Why don't we have better medical textbook descriptions of disease?

I have a problem with the way medicine describes diseases. It’s not a new problem - it’s bugged me since about my third year of medical school - 1985 that is. I don’t think things have changed much.

To describe my problem, I’ll invent a disease “Y”.  Y has 3 findings - flat feet, pimples, and bad breath. Each occurs in 1/3 of the people suffering from Y.

What’s the probability that someone has flat feet and pimples given that they have Y?

No, it’s not 1/9.

I never said these were independent findings, and I never said they persist. Y starts with flat feet, then is asymptomatic, then patients develop bad breath and pimples. Yvians never have both flat feet and pimples at the same time. The old multiplication rule only works for independent events.

Ok, so you saw this one coming. Obvious, isn’t it? Well, yes, but most textbooks describe diseases as though they were collections of independent events without correlation or sequence or evolution or treatment effects. They provide long lists of symptoms, some of which rarely or ever coexist, followed by lists of findings, tests and so on. They very rarely, almost never, describe the long term sequelae of common acute conditions. (Often that’s because nobody has researched the “natural history” of the disorder. So the section would have to read “we have no idea” most of the time. That would be a start though.)

At the end of reading a classic textbook disease description you might be able to pass your Board exam, but you really have very little idea what the disease looks like, much less how it’s experienced by the patient. Sure, you learn that stuff after 5-10 years of patient care — but, really, that’s nuts.

Another way to learn this is to experience disease first hand - especially if you’re a 50+ physician. My own (one time) 1-2 day episode of vertigo didn’t match the textbook description of acute labyrinthitis or benign positional vertigo — it had features of both. It also left me with a subtle and persistent degradation of my balance - that doesn’t show up in textbooks either. Every 50+ physician can probably tell a similar story - our textbook descriptions of disease are misleading, incomplete, and frustrating.

I don’t think it was always this way. I have a 1930 edition of William Osler’s ‘The Principles and Practice of Medicine’ on my desk, what that book called “symptoms” was more the course of a disease. I wonder if the 19th century editions were even more case based.

We could fix this, but I never see anyone talking about it. We’d have to first admit we had a problem.

The American Heart Associations "911" heart attack campaign is not evidence based

My friend Jim Levin died a couple of years ago; he had an MI running for a plane. Shortly after his death I visited the American Hearth Association's warning signs of a “heart attack”. I wasn’t impressed. What active 55yo doesn’t have chest discomfort 20 minutes into a killer CrossFit workout? Short of breath? Yeah, a bit.

So I made my own list, based on nothing but my native ignorance ...

• If these things occur together it's more likely to be heart disease. So shortness of breath AND "cold sweat" [2] AND jaw discomfort all together means more than one of them by itself.
• It's one thing to feel short of breath when you're a healthy person running a 5 mile race, another if you are short of breath doing stuff that is normally easy (like watching TV).
• If symptoms like "arm discomfort" and " nausea" come on with exercise and get better with rest -- that's ominous. (Exercise means the heart needs more oxygen, so it can expose an underlying problem.)
• If your parents died of heart disease in their 40s and your LDL cholesterol is 250 and you smoke and you're male ... Ok. You get the point. Most of us have some heart disease by age 50, but some people have a lot. Weird pains at rest may not mean too much in a low risk 30 yo woman but in a "high risk" person they might be bad news.

Today I again thought of the AHA’s non-specific warning sign list. I thought maybe things had improved, so I went looking for a publication that describes the predictive value, or even sensitivity and specificity, of the AHA’s heart attack classification criteria. After all, we communicate the AHA list to hundreds of millions of people. There’s gotta be some science behind it … right ...

I found two interesting references, one predating my 2013 blog post

• Sensitivity, Specificity, and Sex Differences in Symptoms Reported on the 13‐Item Acute Coronary Syndrome Checklist. 2014
• Signs and symptoms in diagnosing acute myocardial infarction and acute coronary syndrome: a diagnostic meta-analysis 2008

The 2014 study was limited to patients who were actually in the ED. The 2008 study was broader and concluded: "there were almost no included studies that investigated the diagnostic accuracy of combinations of signs and symptoms …it was not possible to define an important role for signs and symptoms in the diagnosis of acute myocardial infarction or acute coronary syndrome”.

Dear AHA — this is ridiculous. I suspect if everyone took your 911 signs seriously ERs would be overwhelmed with “rule out MI”. You need to come up with an evidence-based symptom list.

Perspective - 20 year family reunion probabilities

For at least two good reasons I’ve been doing a bit of planning. More on those reasons later, but first a digression to answer a relevant question.

What is the probability that, estrangement aside, our nuclear family will be able to do a reunion in 20 years? Let’s assume for simplicity’s sake, no major disruption of civilization and no major changes in US mortality rates by age. I’ll also exclude Kateva, who is healthy at age 10 but unlikely to break canine longevity records.

It’s not hard to do the rough calculations, unadjusted for gender, wealth, education or health, using a basic Life table. I'm looking for 

tPx: probability someone aged x will survive for t more years.

and the formula based on a Life Table is:

Lx+t/Lx where Lx is the number surviving to age x

Lx can be found in the US 2010 Life Table. (Excel version can be downloaded from: ftp://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/NVSR/63_07/Table01.xlsx)

For my family the relevant values are:

Which gives survival probabilities for 20 years beyond current age as:

Where Product All is the product of each more-or-less independent probability. That is only about 50%, which is not so great. On the other hand, in the event of the cosmic calamity of my demise, I won't have much skin in the game. So the interesting number is the probability that Emily and kids make it assuming I do, which is Product “Impt” (important). That’s 71%.

Which is a useful number for my planning purposes and that future post I promised.

PS. I can remember when 20 years felt like a long time. It’s not.

Apple TV's PBS station has great shows, but an awful user experience

Anthro prof John Hawks, one of my favorite bloggers, is hosting a sure-to-be-good PBS series called First Peoples. You can stream the (ugh) Flash (ugh) version … too bad it’s not on Apple TV….

Except … it is. It’s just bloody hard to find. The PBS Channel Search menu searches only “Videos”, not “Shows”. To find Shows you have to scroll around … and around … and around… the “Shows” screen. Good luck with that. Once you find a show you can add it to Favorites.

I don’t know if this is something PBS can fix or if it’s some sort of Apple malfunction, but … wow … needs a fix. At the least Search needs to include Shows.

Automating medical error: misadventures in medication reconciliation

I recently enjoyed a nasal surgery procedure. More on that in a later post, this one is about a medical error that followed the surgery. It’s a kind of error that fits my professional work in clinical computing (“medical informatics”).

The error, actually multiple errors, showed up in a part of my computer generated post-operative discharge summary labeled “CONTINUE taking these medications”. In the clinical computing industry this is the “medication reconciliation” or “medrec” section…

AHRQ Patient Safety Network - Medication Reconciliation

Patients often receive new medications or have changes made to their existing medications at times of transitions in care—upon hospital admission, transfer from one unit to another during hospitalization, or discharge from the hospital to home or another facility. Although most of these changes are intentional, unintended changes occur frequently for a variety of reasons. For example, hospital-based clinicians might not be able to easily access patients' complete pre-admission medication lists, or may be unaware of recent medication changes. As a result, the new medication regimen prescribed at the time of discharge may inadvertently omit needed medications, unnecessarily duplicate existing therapies, or contain incorrect dosages. These discrepancies place patients at risk for adverse drug events (ADEs), which have been shown to be one of the most common types of adverse events after hospital discharge. Medication reconciliation refers to the process of avoiding such inadvertent inconsistencies across transitions in care by reviewing the patient's complete medication regimen at the time of admission, transfer, and discharge and comparing it with the regimen being considered for the new setting of care.

Most of the electronic health record (EHR) industry more-or-less automated medrec in the 00s. Typically a physician (usually this is a physician task) reviews a list of “existing” (tricky term!) medications as well as “new” meds and, in theory, produces a reconciled list that  fits the patient’s current sate.

That’s the theory; in practice the “existing” medication list is often incorrect.  Additionally, it’s usually quite easy to, with a click or two, replicate the “existing” medication list without the tedious work of actually reviewing it.

Both errors, and more, showed up in the “continue” list I was given for:

• Afrin 2 sprays 2 times a day
• Flonase 50 mcg/actuation
• fluticasone 50mcg 1 spray into each nostril daily
• azelastine 137 mcg 2 sprays into each nostril two times a day.

Let’s count the errors:

• None of these meds are appropriate for my post-op fully obstructed nose. The Afrin and steroid sprays are theoretically harmful, but in practice none of them would go anywhere anyway. So that’s 3-4 errors depending on how one treats Flonase/fluticasone. These is most likely either physician inattention or a process error.
• Flonase and fluticasone are Brand and Unbranded names for the same medication. This is a software error or a data entry/design error (accepting free text meds rather than “coded" meds).
• The Afrin dose and frequency is incorrect, it would be dangerous to use it so often. This is likely a physician error. (I actually corrected this during an office visit, but my correction was evidently ignored.)
• The list omits QNasl. This almost certainly an error in compiling the “existing medication” list, but like all the others it shouldn’t have been on the list post-of. I’ll count this as an error anyway.

So in one medication reconciliation process we have 7 errors, 1 which is probably software (Flonase/fluticasone resolution) and 6 which are physician/process errors likely facilitated by poor software design.

In this case no harm was done. My wife and I are both physicians; we knew to ignore the errors. There might have been a small potential for harm with a non-expert patient, but in practice the nasal meds aren’t going to get far in a post-op obstructed nose. Obviously there’s potential for harm in different cases, which is why “medrec” has been a patient safety goal for the past … well … 25 years or so.

This isn’t a new problem — Emily and I both remember common medication reconciliation errors in the pen and paper era. I suspect, however, that quick-click list merges may make it faster and easier to make the same old mistakes.

It would be nice to think about what we could do differently…

Story of our times - What happened to screen door latches?

This is the only screen door latch design sold in our local hardware stores:

 

The t-shaped metal bar in the center has two prongs that join the indoor mechanism. One first mounts the outdoor handle mechanism, then joins the bar to the indoor mechanism  and attaches it to the door. The bar slides into the outdoor mechanism collar. There’s no stop or spring in the outdoor mechanism, the bar can easily slide in and out. Only the two metal prongs at the tip hold it to the indoor mechanism.

After about 6-8 weeks of use at our home those prongs come loose, the bar slides deeper into the outdoor handle, and it is no longer possible to open the door. 

It’s a bad design. There should be a better way to attach the bar to the indoor mechanism, or there should be a spring in the outside handle.

This is different from the quality issues that afflicted toasters in 2006; the mechanisms are well made. It’s just that they’re well made to a hopelessly bad design.

I wonder if, years ago, a Chinese manufacturer incorrectly copied an older design. But why did it become universal?

I’m half-heartedly looking for a different design, but the market is probably telling us that nobody has a wooden screen door in 2015. We need to replace the door with something that will lose less heat in the winter.

Weird, and somehow characteristic of our times.

Crime and the enterprise

What do Seagrams, YouTube, Uber, Elon Musk’s PayPal, 1930’s McKesson, Jobs Rip. Mix. Burn, and Las Vegas have in common?

Many very successful enterprises have a history of unethical or criminal behavior. Sometimes there are convictions, sometimes not. The history is usually buried, sometimes it’s romanticized. Occasionally, as with Enron, the crime ends the enterprise.

I think if one wrapped the average CEO with Wonder Woman’s Lasso of Truth they’d confess to lesser versions of the kinds of sins that put Bernard Madoff in jail.

We don’t pay enough attention to this.

Fixing the iPad: Family share and iBooks

It’s a geek consensus - the iPad is on its last legs. Mostly this is because it’s nuts to have both a single-user iPhone 6 and a single-user iPad. You gotta be both top 2% for assets and have time to burn. Everyone else will do with either an iPhone 6 or 6+ (or Android equivalents).

There are obvious future fixes. One is for Apple to sell an iPhoneMini, based on tech developed for the failing aWatch [1], and a complementary iPad. That complementary iPad would work standalone, but it would also seamlessly switch between iCloud/iPhone user profiles — so a family of four iPhones might start with one iPad but move up to three (see also). [2]

There’s something else that’s gotten lost though — and I want to call this out. eBook adoption has stalled. That includes eTexbook adoption — my daughter’s school backpack is still 25 lbs. The iPad has dramatically failed to delivery on reading device expectations.

That’s big — because reading is what the iPad does best. Chromebooks have clobbered iPads in the classroom because, without the reading advantage, Chromebooks win on cost, durability, ease of management, lack of theft appeal, and suitability to traditional educational models. Video? Easier to watch up close on a lighter phablet, or rest your arms and use an AppleTV.

So it’s not enough to fix the iPad’s standalone single-user device model. Apple has to make the iPad a first class reading device. Google owns the K12 market now, but there’s still an opening in the post-secondary textbook market. More importantly, there’s the global market for books and magazines.

For that market, Apple needs to rethink its DRM approach. Sure, keep FairPlay proprietary for video — but use something else for books. Something that’s owned by an independent standards body and licenses for free along with a cross-platform authoring tool. Or, more radically, start paying authors up front for non-exclusive book distribution and then publish without DRM.

Be creative Apple. The iPad is too good an idea to die quietly.

[1] There’s an emerging consensus that aWatch 1.0 has failed. I expected it to fail in the US, but we need to see what happens in China. There’s a lot of room for improvement beyond 1.0 though: "A waterproof $150 iOS 8 Nano-clip replacement in Sept 2015 will be interesting. Splitting the cellular phone into multiple components, for which iPad and Apple Watch are interaction elements will be interesting. Standalone Apple Watch 4 running on next-generation LTE will be interesting.”

[2] Apple’s FairPlay Family Sharing, iCloud enhancements, and iOS 8 handoff do point in this direction.

Reorganizations - did Petronius Arbiter really say that in AD 27? No.

John Halamka is unhappy with the direction of federal health computing initiatives. He’s not alone, just about everyone outside of Madison Wisconsin is unhappy. My prescription would differ from John’s, and maybe I’ll write about that one day, but that’s not what this post is about.

This post is about a quote he references:

As Petronius Arbiter said in 27 A.D., we have to avoid change purely for the sake of change as this creates frustration

“We trained hard—but it seemed that every time we were beginning to form up into teams we were reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing, and what a wonderful method it can be for creating the illusion of progress while actually producing confusion, inefficiency, and demoralization.”

On the one hand, this is perfect. I speak, of course, from experience. I’ve lived through reorg death spirals — when the reorg interval falls below 12 months the end is quite near.

On the other hand, it’s too perfect. It turns out we know very little about Gaius Petronius Arbiter except that he hung out with Nero. Even allowing for the slanderous and largely fictional descriptions of the Roman emperors, he was probably no pillar of virtue. This doesn’t really feel like something a Nero flunky would say.

Turns out, it’s a misattribution. The original was by Charlton Ogburn (1911–1998) in “Merrill’s Marauders: The truth about an incredible adventure” in the January 1957 issue of Harper’s Magazine …

We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganized. Presumably the plans for our employment were being changed. I was to learn later in life that, perhaps because we are so good at organizing, we tend as a nation to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency and demoralization."

Ogburn’s article isn’t freely available, but you can read about Merrill’s Marauders: "a United States Army long range penetration special operations jungle warfare unit, which fought in the South-East Asian theatre of World War II, or China-Burma-India Theater (CBI). The unit became famous for its deep-penetration missions behind Japanese lines, often engaging Japanese forces superior in number.” They had a blood and brutal story. I have no idea how that connects to Ogburn’s observation on reorgs. Anyone know?

Medical research is hard - two NYT articles on Losartan for Marfan syndrome.

In 2013 the NYT’s Gina Kolata was optimistic about using Losartan, an angiotensin II receptor blocker (ARB), to treat Marfan’s syndrome …

… He sought a way to block the function of T.G.F.-beta and found a widely used blood pressure drug, losartan, that did just that.

In the mice, the drug prevented features of the syndrome, including ballooning of the aorta. Instead of dying of aortic aneurysms by three months of age, the mice lived a normal life span of two years…

… The Specks enrolled Daniel, and suspect he got losartan. His mother said the family saw “wonderful changes — everything started to stabilize.” Daniel’s aorta had been “growing astronomically,” she said, and that growth slowed so much that he would not qualify if he tried to enter the trial today. He also developed better muscle tone and more body fat.

When his time in the trial ended, the Specks were told Daniel could take losartan or the older drug, whichever they preferred. Ms. Speck did not want to take any chances. They chose both…

The human trial wasn’t finished at the time of publication but everyone was optimistic.

A year later Ms. Kolata wrote a followup article…

Heart Drug, Losartan, Falls Short of Promise in a Study - NYTimes.com

The idea seemed compelling: A blood pressure drug was found to block the effects of a gene mutation that causes Marfan syndrome, a condition that leads to terrible heart problems. The drug worked in mice with a gene that causes Marfan, doing just what everyone hoped it would do. A pilot study with 17 children showed the drug seemed to work in them, too, although there was no group that, for comparison, did not get the drug.

Now the more objective human evidence is in — results from a large clinical trial testing the experimental drug against the standard treatment. There was no difference in outcomes…

The standard treatment is a beta blocker - atenolol. It’s thought both drugs work better than placebo, so losartan isn’t necessarily ineffective, it just doesn’t seem to work as well in humans as it does in genetically modified mice.

Medical research is hard.

PS. I found the 2013 Losartan ref in my Pinboard share stream, specifically, in an accidentally untagged portion the stream I was reviewing. Seeing it I wondered if there was a followup article….

 

Paul Theroux's 1976 visit to Santa Ana, El Salvador - repeat on 2015 Google Street View

Paul Theroux’s The Old Patagonian Express was published in 1979. Today it’s as much historical document as travel guide. Part of that history is experiencing the semi-conscious neocolonial attitudes of 1970s Theroux, though that’s probably his personality as much as the times.

There’s a lot he disdains, but he liked Santa Ana El Salvador. At one point he claims it wasn’t on his map; for him it was a pleasant surprise.

Today you can retrace his journey with very limited version of Google Street View. You can’t navigate in the usual Street View way, but you can visit the primary plaza and you can browse user contributed images.

I wonder how long it will be for Santa Ana to go full Street View. On the one hand it’s amazing what’s there now, but it’s noteworthy that Santa Ana is still a bit mysterious.

How to (properly) use a nasal spray

It’s spring in Minnesota, so a new allergy season. Many of us are restarting our nasal sprays - often Flonase, which just went ‘over-the-counter’. Many of us are also doing it wrong.

I know I have, and I know most physicians don’t describe proper use. Mostly because most physicians don’t know there’s a right and wrong way. I recently interrogated an allergist (they do know this stuff) and here’s what I learned:

• Don’t snort it. Breathe normally or don’t breath.
• Don’t jam the nozzle up the schnozzle (sorry). Just a few mm in.
• Aim away from the septum — there’s nothing there to spray, it runs out, and it can hurt the thin mucosa there. Aim towards eye on same side of nostril.
• If you cross-over, use right hand to spray left side and vice-versa, you get right position.
• Don’t mix sprays or mix with nasal irrigation. Volume effect — one spray solution washes out another. Recommendation is to space 1 hour apart. (Which is a pain. I wonder how real this is, but that’s the party line.)

Now you know. Go forth and sin no more.

A data lock free local file format for a concept map or mind map application

It occurred to me, probably not for the first time, that there’s a natural local file store data lock free ‘file format’ for a concept map or mind map application.

Treat each node as a file system directory (folder) and make the node name the name of the folder. Treat hierarchical relationships between nodes as container relationships in the file system. Represent other arcs as hard links (unix) or soft links/shortcuts/alias contained with a folder. (Would be good to be able to distinguish Aliases that represent relationships between nodes from Aliases to system files that are properties of the node, such as an nvAlt/Simplenote text file.)

Treat other contents of a folder as properties of the node, such as notes (plain text, RTF, etc). 

And so on.

That’s the file “format”, the UI can be any variant of current Mindmap/concept map. User interactions turn into file system calls.

I’m sure someone has done this somewhere. Anyone know of a reference?

Happy accident fraud - Feds move on Aetna and other health insurers with deceptive provider listings

Happy accident frauds are emergent frauds — nobody needs to plan them. Don’t put your Disability Claims office on the fifth floor of a building with a faulty elevator to defraud anyone, just do it for the cheap rent. Then save costs by replacing your customer support staff with an automated call management system.

The insurance industry is great at emergent frauds enabled by complexity and powered by perverse incentives. It’s baked into their business model; any player who doesn’t cheat will go bankrupt.

So it’s not surprising that health insurers competing in public marketplaces have produced inaccurate physician directories. It’s not limited to public ACA style coverage, we get our Minnesota health care through an employer plan, and after we chose Aetna we discovered their oral surgery listings were fictional. They seemed to have many providers available in our area, but all the ones we called said the listing was wrong.

Why pay the costs to maintain an accurate listing when an inaccurate listing gets you customers who can’t actually make claims?

The good news is that the Obama administration is now starting to address the problem. Alas, the fines are likely to be pathetically small, we’ll need class action litigation to really change things or find ways to drive the worst offenders out of business by failure of ‘network adequacy’. (emphases mine, note the related problem of prince concealment in the industry, another part of a fundamentally murky business)

White House Moves to Fix 2 Key Consumer Complaints About Health Care Law - NYTimes.com

The White House is moving to address two of the most common consumer complaints about the sale of health insurance under the Affordable Care Act: that doctor directories are inaccurate, and that patients are hit with unexpected bills for costs not covered by insurance.

Federal health officials said this week that they would require insurers to update and correct “provider directories” at least once a month, with financial penalties for insurers that failed to do so. In addition, they hope to provide an “out-of-pocket cost calculator” to estimate the total annual cost under a given health insurance plan. The calculator would take account of premiums, subsidies, co-payments, deductibles and other out-of-pocket costs, as well as a person’s age and medical needs.

Since insurers began selling coverage through public marketplaces 19 months ago, many consumers and doctors have complained that the physician directories are full of inaccuracies. “These directories are almost out of date as soon as they are printed,” said Kevin J. Counihan, the chief executive of the federal insurance marketplace.

Medicare and Medicaid officials have found similar problems in the directories of insurance companies that manage care for beneficiaries of those programs. In December, federal investigators said that more than a third of doctors listed as participating in Medicaid plans could not be found at the locations listed.

The new standards significantly strengthen an earlier rule, which required insurers to publish directories online and to make paper copies available on request. In the federal exchange, violations are subject to civil penalties of up to $100 a day [ed: 0.000001% of revenue?] for each person adversely affected.

Federal officials said that inaccurate provider directories could be a sign of larger problems. If doctors listed in a directory are not available or are not taking new patients, consumers may not have access to covered services, and the insurers may not meet federal standards for “network adequacy,” the officials said. Consumers must often pay extra when they use doctors outside the network of their health plan, so an inaccurate directory could also lead to higher costs for patients.

… Aetna says that data in its directory is “subject to change at any time.” UnitedHealth tells Medicare beneficiaries, “A doctor listed in the directory when you enroll in a plan may not be available when your benefits become effective.” …

See also:

• Emergence: how entropy and incentives create scams: 2009, Aetna’s FSA management - just make it hard to process a claim
• Mobile phone fraud - The accidental data charge and other scams: 11/2009. A lot of these scams have gone away during the Obama administration, thanks to more competition between carriers and a lot of regulatory action. Government can work.
• Emergence: how entropy and incentives create scams 2/2009.
• Emergent fraud: Anthem and automatic payment denials 9/2010
• Anthem - Putting the Hell in Health Insurance 8/2010
• Health insurance: we’re defeated by a complexity attack 11/2009
• Employment benefit complexity: we are sheep 11/2007
• The hidden insurance problem: they can play the game better than we can 11/2007

Alpha (the better twitter) on app.net 1 year post-death, is like this...

Alpha (the better twitter) on app.net, 1 year post-death, is like this (xkcd: Undocumented Feature  by Randall Munroe, used with permission):

I’ve read we have 1,200 active members now.

One day I’ll write a post about life in a highly transient technology environment and what this might mean. Maybe I’ll just quote Vernor Vinge.