One of the successful insights to training neural networks has been the rectified linear unit, or short the ReLU, as a fast alternative to the traditional activation functions such as the sigmoid or the tanh. One of the major advantages of the simle ReLu is that it does not saturate at the upper end, thus the network is able to distinguish a poor answer from a really poor answer and correct accordingly.
In this tutorial I will benchmark a few different implementations of the ReLU and PReLU together with Theano. The benchmark test will be on the MNIST database, mostly for convenience. Continue reading →
I recently e-mailed Freakonomics asking them to look into the economic incentives that govern health-care. Guess if I was thrilled when I found these two recent gems (although I can’t take any credit):
Freakonomics delivers as always with a fresh, interesting scientific perspective. As a supporter since a few years I want to recommend these to anyone interested in the topic. As I have written earlier, I find it perplexing that so many arthroscopies are being performed while so much evidence is pointing against this. There is probably a vast combination of incentives that result in this, these podcasts provide some nice insights.
My htmlTable-function has perhaps been one of my most successful projects. I developed it in order to get tables matching those available in top medical journals. As the function has grown I’ve decided to separate it from my Gmisc-package into a separate package, and at the time of writing this I’ve just released the 1.3 version. While htmlTable allows for creating plain tables without any fancy formatting (see usage vignette) it is primarily aimed at complex tables. In this post I’ll try to show you what you can do and how to tame some of the more advanced features. Continue reading →
Costa et. al. performed recently a multi-center study including 18 trauma centers throughout the United Kingdom. They randomized patients with distal radius fractures to volar locking plates or Kirschner wires. They managed to randomize 461 patients and follow-up 90% after 1 year using self-reported scores. They could not find any difference after 1 year regarding their primary outcome, PRWE-score (−1.3 points, 95% CI -4.5 to 1.8). This was well below their stipulated minimally clinically important difference of 6 points. Could this be the end of the volar locking plate era? Continue reading →
Today is a good day to start parallelizing your code. I’ve been using the parallel package since its integration with R (v. 2.14.0) and its much easier than it at first seems. In this post I’ll go through the basics for implementing parallel computations in R, cover a few common pitfalls, and give tips on how to avoid them. Continue reading →
One, never-ending thread on this blog seems to be the degenerative meniscus. Gauffin et al. recently published a randomized controlled trial comparing surgery vs physiotherapy with favorable results for surgery regarding pain. Could this be the turnaround for one of the most controversial, but common orthopaedic procedures? Continue reading →
Surgical treatment for trigger finger consists of cleaving the A1 pulley, a simple procedure, considered to be low risk. Even so, there can still be scar tenderness, nerve injury, tendon bowing, and infection. It is therefore nice to see Wojahn et al.’s paper on long-term follow-up after cortisone injections. Injection is a simple alternative that consists of an injection angling 45° distally at the A1 pulley with 1 mL 40 mg/mL Depo-Medrol. Continue reading →
Nordenvall et al.  recently report in PLOS ONE an interesting study on cruciate ligament (CL) injuries where they could not find any protective effect on knee osteoarthritis (OA) from reconstructive surgery. It is a nation-wide study based on > 60,000 patients where they used the National Swedish Patient Register in order to find ICD-codes and surgical procedures code to identify patients with CL injury and those with a subsequent procedure. While the early results showed slightly less OA, there was an increased risk of 1.4 (95% confidence interval, 1.2 to 1.7) after > 10 years for those with surgery. Continue reading →
I love the study from McDowell et al. where they tested different methods for keeping casts dry. It is simple but takes up a both common and important issue that we doctors frequently forget about. They compare six different methods and it seems that double plastic bags secured with duct tape provide the best protection for the money. Continue reading →
In my previous post I wrote about the importance of age and why it is a good idea to try avoiding modeling it as a linear variable. In this post I will go through multiple options for (1) modeling non-linear effects in a linear regression setting, (2) benchmark the methods on a real dataset, and (3) look at how the non-linearities actually look. The post is based on the supplement in my article on age and health-related quality of life (HRQoL). Continue reading →