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The cost of allowing Men who have Sex with Men to donate blood
In a discussion on blood donation, it was said that excluding Men who have Sex with Men (MSM) from donating blood was not only discriminatory, but a waste of blood.
I said that the relative cost of allowing MSM to donate blood was high, and the relative benefit was low, and was countered with some atrocious calculations ("Out of the 3% gays, maybe 1 % have HIV. Meaning you eliminated 3% of 1% which is 0.03% comtanimated donations. This you call a high benefit ? 0.03% savings ? This is about 12 cents of €413.93. There must be hundreds of other ways to save the 12 cents.")
So, here is a calculation of the economics of banning MSM from donating blood (see below for the link to the Excel, which you can play around with).
(see below for justification of the assumptions, and a discussion of what happens when you change the variables)
In short, although the cost per clean packet of blood only rises from $801.40 to $802.65 if we allow MSM to donate, we know that economics teaches us that what is important is the marginal impact. And here, we see that the cost per additional packet of blood you get is $854.70, which is about a 7% premium. I confess that this is not as much as I expected, but coupled with safety reasons (see below) is provides additional reasons to keep the ban on MSM donating blood.
The calculation above assumes that the screening measures to keep the blood of infected non-MSM out of the system are ineffective (see: The Top 52 Reasons for Not Being Able to Donate Blood). To account for the measures, you can change the value of the "HIV infection rate in population" variable, since in the calculations it really represents the infection rate of the sample of blood donors, rather than the population as a whole, but this doesn't change the qualitative result, and the cost per additional packet from allowing MSM to donate blood doesn't change much anyway.
More importatly, this economic calculation does not take into account safety - there is a window period of 3-6 months during which HIV tests may give a false negative, i.e. saying that a person (or, in this case, blood sample) is clean although the person actually has HIV. This is a consideration because allowing men who have not had sex with men for a year to donate blood (we do the same for those who have visited prostitutes more than a year ago, or have had sex with a MSM more than a year ago) would not be acceptable to those who campaign for the ban on MSM blood donation to be lifted, since this would still discriminate against sexually active gay men (i.e. the vast majority of them).
Assumptions:
1) The cost per unit of blood donated is $800 (Kanavos, Yfantopoulos, Vandoros and Politis conservatively estimated that a unit of blood transfused cost between €294.83 and €413.93)
2) We have 10,000 blood donors (a priori assumption)
3) The sex ratio of blood donors is even (Different studies reported different things, but varying the sex ratio doesn't change the results for the cost of allowing MSM to donate blood, though it does affect the number of additional packets you will get. More importantly, I was lazy to change the ratio after doing my reporting)
4) 5% of males are MSM (this is a rough median of various figures I found; again, the relative cost does not change when this variable is changed, though the number of additional packets does)
5) The HIV infection rate in the population is 0.2% and 6.7% in the MSM population; the US population is 300 million, and the US Centers for Disease Control and Prevention's March 2010 newsletter reports that "MSM account for nearly half of the more than one million people living with HIV in the U.S. (48%, or an estimated 532,000 total persons)". Tweaking the variables gives similar results to the results reported earlier.
If you want to play with the variables (or check my formulae), you can download the Excel.
