Why medicine is not like a parachute

At the recent meeting of the American College of Chest Physicians I went to a session on hospital rapid response teams. This was a talk given by a senior and respected member of the Pulmonary and Critical Care academic community, well published and known. Now, if you are wondering what the heck is a rapid response team, I will tell you: it is a team composed variously of an ICU physician (or a hospitalist, depending on local patterns), a nurse or two, a pharmacist and sometimes other ancillary personnel. The role of this team is to be at the beck and call of the ward nursing staff to evaluate urgently any floor patient whose clinical condition may appear to be deteriorating. The ultimate goal, of course, is to avert a catasprophic emergency called a code, where the patient deteriorates to the point of needing emergent resuscitation.

While such a team makes a lot of sense, no study has convincingly shown that it does what it is meant to do -- either prevent codes or save lives. The presenter, a man quite invested in the sensibility of such teams, was making the point that perhaps we just have not focused on the correct outcomes to measure for this intervention. Ultimately, he said, we should continue to support such teams because of our gestalt that they work. After all, he went on, nobody has tested the effectiveness of the parachute in a randomized controlled trial.

When I heard this, I realized that I had been hearing this comparison a lot lately, of medical interventions to parachutes. And since his statement seemed somehow wrong to me, I started to think about why such an analogy is completely fallacious. And here is the startlingly obvious answer: the number needed to treat (NNT) for a parachute is 1! What this means is that one only needs to "treat" one person with a parachute (or strap it on before jumping out of a plane) to save one life. Now, is there really anything that we do in medicine whose margin of effectiveness comes even close? Last week we argued about a screening test with the NNT of 2,000. And we also talked about a therapy with a NNT of 16 which is not being utilized because of high costs.

So, let's not be intellectually lazy and let's not resort to comparing anything we do in medicine to a parachute. The parachute is made to mitigate the laws of physics, which are inherently more predictable, stable and generalizable than the laws of biology. Instituting a rapid response team may feel good to us, but, in addition to lending no measurable improvements to patient care, it may have the "unintended consequences" of abandoning patients who really need our attention at that moment to better their outcomes.

A similar argument can be made about many interventions whose mere face validity we take as God's own word. We and others have cautioned against such gullibility, particularly in a world that runs with half-truths and misinformation under the banner of quality measures. None of us has the cause to be so self-congratulatory as to compare our wares to the parachute. Now more than ever, experts need to think and present critically, soberly and objectively, lest we continue the trend of parochialism in our out-of-control disease care system.