The seventies was an interesting decade to say the least. Bellbottom pants, platform shoes, long hair, and necklaces were the fashion of the day, and that wasn’t even the girls.  It was also the decade of technology, a technological boom that would never be equaled.  Slide rulers were replaced by calculators, analog watches were replaced with digital watches, music became portable with Walkmans,  your phone could be carried around the house, you could record missed calls, and you could punch a button and change the channel of your television.  Radio Shack and Texas Instruments would soon rule the business world Life was good.

I studied mathematics in college and learned about imaginary numbers. The simplest imaginary number i is equal to the square root of negative one.  The thing about imaginary numbers is that they do not exist, they are imagined.  But once you define the thing your imagination has imagined, you can do things to it. You can multiply it and divide it and tell others about it.

John Nash is the Princeton mathematician about whom the movie Beautiful Mind profiled.  Nash created an economic model about game theory and he was awarded the Nobel Prize for work showing that when multiple players are involved, for the group as a whole to win every player must choose a path that is not optimal for them, but that also does not put them in a losing outcome.  They must choose a suboptimal outcome, one that allows everyone to benefit. Part of his equation is shown below.

The point of showing this equation is to recognize that if any single variable is removed there is no equation.  By definition, both sides of an equation must be equal.  A missing piece invalidates the whole.

Health systems have their own mathematics and their own imaginary number i.  It is most frequently imagined and used to calculate Patient Experience; cal it PXi.

The traditional mathematical patient experience equation is the following, and you can tell others about it and make believe it is real:

PXi = HCAHPS (experiences of inpatients in the hospital)

Problem solved—not so fast Skippy.  The health system formulation of PXi fails because it does not include many of the variables comprising patient experience. It does not include a single experience that happens prior to treatment and after treatment. Oh, and it does not include the experiences of the majority of a health system’s stakeholders; namely outpatients, discharged patients, former patients,  family members, and the largest group of all, consumers—prospective patients.

So the real formula for patient experience is:

PX = (hospital experiences for inpatients and outpatients) + (stakeholder pre and post-hospital experiences)

Please notice there is no i in the real formula because the formula no is longer an imaginary number.  The PXi formula also fails because its calculations are based on measures tied to what CMS feels are important.  Although HCAHPS claims to represent the experiences of patients, the single most important measure missing from the CMS formulary is it does not include the perspective of a single patient. Nobody every validated the survey questions against what patients feel makes a good experience.  And therein lays the rub.

Although imaginary numbers have their place in mathematics, they are of little value in healthcare.