QALY/$ for promoting zinc as a common cold intervention
Epistemic status: Fun speculation. I know nothing about public health, and grabbed numbers from the first source I could find for every step of the below. I link to the sources which informed my point estimates.
Here’s my calculation broken down into steps:
Health-related quality of life effect for one year of common cold −0.2
~1.5 million QALY burden per year when aggregated across the US population
This is the average of estimating from the above (1e6) with what I get (2e6) when deriving the US slice of the total DALY burden from global burden of disease data showing 3% global DALYs come from URI
There’s probably a direct estimate out there somewhere
50% probability the right zinc lozenges with proper dosing can prevent >90% of colds. This comes from here, here, and my personal experience of taking zinc lozenges ~10ish occasions.
15% best case adoption scenario, from taking a log-space mean of
Masks 5%
General compliance rate 10-90%
100,000 QALYs/year is my estimate for the expected value of taking some all-or-nothing action to promote zinc lozenges (without the possibility of cheaply confirming whether they work) which successfully changes public knowledge and medical advice to promote our best-guess protocol for taking zinc.
$35 million is my estimate for how much we should be willing to spend to remain competitive with Givewell’s roughly 1 QALY/$71. This assumes a 5 year effect duration. I have no idea how much such a thing would cost but I’d guess at most 1 OOM of value is being left on the table here, so I’m a bit less bullish on Zinc than I was before calculating.
EDIT: I calculated the cost of supplying the lozenges themselves. Going off these price per lozenge, this 5 year USA supply of lozenges costs ~35 million alone. Presumably this doesn’t need to hit the Givewell spending bar, but just US government spending on healthcare.
It feels like this is still a research problem needing larger scale trials. If the claims are true (i.e. the failures to achieve statistically significant results were due to not preparing and consuming lozenges in a particular way, rather than the successes being the anomalies) there are plenty of non-philanthropic entities (governments and employers and media as well as zinc supplement vendors) that would be incentivised to publicise more widely.
Lifeextension cites this https://pubmed.ncbi.nlm.nih.gov/24715076/ claiming “The results showed that when the proper dose of zinc is used within 24 hours of first symptoms, the duration of cold miseries is cut by about 50%” I’d be interested if you do a dig through the citation chain. The lifeextension page has a number of further links.
Looks like they plagiarized from this paper, which found:
Results: Thirteen placebo-controlled comparisons have examined the therapeutic effect of zinc lozenges on common cold episodes of natural origin. Five of the trials used a total daily zinc dose of less than 75 mg and uniformly found no effect. Three trials used zinc acetate in daily doses of over 75 mg, the pooled result indicating a 42% reduction in the duration of colds (95% CI: 35% to 48%). Five trials used zinc salts other than acetate in daily doses of over 75 mg, the pooled result indicating a 20% reduction in the duration of colds (95% CI: 12% to 28%).
what I get (2e6) when deriving the US slice of the total DALY burden from global burden of disease data showing 3% global DALYs come from URI
I’m seeing 0.25% globally and 0.31% for the US for URI in the GBD data, ~1 OOM lower (the direct figure for the US is 3.4e5, also ~1 OOM lower). What am I missing?
QALY/$ for promoting zinc as a common cold intervention
Epistemic status: Fun speculation. I know nothing about public health, and grabbed numbers from the first source I could find for every step of the below. I link to the sources which informed my point estimates.
Here’s my calculation broken down into steps:
Health-related quality of life effect for one year of common cold −0.2
Common cold prevalence in the USA 1.2/yr
Modally 7 days of symptoms having −0.2
~1.5 million QALY burden per year when aggregated across the US population
This is the average of estimating from the above (1e6) with what I get (2e6) when deriving the US slice of the total DALY burden from global burden of disease data showing 3% global DALYs come from URI
There’s probably a direct estimate out there somewhere
50% probability the right zinc lozenges with proper dosing can prevent >90% of colds. This comes from here, here, and my personal experience of taking zinc lozenges ~10ish occasions.
15% best case adoption scenario, from taking a log-space mean of
Masks 5%
General compliance rate 10-90%
100,000 QALYs/year is my estimate for the expected value of taking some all-or-nothing action to promote zinc lozenges (without the possibility of cheaply confirming whether they work) which successfully changes public knowledge and medical advice to promote our best-guess protocol for taking zinc.
$35 million is my estimate for how much we should be willing to spend to remain competitive with Givewell’s roughly 1 QALY/$71. This assumes a 5 year effect duration. I have no idea how much such a thing would cost but I’d guess at most 1 OOM of value is being left on the table here, so I’m a bit less bullish on Zinc than I was before calculating.
EDIT: I calculated the cost of supplying the lozenges themselves. Going off these price per lozenge, this 5 year USA supply of lozenges costs ~35 million alone. Presumably this doesn’t need to hit the Givewell spending bar, but just US government spending on healthcare.
It feels like this is still a research problem needing larger scale trials. If the claims are true (i.e. the failures to achieve statistically significant results were due to not preparing and consuming lozenges in a particular way, rather than the successes being the anomalies) there are plenty of non-philanthropic entities (governments and employers and media as well as zinc supplement vendors) that would be incentivised to publicise more widely.
Is there a meta-analysis studying the effect size of this intervention? These seem unrealistically high to me.
Lifeextension cites this https://pubmed.ncbi.nlm.nih.gov/24715076/ claiming “The results showed that when the proper dose of zinc is used within 24 hours of first symptoms, the duration of cold miseries is cut by about 50%” I’d be interested if you do a dig through the citation chain. The lifeextension page has a number of further links.
That citation is retracted?
Here’s the Cochrane withdrawal notice.
Looks like they plagiarized from this paper, which found:
Good catch, thanks.
I’m seeing 0.25% globally and 0.31% for the US for URI in the GBD data, ~1 OOM lower (the direct figure for the US is 3.4e5, also ~1 OOM lower). What am I missing?