Sensitivity and Specificity Explained Using Retired Nurse Syndrome.

Sensitivity and specificity is rarely a topic of great excitement for clinical physicians.  Trying to explain statistics to a physician is like trying to explain cirrhosis to an alcoholic.  Most have no idea what you're talking about and most simply don't care.  So Happy is here to help explain sensitivity and specificity using never before released  data he has collected over his fascinating decade of hospitalist work.  What better way to get physicians excited about sensitivity and specificity statistics than to use a combination of never before described rare pathology (including a form of fibromyalgia)  in combination with the most exciting patient population of all times:  the retired nurse.   But first, I must say, through my nearly ten years of travels as a hospitalist, I've seen my fair share of unusual allergies.

There was  that time with the allergy to horses, employment and prednisone.   In these situations, I implore  hospital utilization specialists to  use Happy's proprietary  ALLERGY:OBSERVATION ratio calculation when trying to determine whether the patient is inpatient or observation status.   This formula will help keep all hospitals in compliance with the  Recovery Audit Contractor (RAC) programs that are looking to steal money for their own riches.

Now on to my sensitivity and specificity explanation.  I have kept track of ten years worth of data that suggests the presence of phenomenon not previously described in any major medical publication.  You won't find this data in the New England Journal of Medicine, the Journal of the American Medical Association or in the Archives of Internal Medicine.  Nope, you'll only find this ground breaking research here at The Happy Hospitalist.  What is this fascinating medical oddity I have discovered that can further help define the appropriate inpatient vs outpatient status of the patient.   I present to you the Numerous Unusual Intermittent Strange Allergies and No Clear Explanation (NUISANCE) syndrome.  NUISANCE syndrome, when diagnosed in combination with  systemic fibromyallergia, is 100% sensitive  and over 98% specific for its association with being a retired nurse.

I've taken the liberty of aggregating ten years worth of consecutive hospital discharge data into table form below to help you understand how to interpret sensitivity and specificity data and I'm using my ground breaking research to engrave medical statistics into your physician mind forever.  You will never again forget how to interpret sensitivity and specificity data if you can remember how it relates to NUISANCE nurses.  In the table below, disease is defined as the presence of NUISANCE syndrome in combination with  fibromyallergia.  The test is whether the patient is a retired RN or not.

 250,000 patients  TEST:  Retired RN?  (Yes) TEST:  Retired RN? (No)
Disease  PRESENT 1,000 (a) 0            (b)
Disease ABSENT 4,000 (c) 245,000 (d)

The sample size of my research is an astonishing 250,000  consecutive discharges over 10 years.  That's a lot of hospital discharges.  As you can see,  the prevalence of disease is quite low at only 0.4% (1,000/250,000).  But because of the large sample size, I was able to confirm 1000 cases of combined NUISANCE syndrome and fibromyallergia.  As you can see from my data, in every single case of this new but rare disease, the patient was a retired nurse. 

Shocking, I know.  Statistically, what does that tell us about retired nurses and their association with combined NUISANCE + fibromyallergia syndrome?  Let's review a little statistics, shall we?  Remember your sensitivity and specificity tables.      I've taken the liberty to include a,b,c,d in the table above for your calculations below..  Here are the sensitivity and specificity formulas for your review.  Dig deep into your medical school days and regurgitate the following:

Sensitivity formula:  a/(a+b)
Specificity formula:  d/(c+d)
False Positive formula:  c/(a+c)
False Negative formula: b/(b+d)

From my data, you can see that being a retired nurse has 100% sensitivity and over 98% specificity as a test for combined NUISANCE syndrome + fibromyallergia.  It does however, have a very high false positive rate of 80% (c/a+c) and a false negative rate of 0%.

In other words, if you have combined NUISANCE syndrome + fibromyallergia, the test (whether you are a retired nurse or not) can be used to pick up 100% of the cases (100% sensitivity), but 4/5 times being a retired RN will not result in having the disease (high false positive rate).  And, if you have don't have both NUISANCE syndrome and systemic fibromyallergia , you are not going to going to be a  retired nurse over 98% of the time (high specificity) with no false negative reports.  

What's the take home message here? There are several.   I implore our national leaders to begin educating practicing nurses immediately about the dangers of retiring.  Just because so many aspects of the daily job make many want to quit, retiring puts nurses at risk of becoming a NUISANCE.    Nurses need to know these risks before making that  informed decision to retire.   For physicians out there?  Now that you understand the statistics of being a retired RN, you'll never forget how to interpret sensitivity and specificity analysis.  And I'm 100% certain of that.  Now, please enjoy a little original Happy Hospitalist ecard humor.

"Why do we call good results negative and bad results positive?  I'm positive there isn't an answer."

Why do we call good results negative and bad results positive?  I'm positive there isn't an answer ecard humor photo.


Some of this post is for entertainment purposes only and likely contains humor only understood by those in a healthcare profession. Read at your own risk.

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