Archive | November 2013

New Heart Risk “Calculator” : Health care decisions from an Excel sheet?

I was just reading an article on the NYT which described a new method that doctors can use to decide whether to put patients on statins or not.

Statins work to prevent cardiac events by reducing cholesterol levels. While widely used, they are controversial as a means to prevent heart attacks in people without cardio-vascular disease.

As a public health guy, I’m interested in health diagnostics. So when I noticed that this hi-tech “calculator” was available for download from the NYT article, I immediately opened it up. I expected some sweet Java-based interface, with boxes to check a number of things like age, weight, ethnicity, dietary and exercise habits and family health history.

To my dismay, I found that it’s an Excel spreadsheet with space to enter ten items:

CVDCalc

As you can see, I filled in my own information (as best I could, based on recall).

I was happy to see that my lifetime risk of CVD is a mere 5% and, as I resist taking medications of any kind, even more happy to see that a doctor would likely not prescribe me statins.

However, I’m not sure what this really tell me. Does this say that I don’t have to exercise anymore? Can I eat tons of fried crap and finally ignore my family’s host of health problems now?

Mostly, I’m struck by how arbitrary this is. Smoking, high blood pressure, advanced age, being male and being African American are all known predictors of CVD. The absence of potentially modifying factors such as diet and exercise just make the picture even more arbitrary. I may be old, black and male, but I may have made lifestyle changes to counter those factors, thus reducing my risk for disease.

More frightening to me is how ad hoc medical care is. Doctors are praised for “shooting from the hip,” or making diagnoses based on gut feeling. In most cases, this is satisfactory. Sometimes health problems resolve themselves, or are too serious to effectively treat in the first place. Other times, this can lead to over prescription of medications or uninformed (praise god for the internet!) “patient directed medical care.” Though this calculator attempts to counter that behavior, I fear that its cheap simplicity makes a mockery of quantitative diagnoses of health risks, undermining the project’s goals.

The truth is, of course, that we really don’t know enough about complex diseases such as CVD. Though medicine is able to spot obvious candidates for serious disease (particularly after one develops it), the truth is that no one can say for certain whether, absent the obvious, one person is more likely to become ill than another. This calculator doesn’t change that.

It was a great epiphany for me when I realized that, though I am at low risk for CVD, given my expected long life expectancy, I am more likely to die due to, you guessed it, heart disease.

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Nairobi for a day (I think I will spend more time on a plane)

I’m back in Nairobi for a day. I think that I will have spent more time on airplanes that in Nairobi on this trip. It’s a pretty silly way to do business, but I wanted to be back home in time for Thanksgiving so I couldn’t extend it.

My friend Tirus picked me up from the airport. I mean, I pay him, but he’s still my friend. (Things are always quite gray in Africa.)

After the fire, the Kenyatta airport is still being run like patchwork, but it was the fastest that I’ve ever gotten through customs. Departures are routed through a giant tent. Arrivals have to go to a different part of the airport. It used to be that the two mixed, which created awful congestion throughout the airport. I think the fire actually did Kenya a favor. It’s still unclear when construction on the new terminal will begin.

It was interesting hearing Tirus recount his close call with the Westgate Mall attack. Apparently he was at Westgate relaxing and looking trough his phone not but an hour before the guns started to fire. Turns out it only took four guys to kill more than 70 people and wound nearly 200. Awful.

The ICC trials of the President and Vice President of Kenya are still news here. Actually, they are still news everywhere. Thinking about it, Kenya is in the American news on a daily basis. I think it might be the only African country that is.

I don’t know how the trials can proceed. Kenyatta’s and Ruto’s actions during the 2007 post-election violence were despicable, but it’s going to be rather difficult to successfully prosecute and sitting head of state, and maintain credibility for a struggling African country and a fledgling government. The ICC could actually cause more damage in the long term by pursuing the case, at least while Kenyatta is in power.

More later….. time for breakfast at the Seventh Day Adventist house. The claim to encourage “health living” by eschewing meat, spices and caffeine but the large amounts of salt in the food at this hotel are borderline dangerous!

Post 500!

judas-priest-freewheel-burning-1983I had planned some grand statistical analysis of this blog (such as that of post 100), but quickly found that 1) the text file version was too big to use and 2) stripping all of the complicated code from it is beyond my computer skillset.

So, I’ll celebrate simply by saying thanks to the four or five people who read this blog for, well, reading. Not much of what I say makes much sense, my politics are often vague and the themes are often haphazard and chaotic, but this remains an important tool for me. It’s not easy working through one’s thoughts and this give me a space to be incoherent, if not batshit nonsensical.

So thanks to all. It means a lot.

As, I’ve nothing else to say, here’s a run down of the top five posts:

1. African Conflict and the Murdock Map of Ethnic Boundaries At more than 15,000 views, this wins the top spot. It’s got pretty pictures and some suspect methodologies.

2. US Bombings in Laos 1965-1973 I thought this was a cool post. I went on a bender for spatial data on conflict for a while. It’s too bad I didn’t pursue it further. This one even came with a movie!

3. Andrew WK: How He Almost Became the US Cultural Ambassador to the Middle East No surprise here. It’s pretty easy to rack up hits on articles about rock stars. Global health… not so much.

4. Japan Earthquake/Tsunami Reporting April 7, 2011 I was downloading police reports of the number of dead and missing during the Tohoku earthquake/tsunami for a while. Then I went to Japan, didn’t have internet and couldn’t keep up with it. It was a valiant effort.

5. Lynching Data Are we starting to see a pattern here? I’m hoping that I haven’t put any misinformation out there with these odd data exercises. Unfortunately, my time is limited these days but it would be fun to get back into it. I was pretty wide-eyed and dreamy about data back then.

What I’m Reading Now

A couple of weeks ago, I was mulling over writing a book. Now that I’m fully disoriented from the ASTMH meetings and the submission of a giant NSF grant, I can’t really put my head together well enough to get it going.

So maybe I’ll briefly write about other peoples’ books instead.

As always, I’m reading several books at once. I’m usually horribly bad at finishing anything at all, and books are no exception. Right now, I’ve got the following on my desk:

cover-davis-quammen-spillover-book1. Spillover: Animal Infections and the Next Human Pandemic (David Quammen, 2012) – Many human diseases actually have their origins in animals. HIV moved from primates to humans. All human influenzas are diseases of animals. Awful infections like ebola and nipah virus are, in fact, bat diseases. However, the story isn’t as simple as humans simply becoming infected through contact with animals. Complex dynamics of inter-species transmission can create a situation where a pathogen turns from benign to deadly. The future of infectious threats requires that we understand these dynamics and prepare for them, particularly as mankind urbanizes and human movement intensifies. A great and easy to read work that doesn’t sacrifice details. Highly recommended.

2. Why Africa is Poor and What Africans Can Do About It (Greg Mills, 2010) – A truly sensible assessment of the roots of Africa’s economic and development problems. Instead of looking backward to colonialism and ambiguous global threats, Mills picks apart what’s wrong with modern African states and pulls no punches. The solutions presented, however, mostly rely on sacking most of the present leaders of African states, a tall order for some places. Even more odd, however, is the glaring absence of the structural adjustment era which attempted to free African states from crushing bureaucracy by dismantling typical state provisions like health care and schools. A great read, though.

3. The Great Escape: Health, Wealth and the Origins of Inequality (Angus Deaton, 2013) Though the 20th century saw incredible advances in living conditions, sanitation and medical technologies which have extended and improved the quality of human life, the benefits have not been uniform. Deaton offers that inequality is not a given, but rather a consequence of progress. It is the case that health disparities between social groups are highly correlated with economic inequality. Health disparities, a consequence of systems which encourage political and social inequality, in turn exacerbate the gaps between the haves and the have-nots. Another great and easy read.

exodus4. Exodus: How Migration is Changing Our World (Paul Collier, 2013) Economist Paul Collier takes on modern human migration, the extent of which the world has never seen before. He explores the political problems behind migration, the process by which people move from migrants to immigrants to citizens and the political implications of newly pluralistic states and an economically integrated world.

5. Asian Industrialization and Africa: Studies in Policy and Alternative to Structural Adjustment (Edited by Howard Stein, 1995) – It’s pretty much what the title says. There are several chapters tracking Asia’s move from a disastrous formerly colonized, agrarian area and poverty stricken area of the world to a powerhouse of industrial development and a major success story. African countries, however, have failed to develop as quickly, some even regressing economically during the 80’s and 90’s. The specific policies that allowed Asia’s success are contrasted with Africa’s failures and recommendations are offered to foster pro-active development in Africa. Asian policies, which were often protectionist and required the active hand of government but worked well at their particular stage of development, were at odds with those recommended during the structural adjustment era which recommended full privatization and haphazard relaxation of government controls.

2013 Meeting of the American Society of Tropical Medicine and Hygiene

ASTMH-Logo_tagline-BW1 (1)I just returned from this year’s meeting of the American Society of Tropical Medicine and Hygiene (ASTMH). For us in the developing country health world, it’s the biggest meeting of the year.. yet surprisingly small. Once you go to a few, you quickly realize you know just about everyone there.

Unfortunately, because I was preoccupied with a crushing NSF deadline, I didn’t get to see many of the presentations. I did, however, get to see many of the great people I know and, despite the deadline pressures, managed to have a great time.

Some highlights (for the layman), though:

1. Nipah virus: This one’s a beast. With a 70% case fatality rate (7 out of 10 people who become infected die), contact with this bug will pretty much assure there’s no tomorrow. Fruit bats area known reservoir though they seem unaffected by the virus. They urinate on pigs who transmit it to humans.

Sometimes, the bats urinate in certain tree sap collection buckets. People drink it directly, fall ill and then transmit to their families and kill them, too.

Because of Nipah’s ubiquity in fruit bats, the ease of isolating and producing stocks of the pathogen and it’s potential for major public health damage, the CDC has listed the virus as a Class C bioterror agent. Wow.

2. Imported zoonotic pathogens: More than 200 transmissible pathogens have been known to be imported into the US via the illegal wildlife trade. Remember, that most living things are mini-ecologies of bacteria, virae and fungi (yes, you too). Those people with the exotic snakes they imported in their bag? They brought more than snakes.

3. Plasmodium vivax (one of the four species of malaria parasites) relapses occur, on average, 14 months later. I found it interesting that it wasn’t 12. My mental transmission model confirmed that a 14 month relapse cycle would be much more suited to sustaining the pathogen than a more predictable 4, 6 or 12 month cycle. I will have to confirm with real (not fantasy) math, though. As vivax is a cold weather malaria, it makes a huge difference. Mosquitoes aren’t nearly as active in the winter.

It turns out, though, that I’m wrong, or misread the presentation (See Update below).

4. Nets with holes might be just as effective as nets without holes. We can stop collecting all those old nets and setting them on fire, now.

5. No one can agree on what dose of Primaquine to use during mass drug administrations to eliminate malaria. It’s kind of important. People with a particular genetic deficiency react badly to the drug, i.e. their red blood cells explode and they sometimes die.

6. A vaccine for malaria is on the way. It’s like the “check’s in the mail” for several decades. You can’t fault anyone for trying. We need one badly.

7. The Burma Restaurant in Washington, DC is truly fantastic, particularly the green tea salad, which tastes nothing like one would expect.

Outside of that, it was great to see friends. I can’t wait to see them again.


Update:

A friend wrote me to correct me on the timing of a relapse of P. vivax (and I appreciate it). Actually, it turns out he wrote a paper on it:

Here: The Plasmodium vivax that was once prevalent in temperate climatic zones typically had an interval between primary infection and first relapse of 7-10 months, whereas in tropical areas P.vivax infections relapse frequently at intervals of 3-6 weeks. Defining the epidemiology of these two phenotypes from temporal patterns of illness in endemic areas is difficult or impossible, particularly if they overlap.”

Here: Tropical P. vivax relapses at three week intervals if rapidly eliminated anti-malarials are given for treatment, whereas in temperate regions and parts of the sub-tropics P. vivax infections are characterized either by a long incubation or a long-latency period between illness and relapse – in both cases approximating 8-10 months.

And Here: Median relapse times for malaria caused by Old World parasites (tropical, 4.5 weeks [95% CI 3.6–5.4]; temperate, 8.5 weeks [95% CI 6.8–10.3]) were shorter than those for malaria caused by New World parasites (tropical, 27.5 weeks [95% CI 21.6–33.5]; temperate, 34.0 weeks [95% CI 32.0–36.0]). In addition, in both hemispheres, median relapse times for infections caused by tropical strains were shorter than those for infections caused by corresponding temperate strains, although this difference was not significant in the New World (Figure 3). The 95th percentile relapse times for the strain categories follow: Old World tropical, 9.5 weeks (95% CI 5.4–13.5); New World tropical, 40.3 weeks (95% CI 34.4–46.3); Old World temperate, 30.9 weeks (95% CI 19.9–41.9); and New World temperate, 97.7 weeks (95% CI 97.6–97.8). The HRs from the survival models (adjusted for neurologic treatment) follow: Old World tropical, 39.6 (95% CI 9.2–171.0; p<0.001); New World tropical, 0.93 (95% CI 0.36–2.41; p = 0.89); Old World temperate, 3.1 (95% CI 2.2–4.6; p<0.001)—all relative to New World temperate (reference).

Economic Inequality in the US: It’s Policy, Stupid!

TaxRatesandShareI’m reading an interesting paper that just appeared in a special issue of the Journal of Economic Perspectives from the American Economic Association.

“The Top 1 Percent in International and Historical Perspective” from Alvaredo et al. tracks the share of income held by the top 1% of a number of countries and finds what we already knew. Since the 1980’s, the share of income held by the top 1% has been on the increase and is reaching levels not seen since before the Great Depression.

Though globalization, technology and a fundamental change in how the top earners make money (finance vs. investment in manufacturing) are often implicated and seen as merely an unfortunate side effect of development, Alvaredo argue that increasingly regressive taxation structures are the culprit.

Further, they argue that the end of unions and the determination of wages through collective bargaining have tipped the scales against bottom level wages earners, increasing the share of the pie taken by the very wealthy.

Top tax rates have moved in the opposite direction from top pre-tax income shares. The second factor is a richer view of the labor market, where we have contrasted the standard supply-side model with the alternative possibility that there may have been changes to bargaining power and greater individualization of pay. Tax cuts may have led managerial energies to be diverted to increasing their remuneration at the expense of enterprise growth and employment. The third factor is capital income. In Europe—but less so in the United States—private wealth (relative to national income) has followed a spectacular U-shaped path over time, and inherited wealth may be making a return, implying that inheritance and capital income taxation will become again central policy tools for curbing inequality.

Of course, it’s not like most of us didn’t know this already.

Whether or not a very wealthy class becoming wealthier relative to everyone else is good or bad for society is a topic up for debate. The trouble, however, is that mass inequality give a small sliver of the population greater political power, which they can use to influence policy, to realize a limited number of self interested goals.

But we knew that already…..

What the hell was I going to write about?

I can’t remember, but it was one of three things:

1. To complain about Dambisa Moyo’s 2009 book Dead Aid, which I finally got around to reading. Basically, she says that Africa should give up on Western backed “aid” (she makes no effort to distinguish between different types of aid, and the contexts under which it is given), and do three things: 1) Have the west give African countries 5 years to phase out “aid” 2) Let China build all of Africa’s infrastructure for them (rather than the West) 3) Borrow money from private capital markets (she used to work for Goldman Sachs).

Given it’s haphazard treatment of details, it’s a pretty comedic book, but she gets accolades from right wingers who hate giving money to poor people. If you merely replace “aid” with the word “food stamps,” you’ll end up with the basic message of the American Tea Party: any amount of free stuff creates a “culture of dependence.” I’m sure she’s more educated and articulate than her book would suggest, but it appears that she is less concerned with writing useful policy analysis, and more concerned with waving a wide brush so she can raise her status as a celebrity.

While I don’t agree with everything Bill Easterly writes, he gives the subject a much better treatment.

2) To write about realism and caricature in Breaking Bad, or at least to note that I never get to see TV shows until after they are cancelled.

3) To reflect on the conservatism of punk rock music. I was listening back to some 80’s hardcore and remembering how horribly conservative a lot of this was. They had more rules on behavior than the Taliban (an inappropriate joke, but you get the idea…). Exactly what were they rebelling against, and what were they offering? Even Reagan was less uptight. A lot of us came out of some really chaotic situations, it’s odd (or maybe expected) that we’d gravitate toward dogma. Still, this stuff is no fun at all!

4) To complain about my low salary and uncertain prospects to make more money. This would make a horribly uninteresting post, however.

For now, though, here’s a trailer from a new movie on Punk from Southern Africa.

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