Writing Thursday in the journal Science, an international team of economists says countries that prohibit material rewards for blood donors may want to rethink that position, based on recent research.
"For a long time, there has been a sort of aversion to any form of reward, or economic incentive, to stimulate blood donations, based on the idea that this might actually reduce motivation because this is not an altruistic act," said study co-author Nico Lacetera of the University of Toronto.
There's also been concern among the World Health Organization and many blood collection agencies that incentives could attract donors who might be more likely to carry transmissible diseases, which could find their way into the pooled blood supply, he said.
Policies that prohibit monetary incentives have been based primarily on population surveys in which respondents were asked if they would donate blood if offered a cash reward, and the majority nixed that idea.
But Lacetera said responses were based on a hypothetical premise — not on studies of actual potential donors offered an incentive.
"If you look at more recent field studies based on actual behaviour — observational studies or large field trials — then the story is quite different," he said.
"All of these studies based on actual behaviour ... show that incentives do seem to attract more donations with no impact on the type of donor."
Lacetera and two other economists from the U.S. and Australia looked at more recent research in the United States, Argentina, Italy and Switzerland.
They found that in Italy, for example, offering blood donors a paid vacation day from work led to a 40 per cent rise in annual donations. Tempting potential Swiss donors with a five-franc lottery ticket raised donations to 47 per cent from 42 per cent, while a $10 gift card offer increased U.S. donations to 20 per cent from 13 per cent.
"The reward is not conditional on an actual donation," he said. "It's conditional only on showing up to a blood drive or a blood donation centre.
"The idea here is these organizations want to minimize the risk that someone misrepresents their health status or their past behaviour in order to receive the reward.
"So if you get the reward anyway, regardless of whether you actually donate or not, then once you come to fill the health history form they ask you to fill out, then you don't have any incentive to not tell the truth."
Lacetera cautioned that the economists' findings should not be interpreted as promoting a straight cash-for-blood policy.
"Our main message is look at this evidence and then make your decisions after you have taken this evidence into consideration."
Dana Devine, vice-president of medical, scientific and research affairs for Canadian Blood Services (CBS), said many blood collection systems in developed countries that prohibit cash-for-blood payments are starting to consider non-monetary incentives.
"We do occasionally put up material items that are available to people who come to a clinic, and receiving those material items is not dependent on giving a donation," Devine said Thursday form Ottawa.
"It's the idea of seeing whether those kinds of T-shirt or coupon-type incentives actually draw people into the clinic so they can see what it's all about and have a first-hand experience and get engaged," she said, adding that those items are usually in the $10 range.
Some blood agencies try to entice potential donors with contests for bigger-ticket prizes — "probably right up to a car in the last few years," Devine said. People come into clinics to enter their names for a draw, but aren't required in return to offer up their arms to give blood.
"So it's a different kind of motivator perhaps and also a different audience," Devine said. "This is probably not particularly appealing to the people who are already committed blood donors because they're coming in for some reasons that are more related to pure altruism."
In Canada, less than four per cent of people eligible to give blood are regular donors. Put another way, about one in two Canadians could be donating blood, but only one in 60 actually does. However, Canadian donors give more frequently on average than donors elsewhere in the world.
A for-profit company, Canadian Plasma Resources, wants to open three clinics — two in Toronto and one in Hamilton — that would pay money for plasma extracted from a donor's blood. Plasma is a component of blood that contains many proteins and can be used to treat diseases.
Lacetera said such clinics could end up competing for donors with Canadian Blood Services, especially if the centres are near one another.
"So for example, if there are two locations where you can collect blood and one offers rewards and the other doesn't, then we see some movement from people who were used to donating in the location where there were no incentives to the location where there are incentives," he said.
"But also it's important to consider this substitution effect because you want to look at the total effect. No matter if a person donates at location A or B ... we have to make sure that the total is greater than before, rather than just moving from one site to the other."
Note to readers: This is a corrected story. A previous version incorrectly stated the car prize was offered by Canadian Blood Services.