Category: Medicine
Sentences to ponder
Cities that instituted quarantine, school closings, bans on public
gatherings and other such procedures early in the epidemic had peak
death rates 30 percent to 50 percent lower than those that did not.
That is from a study of the pandemic of 1918-1919 and here is more, from 2007. The best place to follow what is going on in Mexico — where such restrictions are now common — is ElUniversal. People in Mexico are dying of the flu every day; what is the chance that only the benign version of the virus crosses the border?
Are you hot?
Ever since the 2003 outbreak of SARS, or severe acute respiratory syndrome, Hong Kong has used infrared scanners to measure the facial temperatures of all arrivals at its airport and at its border crossings with mainland China.
From the comments, at Effect Measure
It surprises me that no one has mentioned this, so i'll end years of
quietly lurking and say it myself: a possible explanation for the
difference in clinical picture here vs Mexico lies in the sample size
here. 8 of 8 confirmed "swine flu" cases here have not involved serious
lower respiratory infection or death. But about 60 of about 1,000
generally unconfirmed cases of "swine flu" in Mexico have. If those all
confirm, that's about a 6% CFR. From what i've read, we don't have data
yet on the CFR of confirmed cases in Mexico, and we don't have a
satistically significant sample here for measuring phenomena in the
single percentage digits.
This tells me that there is no confirmed or statistically
significant difference in the clinical picture between US & Mexico.
Of course Mexico is where most of the data points lie. That's Suzanne Bunton. Read the other comments too. If the Obama administration believes in competent government, it would be nice if they would meet the public health standards currently practiced by the government in Mexico. Even a completed fence would not stop a virus and there is otherwise no reason to wait. Should we in the meantime count on a more favorable mutation to protect us?
The new swine flu: this is not a joke
The outbreak even hit Mexico's beloved national pastime — two sold-out
football matches Sunday — Pumas vs. Chivas and America vs. Tecos —
will be played in empty stadiums to prevent the spread of the disease.
Here is the story. Some people are puzzled as to how human, pig, and bird strains of the flu have mixed together, but if you have spent any time in rural Mexico the answer is obvious: these creatures all live together in close quarters.
Here is my earlier study on how an economist should think about avian flu and pandemics. You can follow the latest developments at Recombinomics and Crofsblog (the best blogroll on the topic) and Effect Measure. Revere, an experienced professional, puts it simply:
There is ample room for serious worry. WHO is convening its expert
panel under the International Health Regulations to determine if the
pandemic threat level should be increased from phase 3 to phase 4. In
our view, this isn't even a close call. We are in phase 4 and if WHO
doesn't call it they risk being considered irrelevant and without
credibility.
I will repeat the general point that public health is one of the best ways to spend government money, as it is (often, not always) a true public good.
Markets in everything, photographs only edition
Most folks never realize how cute microbes can be when expanded
1,000,000 times and then fashioned into cuddly plush. Until now, that
is. Keep one on your desktop to remind yourself that there is an
"invisible" universe out there filled with very small things that can
do incredible damage to much bigger things. Then go and wash your
hands. Lather, rinse, repeat.
Here is the web site. The options include human sperm, toxic mold, and, best of all, gangrene. If you read closely it seems you only get a picture, not the real thing.
I thank TheBrowser for the pointer.
The Addict
The author is Michael Stein and this is possibly the most interesting and engaging book I have read this year. The subtitle is “One Patient, One Doctor, One Year.” The ongoing dialogue between a doctor and his addicted patient defies excerpt but here is one small (non-dialogic) bit:
There is violence inside hospitals, and I am often surprised there isn’t more. In my experience it breaks out most often in the emergency room, the airport terminal of the hospital, the site of comings and goings, of transience, the stopover for travelers, the first landing for the already hurt. There is pain and fear, there is the anger and frustration that comes with bad luck’s arrival, compounded by the delays — for blood work and X-ray results — where it is clear that the staff is taking care of many people, where you aren’t the only one, just the one they are slowest to assist.
This book covers the notion of rational addiction, how and why people kick addiction, whether addicts are different in the first place, self-deception, the motivations of doctors, what doctors really do, how platonic yet romantic bonds develop, and many related issues. It is a memoir rather than formal science and it reads as well as masterful fiction, while being thought-provoking on many levels. Here is one very good review.
The bottom line: I just bought his other non-fiction book.
The War on Drugs: Methamphetamine
Remember when you could walk into a pharmacy and buy a decongestant like Sudafed? The key ingredient was pseudoephedrine, a precursor to methamphetamine. A series of laws made it more and more difficult to buy or manufacture pseudoephedrine (despite it's legality). So what did we get for our loss of liberty? A new paper (AEA) (free here) in the March AER says not much:
In mid-1995, a government effort to reduce the supply of methamphetamine precursors successfully disrupted the methamphetamine market and interrupted a trajectory of increasing usage. The price of methamphetamine tripled and purity declined from 90 percent to 20 percent. Simultaneously, amphetamine related hospital and treatment admissions dropped 50 percent and 35 percent, respectively. Methamphetamine use among arrestees declined 55 percent. Although felony methamphetamine arrests fell 50 percent, there is no evidence of substantial reductions in property or violent crime. The impact was largely temporary. The price returned to its original level within four months; purity, hospital admissions, treatment admissions, and arrests approached preintervention levels within eighteen months.
The authors conclude:
This is quite possibly the DEA’s greatest success in disrupting the supply of a
major illicit substance. The focus on disrupting the supply of inputs rather than of the drug itself proved extremely successful. This success was the result of a highly
concentrated input supply market and consequently may be difficult to replicate for drugs
with less centralized sources of supply, such as cocaine and heroin. That this massive
market disruption resulted in only a temporary reduction in adverse health events and
drug arrests and did not reduce property and violent crimes, is disappointing. (italics added)
FYI, this paper makes its case almost entirely by carefully laying out the data rather than with theory or econometrics–that was nice to see in the AER.
The Case Against Breast Feeding
Hanna Rosin's article on breastfeeding in the latest Atlantic is excellent and would make a topical and accessible introduction to causality studies in an econometrics or statistics class. (And lest that sound damning it's also a great read.)
The general point will be familiar to the audience at Marginal Revolution. The studies that show breastfeeding leads to lower weight, fewer ear infections, less allergies, less stomach illnesses and so forth are almost all observational studies.
An ideal study would randomly divide a group of mothers, tell one half to breast-feed and the other not to, and then measure the outcomes. But researchers cannot ethically tell mothers what to feed their babies. Instead they have to settle for “observational” studies. These simply look for differences in two populations, one breast-fed and one not. The problem is, breast-fed infants are typically brought up in very different families from those raised on the bottle. In the U.S., breast-feeding is on the rise–69 percent of mothers initiate the practice at the hospital, and 17 percent nurse exclusively for at least six months. But the numbers are much higher among women who are white, older, and educated; a woman who attended college, for instance, is roughly twice as likely to nurse for six months.
Moreover, the better we control for other factors that might account for differences in child outcomes between mothers who breastfeed and those who do not, the less evidence there is for breastfeeding's benefits. Even looking at children within the same family (still far from the gold standard of randomization), shows many fewer benefits from breastfeeding than studies that look across families. Some modest evidence suggests a gain in IQ and better evidence suggests minor improvements in avoiding some diarrhea. Rosin does not discount these benefits (so the title of her piece is unnecessarily sensationalistic) but she very appropriately does point to opportunity cost.
The debate about breast-feeding takes place without any reference to its actual context in women’s lives. Breast-feeding exclusively is not like taking a prenatal vitamin. It is a serious time commitment that pretty much guarantees that you will not work in any meaningful way. Let’s say a baby feeds seven times a day and then a couple more times at night. That’s nine times for about a half hour each, which adds up to more than half of a working day, every day, for at least six months. This is why, when people say that breast-feeding is “free,” I want to hit them with a two-by-four. It’s only free if a woman’s time is worth nothing.
One final point, Rosin's article is also usefully read as a study in propaganda and social psychology.
Upon waking up from a coma…
This time there were so many reader requests dear to my heart. Londenio asked:
Suppose you fall into a coma. You wake up in 15 years, with your memory
and cognitive abilities intact. You hug your loved ones, you brush your
teeth and then … what would be the first thing you would like to know
about the world?
Am I allowed three questions? They would be the level of stock prices (inflation-adjusted), whether there are new countries or old countries have disappeared, and whether nuclear weapons have been used.
And what about 300 years later, from having your head frozen?
I would simply ask: "What are the three most important questions I should be asking?"
What do you all think?
Sentences to ponder
Andrew Sullivan writes:
And that’s why black men in DC are more affected by HIV now than black men in Rwanda.
The (short-run) Obama health care plan?
Don't take this as definitive, but it's more than I've seen elsewhere:
Obama's budget request would create "running room for health reform,"
the official said, by reducing spending on some health programs so the
administration would have money to devote to initiatives to expand
coverage. The biggest target is bonus payments to insurance companies
that run managed-care programs under Medicare, known as Medicare
Advantage.
The Bush-era program has attracted nearly a quarter of Medicare
beneficiaries to private health insurance plans that cover a package of
services such as doctor visits, prescription drugs and eyeglasses. But
the government pays the plans 13 to 17 percent more than it pays for
traditional fee-for-service coverage, according to the Medicare Payment
Advisory Commission, which advises Congress on Medicare financing
issues.
Officials also are debating whether to permit people as young as 55
to purchase coverage through Medicare. That age group is particularly
vulnerable in today's weakened economy, as many have lost jobs or seen
insurance premiums rise rapidly. The cost would depend on whether
recipients received a discount or were required to pay the full price.
There's also a good deal of information about Obama's proposed budget in that article. On health care, here is Alex's earlier post on Medicare Advantage. Medicare at age 55 is an idea I don't hear much about; is the goal to lower the standard by ten years, every now and then, to move toward a single payer system? I would think that the 55 and overs would have an incentive, and the power, to block the extension of Medicare to everyone else and thus free-ride on a medical infrastructure financed by others. The Medicare extension also has to cost real money. If you believe in adverse selection, offering Medicare at any given premium will attract only the worst risks at that premium level. So what's the break-even point? Overall the real gains from spending more money are in public health programs for the relatively young.
Sentences to ponder
I'm not sure if the book is interesting, have any of you read it? But I remembered these sentences from a review:
as a mental patient who tells the intake counselor that she doesn’t
feel “safe” (the magic word) in the real world. (She tries to pay for
these visits herself, but fails: in one of the book’s few funny
moments, her insurance company rebuffs offers of cash, because only
crazy people bankroll such visits themselves.)
Here is more.
As an aside, I was sent this song about the financial crisis.
Sentence of the Day
From Alan Garber and Jonathan Skinner in, Is American Health Care Uniquely Inefficient (JEP or free here). Interesting throughout.
Cancer and Statistical Illusion
The cover of this month’s Wired promises "The Truth About Cancer" but the article inside is a tissue of misleading statistics and faulty logic. The article begins with fancy graphics telling us "If we find cancer early, 90 percent survive" but "If we find cancer late, 10 percent survive." And this:
Find the disease early "and the odds of survival approach 90 percent…This reality would seem to make a plain case for shifting resources toward patients with a 90 percent, rather than a 10 or 20 percent, chance of survival."
Thus, the opening block of text commands, "Scientists should stop trying to cure cancer and start focusing on finding it early. It’s the smart way to cheat death."
The fallacy in all of this is painfully easy to spot. If we measure survival, which these studies do, with a 5 or 10 year survival rate then obviously people whose cancers are detected early will survival longer than people whose cancers are detected late.
The key question is whether people who are treated early survive longer than people whose cancers are detected early but who are not treated. In Thomas Goetz’s long article there is not a single piece of evidence which demonstrates that this is true. Indeed, quite the opposite. About 9 pages into the article, after the jump, we find this about CT scans for lung cancer:
As with the Action Project, these studies found that, yes, CT scans detected a huge number of early cancers–10 times as many as they would expect to find without scanning. In that regard, the scans did their job as a screening test. And as expected, the number of surgeries based on those diagnoses jumped. But when Bach looked at the resulting mortality rates, he found essentially no difference between those who received a CT scan and those who had not. Despite the additional surgeries, just as many people were dying as before.
Nowhere does the author mentions that this finding invalidates just about everything he has told us in the first eight pages.
Addendum 1 : Do note that I have nothing against early detection and I am not claiming that it never works. My problem is with misleading statistical analysis.
Addendum 2: Careful readers will note that this is an almost perfect example of the economicitis fallacy that I blogged about late last year.
The marginal value of health care in Ghana: is it zero?
Megan McArdle points us to this scary report:
2,194 households containing 2,592 Ghanaian children under 5 y old were
randomised into a prepayment scheme allowing free primary care
including drugs, or to a control group whose families paid user fees
for health care (normal practice); 165 children whose families had
previously paid to enrol in the prepayment scheme formed an
observational arm. The primary outcome was moderate anaemia
(haemoglobin [Hb] < 8 g/dl); major secondary outcomes were health
care utilisation, severe anaemia, and mortality. At baseline the
randomised groups were similar. Introducing free primary health care
altered the health care seeking behaviour of households; those
randomised to the intervention arm used formal health care more and
nonformal care less than the control group. Introducing free primary
health care did not lead to any measurable difference in any health
outcome. The primary outcome of moderate anaemia was detected in 37
(3.1%) children in the control and 36 children (3.2%) in the
intervention arm (adjusted odds ratio 1.05, 95% confidence interval
0.66-1.67). There were four deaths in the control and five in the
intervention group. Mean Hb concentration, severe anaemia, parasite
prevalence, and anthropometric measurements were similar in each group.
Families who previously self-enrolled in the prepayment scheme were
significantly less poor, had better health measures, and used services
more frequently than those in the randomised group.