Site Meter Family Medicine Notes

October 29, 2005

links for 2005-10-30

Posted by Jacob Reider, MD at 09:18 PM |

October 27, 2005

EBM?

So I'm having dinner tonight with this group of happy medical students and they are bummin out about their EBM course and they ask me if I really use "EBM" and I say yes and then I do this little strep throat thing like this:

I see an adult in the office with a sore throat.  No kids.  No contact with kids

So I assume pre-test probability of about 5% Yeh - I made it up.  I'm probably close.

And the sensitivity of the test I'm doing is 85% (possibly better -- but we'll be safe)

Specificty is very good - 99%

So let's do the poor man's version that I use to explain to the patient:

You have a 5% chance of having this BEFORE I do the test - so after the test you have a 15% chance of the 5% chance of having strep throat.

.15 x .05 = .0075 ... let's round it up to 1%.

"Mrs Jones - you have a 1% chance that you have strep throat after this negative rapid-strep. Go home and drink warm tea with honey and you will feel better soon." (ok .. go find the evidence for THAT!)

---------

Students get confused.  "That's too easy" they seem to say. "We have to do all of those crazy calculations."

No - just understand.  I say.  Do the math and you'll get the same result here.

So here goes.

Given my number above - we need to calculate the Negative Likelihood Ratio - which is:

Negative Likelihood=(1-SENS)/SPEC

So:  (1-.85)/.99 = 0.15  

So our negative Likelhood Ratio is .15 = 15%

Now we need to relate this to our patient.  For this - the EBM disciples use the Fagan Nomogram which really uses the formula:

Pos-test odds =  Likelihood Ratio x pre-test odds

So ... Post-test odds = 15% x 5%

which is the same as

15 x .05 = .0075 ... let's round it up to 1%.

Look familar?

 

 

 

 

 

Posted by Jacob Reider, MD at 01:26 AM | | Comments (3)

October 24, 2005

VOIP, SwitchVox, SSL

We are getting very close to the day that we go live with our new phone system at the office.  Still a few bugs to work through .. but I've had enough random requests for the status - ever since I posted my review of SwitchVox that I do owe a bit of an update.

Here goes

The software is good, and we've been getting help from the tech support staff at FourLoop throughout.  There remain some wrinkles here and there, but updates seem to be coming at a pretty good clip - so I expect things will continue to improve.  

What sort of rough edges?  Well - the features of the software have come along well since the publication of the manual in June - and the help system that is embedded in the software is good.  But the documentation hasn't kept up with the features of the product - and this is sometime frustrating. It takes a while to "get" the best method for creating a really good IVR - and I wish that there were examples of more complex IVRs in the documentation - especially how to use the "option" functions.  Here's how (I think) it works:  Create an IVR.  Have step 1 be "play a sound" such as:  "choose 1 for eggs and 2 for peanut butter."   Now choose "options" and tell SV where to go when the user chooses Option 1 or Option 2:

Yes - it really is easy-as-pie.  And I THINK this is the way I'm supposed to do it .. but nothing in the documentation leads me there.  Some of this makes perfect sense and is very powerful-yet-simple (an awfully challenging combination to create) but the simplicity gets the upper hand in some places of the IVR - especially where it comes to the handling of options - and the handling of conditional clauses.

Having "options" stuck at the bottom of an IVR means that they HAVE to be the last thing that a user encounters.   While it's possible to develop a complex IVR that sends the user right to the end .. and then based on the option chosen - back up to a step above - this gets confusing quickly.  It would be much more intuitive to have the "options" behave like any other IVR action - since they are really just a "case" statement.  

And speaking of logic - the conditional clause is GREAT .. except it's only part of what I'd expect to see in a conditional clause.  I want ELSE and OR and AND and ELSEIF.

Ok.. enough complaining.

Josh and his team built something that I LOVE - and it's easy to use too.  It's a URL that I can put into web applications that causes the system to do something.

Here's the documentation for how it works:

 

What is the Call API?
The Call API provides a web interface for originating calls through the PBX. This is often called click-to-dial, and is done by requesting a specially fomulated url from the pbx.

How does it work?
Below is an example URL and a description of its functionality.

Originating a call Example URL:
https://IP.OF.PBX/api?cmd=call&extension=104&number=918005551212
cmd=call Tells the PBX this command is a call origination command
extension=104 What extension to ring on the PBX system 
number=18005551212
 When the call is answered by the extension this will be the number it will try to ring

How do my Call API Settings effect the call API?
The Call API settings allow the pbx to modify requested phone numbers so that they correctly match what the system expects. For example, if you request that the API dial 8005551212, the Call API Settings will add a 9 and a 1 to make the number 918005551212, which will then be dialed by your phone.

 
 
 
So if I have a link on a web page of our mini-EMR with a picture of a phone .. and it links to the pbx and tells it to call 5551212 from extension 500 .. then it calls 5551212 AND rings x 500 at the same time. So from the patient's chart - I can click to call the patient instead of dialing.
 
Yeh - you've heard of "click-to-dial" and you are not so excited?  maybe the fingers need a little exercise?
 
Ok .. but ... say you need to call 1000 people over 4 days and let them know you have flu shots available and they can choose any of three saturday mornings to come in and get one.  How can you use the API to do THIS - you say?
 
Easy-as-pie:
 
Build a little application (I use coldfusion but you could use anything you like) .. and do the following:
 
  1. Build an IVR that plays a sound:  "Hi - you need a flu shot. If you want one - listen carefully.  You can come in and get one on any of the following days ...  Press 1 for November 63rd, press 2 for October 34th and press 3 for December 44th. If you are hearing this message on your answering machine, you may call us back with your choice by calling 111-1111"
    1. Since the IVR will know who is called - it will send the result back to the application with:
      1. Name of person
      2. Date they chose
      3. (or that nothing was chosen - so maybe we got the answering machine .. which is fine.  We'll set up a temporary route on a DID so that when people call back they will get right to the IVR.  No waiting for a human.
  2. Query the database for the people you need to call and their phone numbers
  3. Loop through the query and send the phone numbers to the phone system every 40 seconds or so (evenings .. so we don't clog up the phones during the day).
  4. In the morning - run a report from the application to see who was called - who responded (and how) and how many people we need to schedule for the flu clinic on Saturday.
This works fine and I tested both the IVR and the Coldfusion and it seemed like they would work well - but I didn't (until tonight) try to tie them together.
 
When I did I got a mean error that Coldfusion couldn't connect to the PBX and all I got was a cryptic connection error.
 
So I had to do a little research and finally figured out that I had several problems.
 
  1. Fourloop build SwitchVox to use SSL when you are logged in as the administrator.
  2. To use the call API - you need to use SSL
  3. The SSL certificate is self-signed which is fine since it's OUR server and I think I trust myself. 
    1. But that's a little annoying because the browser complains that it doesn't have that certificate and that the name of the certificate (pbx) isn't the same as the name of the server. 
    2. But it's not so bad because I can click on the little alert .. or take the 29 seconds to install the certificate on my computer.
  4. But Coldfusion can't click the little box so I will have to install the certificate on the coldfusion server to make it happy.  Steven Erat shows us here how to do that.  .. ok .. now that wasn't so hard.  (or was it?)
    1. But it still won't work.  See the comments on Steven's page.  Several people got through step 1 only to learn that step 2 still stopped it from working:  "I was wondering if you know of a workaround for CFHTTP when posting to https:// where the certificate name on the SSL does not match the host name.

      When attempting this, I receive an Error Detail of I/O Exception: Name in certificate `www.domainname.com' does not match host name `xx.xx.xx.xx'"

      Hmm .. looks like I have the same problem.


But I figured out the solution!  Since I know that the certificate is called "pbx" and I now have it installed on the application server (which in this case is the client - SwitchVox is the server) .. still follow? .. I make an entry in the "hosts" file of the application server called pbx and point it to the IP address of SwitchVox.

Now I run my test page and my cell phone rings (every 40 seconds!) and it tells me I need a flu shot and the browser window of the debugging test page says:

Explanation OK
Http_Version HTTP/1.1
Server Apache/2.0.48 (Fedora)
Status_Code 200

 Hooray!

So we have solved the problem of coldfusion having trouble with SSL and reporting a connection error: I/O Exception: Name in certificate.   First, Install the certificate on the Colfusion server.  Next,  make a "hosts" entry to fool cf into thinking that the name of the remote server is the same as the name in the certificate.

Posted by Jacob Reider, MD at 11:43 PM | | Comments (2)

October 23, 2005

links for 2005-10-24

Posted by Jacob Reider, MD at 09:17 PM |

October 22, 2005

links for 2005-10-23

Posted by Jacob Reider, MD at 09:22 PM |

October 20, 2005

Avaya SoftPhone

Avaya is giving away their SIPSoftphone for free.

Posted by Jacob Reider, MD at 09:29 PM |

Gianotti Crosti Syndrome

I saw a child in the office yesterday who didn't have Gianotti Crosti Syndrome. The hallmark of Gianotti Crosti is that the rash is papular. My patient had no papules.

Posted by Jacob Reider, MD at 10:41 AM |

Amoxicillin and tooth enamel

Here's another reason not to use too many antibiotics. Published last week (sorry I'm so late on this one!) in the Archives of Pediatrics & Adolescent Medicine.

Posted by Jacob Reider, MD at 09:17 AM |

October 19, 2005

links for 2005-10-20

Posted by Jacob Reider, MD at 09:20 PM |

October 17, 2005

FMDRL

Putting the finishing touches on version 1.0 of the family medicine digital resources library.

Interested in beta testing?  Leave a comment here and I'll make you an account.

Posted by Jacob Reider, MD at 09:30 AM |

Flock - More web 2.0?

Somehow I  got an invite to download Flock, wich is a remarkable little application.  It's both a Web browser and a blog editor.  the Web browser is reasonably functional and it seems speedy enough.  A cool feature is that in a blog editor window, a menu bar can load all of your recent flicker photos.  Here I am last winter in Mexico making a sand angel:
 Flickr Photo
Some other things that seem to be very easy include a mechanism for easily adding links to blog.

I'm using it now.  Can you tell?

Audio Digest gives away a free medical education MP3 every month. Here's the one for October.  Not bad.


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Posted by Jacob Reider, MD at 04:57 AM |

October 16, 2005

Remember The Milk, Web 2.0 in healthcare

Remember The Milk is a well-done "web 2.0" application. So far, it's free - and I do like the user interface. I like the way that it will send an e-mail reminder AND a reminder to my pager AND a message to my gtalk client. Too bad there are no "web 2.0" applications for healthcare. Yeh - I'm not quite sure what web 2.0 means either .. but it seems that the focus is on usability, RIAs and AJAX. The whole AJAX thing is funny - as it's great to see people finally "get it" .. but the techniques for creating web applications that allow the user to interact with the server without reloading the page have been around a long time. I think the first well-written article on how to do this was the old "gif as a datapipe" trick - well before XMLHTTPrequest. We used this technique in the development of oncalls five years ago! Yet none of the EMRs are using these techniques. So sad to see us lag behind the rest of the world (again). With the emergence of standards for EMR interoperability - I dream about the back-end agnostic web-based EMR front end. Hmm ... It would be developed with a clean UI - and deliver the core functions of a modern EMR: - Messaging (provider to staff, patient to provider, staff to patient, patient to staff). - Order Entry (referrals, labs, procedures) - integrated with knowledge resources and CPT/ICD-9 lookup tools - Chart Note Entry - with templates and macros and voice recognition support - Prescription Writing - integrated with interaction checking, dosing guidelines, etc. - Immunization & Health Maintenance data entry & alerts - Disease management decisions support (HTN, DM, Hyperlipidemia, etc) It's really not too much to ask - is it?

Posted by Jacob Reider, MD at 07:41 PM | | Comments (5)

EBM for the busy physician

Chris Cates' website  provides wonderful essays on evidence-based medicine. I love his graphical depictions.  Here's an example:

statins and diabetes Kinda makes you think twice about using statins reflexivley in these patients - eh?

Posted by Jacob Reider, MD at 10:12 AM |

October 08, 2005

Google RSS reader

Google RSS Reader Cool. Useful? Maybe.

Posted by Jacob Reider, MD at 09:42 PM |

October 04, 2005

Peanut Allergy

Here's an exccellent review of peanut allergy.

Posted by Jacob Reider, MD at 02:29 AM |

Google and Sun = GoOpenoffice?

This one is going to be big.  Look out Bill. Openoffice is good.   OpenOffice+ Google (filestorage?  Integration with Gmail and google Desktop? = Great.)

Posted by Jacob Reider, MD at 02:24 AM |

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