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Sham knee surgery study

Common knee surgery does very little for some, study suggests
by Pam Belluck, New York Times, 25 December 2013

The article concerns an arthroscopic procedure on the knee to repair a torn meniscus. According to the article, about 700,000 such surgeries are performed annually, the most for any orthopedic procedure. But is the procedure actually beneficial? The study described here was conducted in Finland; it involved 146 patients, aged 35 to 55, at five hospitals. All of the subjects were underwent arthroscopic procedures, which involve making and incision and inserting a scope to assess the injury. However, at this point, it was randomly determined whether the meniscus would actually be trimmed or if a false blade would be rubbed simply rubbed on the knee cap as a sham treatment.

The following quotation comes from a related story in the Wall Street Journal:

"Doctors have a bad tendency to confuse what they believe with what they know," said Dr. Järvinen [one of the study's authors], an orthopedic resident and adjunct professor at Helsinki University Central Hospital.

The WSJ article also included the following graphic

Submitted by Paul Alper

The Distributome Project

The Distributome Project is a collection of web-based resources for teachers and students of probability, statistics, and partner disciplines.

The heart of Distributome is a digital library of special, parametric probability distributions. Properties of distributions, and relations between distributions, are stored in an XML database. Properties of a distribution include density, distribution, quantile, and generating functions; various moments, such as mean, variance, skewness, kurtosis, and entropy; median and other special quantiles; and so forth. Relations between distributions are classified in various standard ways, such as special cases, transformations on underlying random variables, limits of random variables or parameters, and conditioning.

Built from the database are a number of innovative features and ancillary resources:

• The Navigator is a dynamic, graphical interface in which the distributions are represented as nodes and the relations as edges between nodes. Clicking on a node shows the properties of the distribution, while clicking on an edge shows the relationship between the corresponding distributions.
• Interactive simulators and calculators are available for most common distributions. A simulator illustrates a distributions in a visual and dynamic way, often with the help of randomizing devices (such as coins or balls) or an underlying random process. A calculator can be used to compute values of the distribution function or quantile function.
• The Distributome Blog is a collection of activities that use probability distributions to model and solve problems in a variety of applied areas, often with real and historically interesting data sets. Each activity includes an overview, goals and problems, and hints and solutions. For example, the Homicide Trends Activity involves fitting a Poisson distribution to homicide data, based on a news story from the Columbus Dispatch.
• The Distributome Game challenges students to identify the correct probability distribution for a given problem statement. The game is timed, and is in the form of an array, with problems statements in the rows and distributions in the columns. Various settings are available to custom the game.

The Distributome project is freely available, open-source, and is built on standard web technologies. It is supported through grants from the National Science Foundation (grants 1023115, 1022560, and 1022636).

Submitted by Kyle Siegrist