Samstag, 20. Juni 2015

Optimizing resource use by outsourcing of lifespan research

Is it possible to outsource lifespan studies to laypeople (who are supported by professionals)? The idea may seem far-fetched to some of you, but in the end it would amount to a "pragmatic trial"; which is certainly an accepted study design. This type of study is generally less rigorous but considerably more realistic than a classic RCT (3).
It should be easy to get pet-owners to participate since life span testing on animals it at worst ethically neutral and most probably a net positive for the animals. Obviously, drugs and interventions designed to extend the lifespan will be minimally invasive and have a high risk/benefit ratio. Sine qua non. And since all animals age, enrolling them in such a trial would be beneficial for them; like enrolling cancer patients in a cancer trial.

Outsourcing of lifespan studies to pet owners
The idea seems ingenious and abstruse at the same time (1), but these days it has reached the mainstream. As we have discussed, Kaeberlein and others have suggested to test rapamycin for late-life rejuvenation in dogs. The advantage is obvious. As a researcher you can save on housing facilities, animal food, doctor visits and drugs (loving pet owners visit the veterinarian themselves), caretaker costs, taxes, toys, accessories, "environmental enrichment". On the other hand, you still have to pay drug costs, additional vet visits (e.g. specialized tests), recruitment, administrative costs and the salaries of the involved researchers. As it turns out, all the latter costs are quite high. Kaeberlein mentioned costs in the range of 10^5 to 10^6$for his study. Additionally, you have to cope with the added problem of heterogeneity (every pet owner behaves somewhat differently) and lack of training (these people are not trained technicians or health professionals).

Outsourcing of lifespan studies to zoos?
There are more than a thousand zoos world-wide by a conservative estimate (2), perhaps closer to 5000. I see no reason why those places could not conduct lifespan studies, if pet owners can. So far, I think I'm the first person to propose this study design. The idea is simple, one could for instance, mimic a cluster randomized trial (4). The advantages over individual pet-owners are lower heterogeneity in husbandry, availability of primates, better access to trained professionals, improved record-keeping, etc. It's difficult to think of a disadvantage, except that it's harder to recruit Zoos for altruistic reasons than pet-owners.
Edit: I briefly brought the idea up at an aging conference I attended and felt little optimism. I think the concern is that husbandry is worse in practice than one would assume and the aggressive use of euthanasia precludes an aging study. It seems no zoo wants to keep elderly animals that might look unhealthy (even if they are not suffering). This is an important concern, I agree, and it remains to be seen if my idea is feasible.

General ethics of animal keeping
There are concerns that keeping animals is unethical per se. (Some would even argue that all animal research is useless [5b]. They are wrong.) Husbandry is often criticized, especially in Zoos (5). I am sure this can be improved and it is necessary to do so. But is it unethical to keep well-husbanded animals? In the case of many animals the answer is, definitely not. The reason should be self-evident to any loving pet-owners and right now I don't want to delve into the details. Just to mention, an interesting argument for the ethics of keeping lab mice for longevity research is that they live longer, healthier and more peaceful lives in captivity than in the wild (6). At some point, I will probably do a longer post on research ethics in animal studies.

References
1. I became aware of this idea perhaps 5 years ago. It was championed (maybe even invented) by Edouard D. and other people from longecity/imminst.
http://www.longecity.org/

2. http://www.statisticbrain.com/zoo-statistics/

3. Patsopoulos, N. A. (2011). A pragmatic view on pragmatic trials. Dialogues in clinical neuroscience, 13(2), 217.

4. Donner, A., & Klar, N. (2004). Pitfalls of and controversies in cluster randomization trials. American Journal of Public Health, 94(3), 416-422.

5a. http://www.captiveanimals.org/news/2010/03/10-facts-about-zoos
5b. http://www.isthmus.com/archive/isthmus-35/june-4-2004-inside-the-monkey-house/
(not yet read in full)

6. Suckow, M.A., Stevens, K.A., Wilson, R.P., 2012. The Laboratory Rabbit, Guinea Pig, Hamster, and Other Rodents. Academic Press.
Note: The deer mouse (Peromysces), for instance, lives 8 years in captivity but only ~1 year in the wild.
I cannot find the data for M. musculus but it looks very similar from what I recall.

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