Sunday, April 26, 2009

NFL draft 2009 thoughts, market inefficiencies

I am ecstatic about the Miami Dolphins picking up Pat White. I haven't been this excited about a pick since .... probably ever.

One thing I enjoy about sports is trying to determine where there are market inefficiencies. By that, I mean where the general consensus undervalues something. Examples of market inefficiencies:
1. Living in Pittsburgh. Pittsburgh has many of the attributes that make for a great quality of life, but is still relatively affordable.
2. Wines from South Africa. Considering the quality of the wines, you can get great values in wines from South Africa compared to other regions.
3. Great defensive players in the NBA. Offensive statistics are well defined in basketball, so it is easy for teams to probably determine the market values for player's offensive abilities. However, teams still struggle to quantify a player's defensive abilities, and therefore an NBA team can pick up a great defensive player (especially if their defensive skills are in something other than blocks or steals, which are readily measured) relatively cheap.
4. Short MLB pitchers. Major league baseball teams over-value height when rating pitchers. Therefore, you can pick up short pitchers at a relatively low cost.

For the entirety of my football-watching lifetime, there is one type of player that has been disproportionately successful at the college level, but not used well in the NFL- the option quarterback. Nearly every year, there are several star college quarterbacks who are able to tear apart college defenses because they can both run and throw effectively. However, because they don't fit the NFL prototype of the dropback QB, they either fail when asked to play NFL-style QB (which is essentially a different position), or are converted to another position (for some reason, safety is a common choice, but also WR or running back).

For the most part, these players are then perceived as failures. Eric Crouch, a Heisman trophy winner from Nebraska, was converted to safety and never did much. This is seen on some level as proof that option QBs can't succeed on the NFL level. The one guy who has been successful, Donovan McNabb, is not really the same player he was in college. In my opinion, Donovan McNabb was a far better college player. The NFL has literally cut off McNabb's legs- he was (until Pat White broke his record this year) the most prolific running QB ever. The fact that McNabb has been a decent (but, in my opinion, not great) thrower obfuscates what a great player McNabb could have been if he had been allowed to play his game.

So, what we've had over the past 20-30 years is a bunch of incredibly successful college QBs who are readily available in the late rounds of the NFL draft- guys like Brad Smith from Missouri, Major Harris from West Virginia, Joe Hamilton from Georgia Tech, Michael Bishop from Kansas State, etc. Every year, there is this one single group of terrific college players who are completely dismissed by the NFL, and because they can't change positions, are essentially told they can't play football.

It occured to me about 20 years ago that if an NFL team committed to playing the option, they could pick up these players on the cheap and create a series of schemes that NFL defenses would not be ready for. The players come so cheap (many aren't even drafted) that could stockpile 5 of them on your roster. If one gets hurt, just put another one in. You could even play 4 or more of them at the same time- one at QB, 2 at running back, and 1 or more at wide receiver.

For years, the NFL dismissed this as crazy talk. The NFL would make claims that you couldn't do something like this- the NFL defensive players are too fast and too tall, and the QBs would get hurt too frequently.

However, one trend changed the perspectives of the NFL- the rise of the SEC.

A few years ago, Arkansas was in an unusual position- they weren't a particularly good team and were particularly weak at QB, but they had arguably the 2 best running backs in college football at the same time- Darren McFadden and Felix Jones. So they decided to play both of them at the same time in a variation of the single wing offense, the Wild Hog offense. It was incredibly effective, and made McFadden into an even bigger star.

The next progression was the emergence of Tim Tebow at Florida. He was essentially a fullback during his freshman year when they won the national championship. He then became a full time QB, and the best in the country, winning the Heisman as a sophomore. But he still didn't fit the NFL prototype. But then, as a junior, he played the prototype NFL QB, Heisman trophy winner Sam Bradford from Oklahoma, in the national championship game. Bradford is a great player and will likely be the #1 pick in the draft next year and an All-Pro in the NFL, but even as a Bradford fan, I couldn't help but notice that Tebow was a better player.

NFL teams noticed too. Even 3 years ago, NFL teams would have dismissed Tebow as a pro QB prospect, but the confluence of trends has made teams realize that anyone as dominant as Tebow has been as a college player can probably dominate in the pros, if any team was ever willing to commit to letting Tebow be Tebow.

The third event (also involving an SEC player) was that the Miami Dolphins brought the Wildcat to the NFL. Miami was coming off an awful 1-15 season and lost their first 2 games, and early in the year was playing the mighty New England Patriots (who had went unbeaten the previous year) in the 3rd week of the season, at New England.

Miami killed them. They won 38-13, in what I think was one of the most shocking regular season games of my lifetime. What was more startling than just the score was how Miami won- they installed their running back Ronnie Brown in the Wildcat formation, and he had an absolutely monster game.

It's not an accident that this happened in Miami. Their QB coach, David Lee, had been the offensive coordinator and QB coach for Arkansas during the Darren McFadden years. He realized that the using a mobile QB in a varied offensive set could throw off NFL defenses designed to attack the classic dropback passer.

And now they have drafted Pat White, a QB perfect for the Wildcat formation. As a Miami Dolphins fan, I couldn't be more ecstatic.

Sunday, April 19, 2009

boggle, fossil digs, and patient care


I recently started playing a "Boggle" knock off on my IPhone. It's a frustratingly addictive game. When you first look at the 16 different letters on the 4x4 board, I usually only see a few words. Then, at some point I start getting a feel for the board, and start seeing a bunch of words that are within a letter of each other (sit, site, tie, ties, ....). Before I know it, 2 minutes are up, and I've still only seen perhaps 35 out of 130 possible words.

Playing it on a computer makes me realize how poor I am. When you play with friends, if I get 35 words, I feel like you've accomplished something, because I didn't realize that there were 130 words available for play.

It reminds me about what has been said about Michelangelo (or it may have been Leanardo da Vinci)- that when he looked at a block of marble, he could see the statue he was going to make, and all he had to do was chip away the marble that wasn't part of the statue. The point is that patterns are out there, and the limitation is in the human mind's ability to process what is right in front of them.

I most directly confronted this limitation in human observation 12 years ago, when I was in graduate school on a fossil dig. It was much less fun than it sounds, in no small part because I may be the world's worst fossil digger. We were looking for very small mammal fossils, with each bone being smaller than my thumbnail.

I remember one hot day, when I staring at a patch of dirt for over an hour. The patch wasn't particularly big- perhaps 3 feet by 3 feet, and I didn't see anything besides dirt and pebbles. Eventually, the expidition leader came by, and within 1 minute of looking at the same dirt I has spent an hour looking at, she was able to pull out three fossils. Through her more experienced eye, she was able to see things that my mind wasn't able to see. It was a striking (and humbling) example of how it takes practice to see patterns amongst the chaos.

This phenomenon comes up frequently as a physician. When I was first learning how to read MRI images, at first the images looked like a lot of noise to me. As I gained more iterations through practice, I started to filter out the noise, so at this point when I look at an MRI, I see lots of signal and very little noise.

This pattern repeated itself as I learned different techniques, whether it be performing nerve studies (electromyography and nerve conduction studies), spine injections, or using musculoskeletal ultrasound. It just takes practice.

It's a very similar way of developing the skills of playing Boggle. When you play Boggle, you eventually learn that it the word SITE is on the board, that you may also be able to spell TIE, and if you can spell TIE, you can probably also spell TIES, and SET, and SIT, etc. You learn which words commonly go together. So instead of seeing one word, you see 6 words.

Similarly, when you are looking at fossils, you learn that fossils will have rougher contours than pebbles, so you start to filter out the smooth contours.

Same thing with reading MRIs. You learn what a normal spine should look like on an MRI, and start filtering through if there is anything that looks abnormal.

One of my favorite cliches is that you need to listen for the dog that doesn't bark. I've actually never read any Sherlock Holmes novels, but my understanding is that he cracked a case because during a robbery, no one reported hearing the dog bark when someone broke into the house. This absence of a noise that should have been there indicated that the dog probably new the thief. It's a great example of knowing what should be present, and therefore being suspicious when the bark is absent.

I bring all of these tangential topics- Boggle, Fossils, Barking, etc- up in the context of patient care. I had a very interesting day of clinic on Friday. My patients had the normal mix of presenting symptoms- low back pain, knee pain, shoulder pain- but in fact my patients had an unusual mix of underlying problems that were far from straightforward.

I had a very good resident with me. After he had seen the patients, I asked him what I always ask the residents- "what do you think is going on, and what do you want to do?" We had one straightforward patient, but for all of the others, he wasn't sure what to do.

A common medical cliche is that we can all see the common diagnoses, but while we unusual diagnoses may see us, we may not see them. For example, I see hundreds of patients with herniated disks every year, but some of the patients who seem like they may have herniated disks may actually have cancer. One of the reasons patients see a fellowship trained specialist is for our ability to sniff out those odd cases.

It was interesting to watch the expression on my resident, as I could tell that he knew something was different with these patients, but he had not yet developed the experience to work through the differential diagnosis and determine what was actually going on. After I worked through the examination and discussed things with the patient, it became obvious. I am guessing, thought, that the experience was similar to playing Boggle when a competitor sees a word that was right there under our noses, or my experience when my expidition pulled out a fossil right from where I had already been looking.

And I guess that is what experience is all about- developing enough iterations to become a better observer.

Tuesday, April 14, 2009

Heterogeneity

One of the most common questions I get from patients is "will this procedure work?"

My answer is always some variation of "I don't know for sure, but ..."

Some procedures work very well, examples including:
1. Transforaminal epidural steroid injections for radicular pain ("sciatica") associated with a herniated disk.
2. Carpal tunnel release for carpal tunnel syndrome
3. Knee replacements for knee osteoarthritis

For many other procedures, however, there is far greater ambiguity. One of the main reasons for this ambiguity is heterogeneity.

Heterogeneity refers to the patient population not having much in common with one another, as opposed to homogeneity, which refers to all of the patients being similar. So, one of the reason's carpal tunnel surgery works well is that, for the most part, almost all of the patients who get the surgery truly have carpal tunnel syndrome.

That is not always the case, however. In fact, it is rarely the case. Patients are human beings, and human beings are unique, and this makes it difficult to assume that just because one treatment works for one patient, that it will also mean that the same treatment approach will work the same on another, different patient.

For example, in one of my favorite studies by Lurie and Weinstein et al from the journal Spine in 2006, they investigated the diagnoses associated with different surgical procedures. What they found was that for hip replacements, there was a high degree of homogeneity in terms of why the diagnoses for which the surgery was performed (i.e., most patients had hip replacements because of osteoarthritis), but that there was a far, far higher level of heterogeneity for when a lumbar fusion was performed.

The consequence of this heterogeneity is that the outcomes for hip replacements are far better than they are for lumbar fusions. For hip replacements, if the patient has a hip replacement, there is a very high likelihood it was done for a legitimate reason. For lumbar fusions there is a mix of some patients who were good candidates for the fusion and other patients who probably were not good candidates. As result, the outcome data for fusions is not particularly good. If patients were more narrowly selected, perhaps the outcomes would be better.

This same phenomenon- heterogeneity leading to less than optimal outcomes, comes up quite frequently. Other examples:

1. Spine injections. One of the main scopes of my practice is spine injections, including epidural injections, zgyapophysial joint injection, sacro-iliac joint injections, etc. The outcome data is not particularly good overall, although there are some subsets of patients for which the data is good (e.g., the aforementioned use of transforaminal epidurals for radicular pain, or SI joint injections).
The main issue is, again, heterogeneity. Spine injectionists, as a group, do a horrible in terms of applying standard of care. There is a great paper by Janna Friedly in 2008 that showed that only 42% of spine injections are performed with use of fluoroscopy. Only 42%! That is a bare minimum standard for an appropriate injection, and that is not factoring in whether the appropriate pain generator was selected, whether the proper level was selected, and whether the appropriate approach was used. This means that the absolute upper limit of how many spinal injections are performed appropriately is 42%, but when you factor in these other factors, it's likely that only 20-30% of spine injections are being performed according to standard of care. It's not shocking, then, that we are not seeing great outcome data.

2. Fibromyalgia. Fibromyalgia is largely a waste-basket term that encompasses a huge number of different diagnoses. In other words, there is a high level of heterogeneity. Just this morning, I was discussiong a fibromyalgia patient I see along with one of my rheumatology colleagues, and she is far from the typical fibromyalgia patient. A large number of fibromyalgia patients may have other diagnoses that have not been fully explored, including rhuematologic disease, depression, bipolar II disorder, myopathy, cervical myelopathy, Lyme disease, Epstein Barr Virus, etc.

Which brings me back to my conversation with patients. This is why, given the real world heterogeneity of patients, so often my answer to there questions is "I don't know for sure, but ...."