Tax Bullets

Gun violence is an enormous public health issue.  The CDC reports that 37,000 Americans a year are dieing from gun violence and another 71,000 a year are being injured.  That is over 100,000 gun shot victims a year.  About 10 billion rounds of ammunition are sold in the US every year, and cases of 1,000 rounds are readily available on line.  Do the arithmetic, there is about a 1 in 100 chance that at least one bullet in a 1,000 round case will end up being used to shoot a person.  That is pretty scary. 1 in 100 is not common, but it is not all that rare, about the same as the odds of drawing a pair of aces in blackjack.  But in blackjack, it is just a game of cards, with bullets we are talking about someone getting shot.

We need to focus on ammunition rather than guns.  We now have something like 350 million guns in the US.  These guns will last for decades.  Even if we halt all gun sales today, the US will still be awash with guns for generations to come.  As Senator Daniel Patrick Moynihan pointed out twenty years ago, there is much less ammunition in circulation, and ammunition, unlike a gun, does not last forever.  If we want to reduce gun violence in the near term, we need to focus on reducing the availability of ammunition.

We hear a lot about the need for freedom and personal responsibility these days. The people buying and selling ammunition need to take responsibility for the mayhem that they are causing.  The CDC estimates that firearm injuries and death cost the US  $37 billion dollars a year.  About 10 billions rounds of ammunition are sold every year in the US.   That works out to about $3.70 per bullet in deaths, medical care and lost wages.  Would $3.70 per bullet tax cause a big increase in the cost of ammunition?  Ammunition is currently available for less than $0.10 per round for many guns so yes, the tax would cause a big increase in the price of ammunition.  Would a tax on ammunition reduce gun violence.  We know that cigarette and alcohol taxes are highly effective measures at reducing consumption of these dangerous substances.  There is every reason to expect that a significant tax on ammunition would be similarly effective in reducing the injuries and deaths caused by ammunition.

We can also do much more to control who is buying ammunition.  Right now, ammunition is available at low cost, anonymously to anyone over the internet.  Ammunition is a very dangerous product.  It kills or injures 100,000 people a year in the US.  The Second Amendment stipulates the need for “a well regulated militia”.  Pretty much anyone seems to be able to get a hold of a gun, and having procured a gun, anyone can get ammunition in large quantities.  Clearly, we have failed in our responsibilities to maintain a well regulated environment within which our citizens can bear arms.  Along with a tax on ammunition, we need to much more tightly regulate who can buy ammunition, of what type and how much.  People buying ammunition must be required to provide proof that they carry liability insurance for its use.  Given the frighteningly high rate at which bullets are used to shoot people, it is amazing that we do not do this already.  All too often, shooting victims do not sue their shooters because there is no realistic possibility of recovering damages that would come close to compensating a family for a lost member or a seriously injured survivor for hospital bills and rehabilitation that will be required after the injury.  We require drivers to carry liability insurance because driving a car can cause injury to others.  We need to do the same for firearms.

We can control gun violence, and we can do it with measures that will be effective now, not a generations from now.  Putting a significant tax on ammunition, and requiring gun owners and ammunition buyers to demonstrate proof that they carry liability insurance would be a good place to start.

Of Big Food and Big Med

Writing in The New Yorker, Atul Gawande has an interesting article comparing management practices in a modern corporate restaurant chain, The Cheesecake Factory, to management in health care.  Gawande makes a number of interesting points about ways in which corporate management techniques have been applied to bring what was once an extremely diverse cottage industry of small restaurants of highly variable quality into a more reliable and efficient mode operation.  By comparison, much of health care remains in the cottage industry phase with few effective mechanisms in place to monitor and improve the overall efficiency and quality of the process.  The consequence for patients is often a confusing and poorly coordinated experience.

The Cheesecake Factory is clearly successful at delivering an experience that customers want, but the long term consequence for health do not appear to be a major part of the decision making.  On the positive side, TCF posts the nutrition data for their menu in an easily accessible format on line.  The bad news is that a decade after the film Supersize Me documented the adverse effects of excess caloric content of restaurant menus, the median caloric content of a meal at TCF is 2,000 calories (split an appetizer 340, main dish 1290, accompaniment 200 and beverage 160).  A single meal at TCF approaches the recommended daily caloric intake for a moderately active male (~2400) and exceeds the recommended daily caloric intake for women (~1800).  If you add a small salad (390 calories) and desert (930 calories), the median caloric content for a single meal at TCF goes up to 3,310 calories, well into the obesity inducing range for both men and women.

Making the analogy in health care, we might anticipate that modern corporate management would bring efficient scheduling, prompt service, pleasant waiting rooms, crisply dressed, cheerful attendants and more efficient billing.  The challenge will be insuring that the health of the patient factors prominently in the equation.

Of Pigs, Bugs, Drugs and Genomics: The Smoking Gun for Antibiotics on the Farm

This is a story that begins generations ago. Shortly after World War II, the makers of antibiotics realized that supplementing animal feed with antibiotic containing byproducts increased agricultural productivity.  Antibiotics were the miracle drugs of WW II, and at the time this seemed like yet another benefit.  However, by the 1970s, the emergence of resistant bacteria was becoming an increasing problem in medicine.  In seminal work, Levy showed that the introduction of antibiotic supplemented feed on a poultry farm led rapidly to changes in the gut bacteria of both the chickens and the workers on the farm, and to the emergence of bacterial strains resistant to the antibiotic in the feed.  Their article concludes:

“The present findings clearly demonstrate, however, that antibiotic-supplemented feed is a factor contributing to the selection of human resistant strains of bacteria. These data speak strongly against the unqualified and unlimited use of drug feeds in animal husbandry and speak for re-evaluation of this form of widespread treatment of animals.”

And that is how things sat for more than 40 years.  The agricultural industry argued that antibiotics were important in raising productivity, the drug companies sold literally tons of antibiotics in the agricultural market, shortly after each new generation of antibiotic was introduced in human medicine, they were distributed to the agricultural market, and shortly after that resistant strains emerged requiring the development of ever more potent (and expensive) new antibiotics.

If you think about it, feed supplements create nearly an ideal environment for the emergence of bacterial resistance.  The drugs are given at subtherapeutic doses to large populations of bacteria.  A few partially resistant variants gain selective advantage in this context, and as they proliferate and evolve greater resistance, they achieve even greater selective advantage until eventually they dominate the bacterial flora of the animals on the farm.

Unfortunately, farms are not research laboratories.  Workers are constantly and intimately exposed to waste products and aerosols as they care for animals, clean stalls and dispose of waste.  Thus it is not surprising that resistant strains could be passed from farm animals to human workers.  What is less obvious is that the farm animals might pick up bacteria from their human handlers.

Move the clock forward to 2012 and the era of modern genomics and inexpensive genome sequence analysis.  A multinational team showed that multiply resistant Staphylococcus aureus (MRSA; an important medical pathogen and public health threat) moved from humans to pigs, acquired additional antibiotic resistance, and moved back to humans.  They did this by sequencing the complete genomes of 88 bacterial isolates from multiple sources, a task that would have been unthinkable only a few years ago.  By sequencing the complete genomes, they were able to detect the minute genetic variations that all organisms acquire randomly from generation to generation (single nucleotide polymorphisms or SNPs).  By comparing the patterns of SNPs, they could determine which isolates were derived from which parental populations thus tracing the history of MRSA infection in pigs and its reintroduction in an even more resistant form back to humans.  This is the smoking gun that closes the loop and shows that not only does antibiotic use on the farm lead to resistant strains, but that it can directly lead to increased resistance in important human pathogens.

Finally, after 45 years, the FDA has issued rules beginning to govern antibiotic use on the farm.  Of course, MRSA did not exist back in 1974 when Levy et al. published their paper, and we now spend scarce resources tracking MRSA in the hospital and community.  And we are losing patients to untreatable infections.

The Case for a Calorie Tax

Americans, and increasingly peoples across the world, eat too much. We know we overeat. We complain about our fatness, we are constantly trying new diets and we blame the morbidly obese for their illnesses.  Over the past 20 years, we have done very little to change our eating habits.  In fact just the opposite, there has been an epidemic of obesity.

Perhaps it is time to take a lesson from other self-destructive habits like smoking and drinking. In both cases, the most effective method of control has been taxation. At $4/pack, most of the cost of a pack of cigarettes is the tax. By making cigarettes legally available but expensive, we have reduced both adult and childhood smoking and undoubtedly headed off many thousands of deaths due to cancer and emphysema.  Similarly, most of the cost of a bottle of liquor is tax, and the amount of alcohol we drink does depend on the price.

Alcohol consumption does increase cancer risk.  3.6% of all cancer cases and 3.5% of cancer deaths worldwide are attributable to consumption of alcohol.  Further, the risk of cancer increases with the amount of alcohol consumed.  Alcohol also increases blood pressure, risk for motor vehicle accidents and risk for work related injury.  By decreasing our alcohol consumption, alcoholic beverage taxes have prevented many thousands of cases of cancer, prevented hypertension and saved many lives.  As a public health program, the alcoholic beverage excise tax has been remarkably effective, and it even generates significant revenue.

What about food?  Excessive food consumption is clearly habit forming.  Ask anyone trying to lose weight.  The basic fact of obesity is that we are what we ate.  If a person is going to maintain an obese habitus (say 230 lbs for a 6′ tall male), they need to consume about 2740 calories.  This is about 300 calories more than than they would require to maintain an ideal body weight of 180 lbs.  If you reduce your caloric intake, you will lose weight.

How high would a tax have to be to make us alter our eating habits?  Let’s guess that making an unhealthy diet a few dollars a day more expensive than a healthy diet would be enough.  To use round numbers, a penny a calorie would make a 2740 cal obesity inducing diet about $3 per day more expensive than a healthy weight sustaining 2440 cal diet.  A 5′ 4″ female needs about 1800 calories to sustain an ideal body weight of 145 lbs and 2000 calories to maintain an obese weight of 175 lbs.  OK, so women get off a little easier.  On average the women would pay about $6 per day less than the men, about $2,000 over the course of a year.  This is still much less than the average wage disparity between men and women.  A little bit of justice in the world.   The same applies for height. Yes, tall people have a higher healthy body weight and need to consume more calories to sustain a healthy diet, but they also earn about $789 per year more for every additional inch of height, more than offsetting the increased calorie tax burden.  Growing children do need to eat more per body weight than do adults, but their overall caloric intake is still less than that of an adult.

How much revenue would a calorie tax generate?  The average American consumed about 2700 calories day in 2008 and the figure is increasing about 20 calories per year so we may now be closer to 2800 calories per day.  At a penny per calorie, the food consumption tax would be about $28 per day.   It would add $5.40 to the cost of a Big Mac, but only $2 to the cost of a chicken salad and only 31 cents to a serving of broccoli.  Multiplied by 311 million Americans and 365 days per year, the tax would generate about $3.2 trillion per year in revenue or about $10k per person per year at current rates of food consumption.  Yes, that would be a heavy and regressive tax, but it could easily be made less of a burden by reducing other taxes and issuing tax rebates that could be spent on either food or other items at the consumers choice.  Food stamps, could, of course be fully paid out of the food tax revenue.  On the other hand, a calorie tax would help to balance the federal deficit, and would help to cover the $179 billion per year in health care costs attributable to obesity.

Does a calorie tax have a chance of becoming law?  Well it does seem like a long shot given the prevailing anti-tax sentiment in DC today, and there are a number of well known politicians and pundits who might take it as a personal affront.   There are also large and politically active farming, food and restaurant industries that would undoubtedly oppose such a tax. Nevertheless, we have to start some place.  If Americans want to take meaningful steps to address the obesity epidemic, we should think seriously about the role of taxes.

The Broader Audience for Research Results

While libraries are an important component of research information dissemination, it is important to remember that there are many constituencies who lack access to libraries:

1)      Patients – in these days of cost containment and intrusion of insurers in care decisions, patients need to be, and are increasingly interested in being, their own advocates.  Most patients do not have ready access to a fully subscribed university library, but they need access to the literature to be effective advocates for their own care.  While many medical centers have patient resources centers that will provide a limited number of papers in hardcopy form, this is somewhat akin to the old days of inter-library loan and is not close to an effective substitute for direct electronic access to the relevant literature.

If we want community support for biomedical research, making the results of biomedical research accessible to patients is a critical step.

2)     Community health care providers – these physicians and nurse need to keep their own knowledgebase current and need to be effective advocates for their patients.  Again, most lack access to university libraries.  Yes, there are a large number of free “throw away journals” supported by advertising, but the editorial content of many of these journals reflects the sources of their advertising revenue.

If we want community health care providers to support biomedical research, making research results accessible is again a critical step.

3)     Small businesses and start-ups – while many start-ups may retain some personnel with some access to university libraries, this tends to be transient and unreliable.  Major pharmaceutical companies may be able to afford broad coverage subscriptions for their research staff, but this is not the case for most small to midsize businesses.  These small and midsize businesses are the real engines of economic growth and need to be considered in public policy.

This is getting repetitious, but business access to research results is an economic development issue as well as an issue for support of scientific research.

The current publication system, with expensive bundled subscriptions that only major research universities can afford, reinforces the ivory tower mentality on both sides.  Academics complain that business ignores them, but what do you expect if you publish in a journal not accessible to most businesses.  Conversely, businesses complain that academics are introspective and unconcerned about development and commercialization, but what do you expect when in many cases businesses are locked out of reading what is happening in academics.   The fact that universities are increasingly aggressive in pursuing intellectual property, and even suing their former faculty who have moved into commerce, does not help matters.

The old days when science in general and biomedical science in particular could depend on a few stalwart defenders in Congress are over.  Research funding is just another discretionary budget item in the eyes of many politicians.  Rebuilding ties with business and the community is critical to sustaining support for research funding, and the need for access to research results goes well beyond the academic community.

As has been pointed out, the high profit margin multinational publishers are struggling to find a sustainable business model in the era of electronic publishing.  I grew up in Rochester New York and Eastman Kodak was extremely generous to our community, but I am not going to argue that digital photography should have been suppressed until Kodak found a way to transition out of their film business.  The reality of modern business is that you innovate or die.  The publishers had a good run over the last 20 years, but if open access publishing is a better solution for the community, the publishers need to find their own future.

Why so many acronyms?

Biomedical informaticians are forever complaining that the language of medicine is inconsistent, imprecise, difficult to understand and potentially a source of medical errors.  Two particular complaints are the variety of ways in which a standard entity may be described and inconsistencies in the way a term or acronym may be interpreted.  Examples of inconsistent description abound.  For example, Ross Koppel has found 40 ways of recording blood pressure and 30 ways of recording tobacco use in an EHR.  A reasonable question is why doesn’t everyone agree on one standard way of referring to blood pressure and tobacco use?

Acronym collisions are a second source of irritation for the informatics community.  Acronym collisions occur when the same acronym is used for different purposes.   For example, PSA is used as a gene symbol for 7 different genes in the human genome.  Similarly, PCR may refer to polymerase chain reaction in molecular biology, phosphocreatine in metabolism, pathological complete remission in oncology and premature contraction in cardiology.  Given the theoretically enormous space of 3 and 4 letter acronyms, isn’t it surprising that different fields have settled on the same abbreviations for such different entities?   The space of pronounceable acronyms is far smaller than the space of all possible 2, 3 or 4 letter combinations, and the birthday paradox applies.  While there may be only a small chance in comparing the acronyms used in two different disciplines that they will choose the same acronym for two different purposes, as the number of acronyms in use in both fields increases, the probability that all the acronyms in one field will avoid all of the acronyms used in the other field becomes small.

Why not avoid the problem altogether and simply prohibit physicians from using acronyms in their medical notes?  To answer this questions we need to consider the forces driving language use in biomedicine.  Writing notes is a significant time burden for both physicians and nurses.  In a recent study, physician spent an average of 20 to 100 minutes per day writing (Hripcsak et al 2011).   Further, the time spent composing notes undoubtedly follows a Zipf-like distribution with a small number of clinicians writing a large fraction of all notes.  For the individuals writing most of the notes, the time spent on writing is substantial, and there is general agreement that clinical staff are under significant time pressure to complete a patient encounter as rapidly as possible.  The time spent documenting the visit counts just as much as time spent with the patient.  Shorthand and acronyms are valuable forms of data compression that reduce the amount of text that needs to be produced and as a consequence, greatly reduces the time spent writing.   This is not unique to biomedicine; natural language is highly compressed.  Pronouns are used all the time to refer to an expression occurring elsewhere in a corpus.  Replacing an entire noun phrase with a short simple pronoun is a great compression technique, but because any given pronoun could potentially refer to a number of noun phrases, there is often uncertainty in resolving the phrase to which a pronoun refers.  Probabilistic rules for anaphora resolution have been developed in the field of computational linguistics, but the process remains error prone, even for human readers.  If the informatics community truly wanted to reduce ambiguity in clinical text, an obvious first step would be to ban the use of pronouns.  This would, of course, incite a general revolt from the clinical staff, but the uncertainty associated with all of the variant nomenclature and acronym collisions pales by comparison the the ambiguity associated with the word “it”.

The most effective compression algorithm depends on the frequency of terms in a particular text stream.  Medicine is not a single homogeneous community.  Rather, there are dozens or hundreds of different communities, each with their own domains of expertise and relevant vocabulary and, of course, their own characteristic set of term frequencies.  In oncology, terms referring to cancer may be quite frequent while they will be less so in other fields of medicine.  The most effective compression algorithm for a clinical oncologist would, therefore, be a strategy the substituted short abbreviations for frequently used long terms, BC for breast cancer, DFS for disease free survival, OS for overall survival  or pCR for pathological complete remission.  In ophthalmology, RE and LE are not used for “right eye” and “left eye” because they conflict with common abbreviations.  Instead, ophthalmology has settled on OD and OS.  Nevertheless, determining the appropriate resolution of “OS” is straightforward in almost all situations.

Why are there so many ways to refer to a single entity?  The frequency of term use differs dramatically between disciplines.  A molecular biologist may use the polymerase chain reaction frequently and achieve significant text compression by abbreviating it PCR.  On the other hand, the molecular biologist might refer to breast cancer with only moderate frequency and therefore would avoid BC as potentially confusing but might still use BRCA.  Taking a population genetics perspective, acronyms can be viewed as alleles.  An allele (or acronym) will increase in frequency if it confers a selective advantage.  In the context of language, a selective advantage would be a large compression efficiency associated with relatively little ambiguity.  Each biomedical community has a distinct set of term frequencies so the optimal set of acronyms will differ between different communities (e.g. BRCA in molecular biology vs. BC in oncology).

Taking the analogy to population genetics a step further, ambiguity occurs at disciplinary boundaries.  When a clinical oncologist use pCR, they almost certainly are referring to pathological complete remission, but when a molecular oncology researcher uses PCR, it may be unclear whether they are referring to pathological remission or polymerase chain reaction.  The acronyms in use in one community are in effect competing with the acronyms in use in neighboring communities.  In population genetics, this is precisely the situation that results in selection for diversity and accelerated genetic drift.  A pathogen coat protein evolves to escape the host immune response.  The host immune response evolves to prevent growth of the pathogen, and both the pathogen coat protein and the host immune response genes end up evolving at a much faster rate than other genes.  As biomedical technology changes, the optimal set of acronyms for each community will drift to adapt to the changes in term frequency introduced by new techniques, and inevitably at the intersection of communities there will be acronym competition accelerating this drift.

Are acronyms a net source of error?  Certainly, it is possible that an acronym from one field might be misinterpreted by a reader from a different field, but compared to the pronoun resolution problem, this is a relatively trivial issue.   How often is OS in ophthalmology confused with OS in oncology?  Acronyms are highly context dependent, and almost always, the appropriate context in which to interpret an acronym is obvious.   Some informaticians have proposed rules forbidding the use of acronyms.  First, this is likely to greatly annoy users because it will force them to generate verbose, time consuming notes when their time would be better spent on other activities.  Second, it is likely to increase the overall error rate by increasing the length and complexity of the terms used in the text.

The use of acronyms may actually prevent errors.  Because acronyms are short, in their domain, common terms, the chance that the author will misspell the acronym is small.  The term for which the acronym substitutes is typically much longer and as a consequence invites a greater possibility of a spelling or typographic error.  How many ways are their to misspell multiple sclerosis or polymerase chain reaction compared to MS or PCR?  On balance, the use of acronyms is likely to reduce the overall error rate in biomedical communication.  Further, because acronyms compress the text and reduce the time needed to generate a sentence, the number of sentences a busy clinician is able to produce increases.  Would you rather that your clinical staff wrote a fixed number of sentences in a verbose acronymless style or more sentences in a condensed style facilitated by the use of acronyms?  From the perspective of the total information content of the note, the latter is clearly preferable, even if it results in occasional term collisions between disciplines.

Hripcsak G, Vawdry DK, Fred MR and Bostwick SB (2011) “Use of electronic clinical documentation: time spent and team interactions” JAMIA 18:112-117.

The Stability of Google

With algorithms drawing on billions of websites and petabytes of data, one might assume that Google’s search rankings are a relatively stable information resource.  An anecdote from today’s news suggests that caution is in order.  On January 6, 2012, a press release was issued http://www.cedars-sinai.edu/About-Us/News/News-Releases-2012/Moderate-Red-Wine-Drinking-May-Help-Cut-Womens-Breast-Cancer-Risk-Cedars-Sinai-Study-Shows.aspx that was picked up by a number of news organizations including UPI, CBS, Yahoo and news-medical.net.  The press release refers to a paper to appear in the Journal of Women’s Health (impact factor 1.5) that describes a small study (36 women) on the effect of red wine consumption on plasma estrogen and androgen levels.  The press release does not mention the numerous epidemiology studies showing no difference between red and white wine consumption; they both increase the risk of breast cancer even at modest levels of consumption (e.g. 1-5).

On January 7th, one day after the press release, a Google web search for “wine breast cancer risk” returned 8.3 million hits.  9 of the top 10 and 16 of the top 20 highest rank hits refer to the study described in the press release.  The 7th ranked hit is a web page from Calwineries.com that acknowledges an increased risk of breast cancer with heavy alcohol consumption but suggests that moderate wine consumption may be OK. The 13th and 17th ranked hits are earlier news stories reporting increased risk with alcohol consumption, and the 20th ranked hit is a Wikipedia page with a reasonable discussion of the increased risk of cancer associated with alcohol consumption.  Note that these are not the Google News ranks, these are the main Google web search results.

The PR firm employed by the research institute may be patting themselves on the back about their great success in promoting the visibility of their client, and the press release may have struck a nerve because many of us enjoy a glass of good wine and would really like to believe it will improve our health.   Unfortunately, many of the news articles have titles like “Red wine may reduce breast cancer risk” or “New Study Shows Red Wine May Reduce Cancer Risk In Women”.   A women seeing one of these news articles, might follow up with a Google search and conclude that a major study had been released causing a paradigm shift in the field and that consumption of moderate amounts of red wine would be protective against breast cancer risk.   The study in question is small, the article has not appeared in print, the journal in which it will appear has a modest impact factor, and the findings refer only to biochemical changes, not epidemiologically validated cancer risk.  There remains a substantial body of epidemiology showing that red wine consumption is associated with increased risk for breast cancer in human populations.  There is no paradigm shift.  It will be interesting to see how Google’s search results evolve over the coming weeks and months, but at present they are quite misleading.  Given the frequency with which physicians and nurses consult Google, the fickle nature of Google as an information source is worrisome.

Note: while this blog refers to Google searches, Bing.com and Yahoo.com also rank links to news articles about this press release highly in their search results.   Seems like everyone is losing sight of the need to provide reliable information in the race to be first with their search results.

1)      Willet et al. (1987) NEJM 316(19):1174
2)     Allen et al. J Natl Cancer Inst (2009) 101 (5): 296-305.
3)     Newcomb et al. Cancer Epid Biomarkers 18(3):1007-10.
4)     Li et al. European Journal of Cancer (2009) 45(5):843-50.
5)     Zhang et al. Am J Epidemiol (2009) 165 (6): 667–76

David J. States MD PhD FACMI
Chief Scientific Officer
OncProTech LLC

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