                                           Not
Blood donor         Positive   Negative   tested

1                       0          10        3
2                       1           2        2
3                       0           1        0
4                       1           2        0
5                       0           3        0
6([dagger])             0           0        NA
7([double dagger])      1          14        1
Total                   3          32        6

NA = not applicable.

(*) Only recipients younger than 65 and transfused after 1988 were traced.

([dagger]) Discovered to be positive at time of first donation.

([double dagger]) Discovered during pilot programme.

Cost effectiveness analysis

Three models were considered in the cost effectiveness analysis; they were assumed to have been implemented after all previously registered donors had been tested. The first model analysed the cost of continuously testing all donations; the second model analysed the cost of initially testing new blood donors and then retesting them after five years; and the third model analysed the cost of testing donors only at the time of their first donation.

The cost of testing every donation was 18 times higher than the cost of testing only new donors. The cost to prevent one transmission of the virus was 15 times higher when all donations were tested when compared to testing donors only at the time of their first donation. These estimates of the cost effectiveness of the three models are summarised in table 2.

Table 2 Estimated costs and benefits after the first year of three models of screening blood donors for human T cell leukaemia/lymphoma virus in Sweden. In the first model all donations were tested; in the second model only new donors were tested and then retested after 5 years; in the third model donors were only tested at the time of their first donation

                                              Model

                                       Every donation tested

Costs each year ($ million)                   3.02
Total costs ($ million) for:
 Each positive donor identified               1.90
 Each transmission prevented                  5.59
 Each case of disease prevented                222
 Each death prevented                          540
No of donors identified as
 positive each year(*)                        0.54
No of events prevented each year:
 Transmission of the virus([dagger])          1.59
 Cases of disease                            0.0136
 Deaths (incidence)                    0.0056 (1/180 years)

                                                Model

                                       New donors tested and then
                                         retested after 5 years

Costs each year ($ million)                      0.32
Total costs ($ million) for:
 Each positive donor identified                  0.22
 Each transmission prevented                     0.70
 Each case of disease prevented                   25
 Each death prevented                             63
No of donors identified as
 positive each year(*)                           0.46
No of events prevented each year:
 Transmission of the virus([dagger])             1.47
 Cases of disease                               0.0126
 Deaths (incidence)                      0.0051 (1/195 years)

                                               Model

                                       Only new donors tested

Costs each year ($ million)                     17
Total costs ($ million) for:
 Each positive donor identified                0.13
 Each transmission prevented                   0.44
 Each case of disease prevented                 15
 Each death prevented                           36
No of donors identified as
 positive each year(*)                         0.39
No of events prevented each year:
 Transmission of the virus([dagger])           1.35
 Cases of disease                              0.0116
 Deaths (incidence)                      0.0047(1/210 years)