A new study in Clinical Chemistry investigated the errors rates for Point-of-Care (POC) devices:
Can you guess what the error rates were?
-----
(Or, if only some surveys are based on accuracy, then what are the other surveys based on?)
Posted by Sten Westgard, MS
There's an article that appeared in the October 2010 issue of CAP Today that probably didn't get enough attention. It covers a subject that's been gnawing at us for a while:
Accuracy-based Surveys carve higher QA Profile, by Anne Paxton
For those of you who thought all proficiency testing was "accuracy-based", this article may give you a bit of a shock. In fact, most PT surveys - indeed most EQA programs and even peer-group programs - are not based in accuracy. Instead, those surveys are only based on "consensus."
What's the difference, What does it mean - and how did it come to be this way?
-----
Posted by Sten Westgard, MS
In the iconic western film, The Magnificent Seven, there is a famous scene about marksmanship. [Quick set up: The Magnificent Seven are - you guessed it, seven - gunmen hired to protect a peasant village from a much larger group of bandits] Early in the film, the heroic gunmen detect three bandit scouts and want to capture them. In an abrupt exchange of gunfire, two bandits are killed, but the third bandit mounts his horse and attempts to escape. As the bandit flees, one of the gunmen, Britt, steadies his pistol and takes aim. The escaping bandit gallops farther and farther away. But just as he is about to disappear behind a hill, Britt shoots, hitting the bandit square in the back, killing him. The youngest of the gunmen, Chico, shouts:
Chico: (in awe) That was the greatest shot I've ever seen!
Britt: (sternly) The worst! I was aiming at the horse.
This scene reminds us that even when what one person thinks is great performance may not be acceptable by another person's standards. Indeed, what appears like an accomplishment may actually be an error.
And what, you may ask, does this have to do with Six Sigma?
-----
Posted by Sten Westgard, MS
As we write, the National Basketball Playoffs are underway. The home team for Westgard QC, the Milwaukee Bucks, just went down to defeat in the final game of a 7-game series.
Those who follow basketball know that in a series like this, the teams basically alternate home court advantage. The Bucks went to Atlanta to play the Hawks for two game,s then the Hawks came to Milwaukee to play the Bucks for two games, etc. But while there is a home court advantage in the audience (which didn't work: both teams won away games), the courts in every stadium are the same. The basketball hoop in Atlanta is the same as the basketball hoop in Milwaukee. Why is that?
Because the rules specify a consistent goal. The NBA has a rule book which states the precise size of the court, equipment and basket size. A basket, for example, "shall consist of a pressure-release NBA approved metal safety ring 18" in inside diameter with a white cord net 15" to 18" in length." Every stadium must comply with this rule.
Likewise, there is a single standard for the basketball: "The National Basketball Association (NBA) allows only one official ball: The ball must be the official NBA game ball manufactured by Spalding. The ball is orange in color, 29.5 inches in circumference and weighs 22 ounces (size 7). It must also be inflated to between 7.5 and 8.5 pounds per square inch."
Sorry for the long prologue. But wouldn't it be nice if labs were the same?
-----
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
While we recently got a study that estimated the (frightenly high) number of Adverse Events caused by US hospitals, it looks like other countries are not content to let us stand alone. Now Sweden is doing us one better. Guess what the Adverse Event rate is in one hospital in Sweden?
- 28.2%
- 20.5%
- 6.3%
- 3.32%
Which number would you choose?
-----
Posted by Sten Westgard, MS
Two interesting abstracts and papers concerning HbA1c came out recently. As laboratories switch from fasting blood glucose to HbA1c to diagnosis diabetes, the importance of the method performance of HbA1c methods is becoming critical.
But what's more important? Bias or CV?
-----
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
Posted by Sten Westgard, MS
I was looking over a recent study of a compact blood gas analyzer conducted over multiple sites, multiple cartridges, multiple days, etc. In other words, this was a study that was doing a very thorough job.
Then I reached a section where suddenly it all fell to nonsense: measurement uncertainty.
So they calculated measurement uncertainty, but then they compared the results against Ricos desirable imprecision performance specifications.
Huh?
-----
Posted by Sten Westgard, MS
In Biochemia Medica, a recent article detailed the Minimum requirements for the estimation of measurement uncertainty:Recommendations of the joint Working group for uncertainty of measurement of the CSMBLM and CCMB.
Can you guess how many?
-----
Posted by Sten Westgard, MS