Monday, July 10, 2017

Which Arm of the Trial Would You Pick?

For years, critics of opioid guidelines have argued that the absence of evidence on long term efficacy of opioids wasn't a sufficient reason to declare such long term use "medically unnecessary." Advocates of opioid therapy have been frustrated by the notion that because we didn't have a randomized clinical trial (RCT) showing the drugs to be helpful, we all assumed them to be harmful. While practical experience led to this totally plausible conclusion, detractors still saw hypocrisy in our dependence on documented medical evidence... that still didn't exist.

That RCT has finally arrived.

The study is to be published soon, but Dr. Erin Krebs recently presented her findings at the 2017 meeting of the Society for General Internal Medicine in Washington, DC.   You can read a synopsis and commentary in one of my favorite monthly medical newsletters, The Back Letter (subscription required).  Here's the key take-away:
Opioids provided no advantage in terms of function at the 12-month follow-up mark, and patients in the opioid wing of the study actually reported marginally more pain at 12 months than those in the non-opioid group.  
There are really two key points there: the first, that opioids don't appear to increase functionality, is obvious to most of us who have been living and breathing this issue for the last decade.  The second, though, refutes the most fundamental argument of opioid advocates - that the drugs at least control pain.  Turns out, they don't do a good job of that either.  To sum up, the opioid creates the exact opposite of its intended effect: it fails to increase function and instead actually increases pain.

Perhaps the most interesting characteristic of the study was its design.  It was randomized (patients are chosen by chance to participate in one or more clinical interventions - in this case, opioids for pain relief) and controlled (the clinical intervention was compared to a standard practice - sometimes placebo, sometimes not - as in this case - a non-opioid drug regimen).

But it wasn't blinded.  A blind trial indicates that the participants don't know which arm of the study they've been assigned to.  In this study, patients getting opioids knew they were getting opioids and patients not getting opioids knew they weren't getting opioids.  To me, that makes the results even more compelling.  Patients who knew they were receiving opioids to manage their pain still reported higher pain levels at the 12-month mark.  And patients who knew they were not getting opioids still reported increased functionality vs. the opioid group.

Apparently, there was some ethical debate regarding this study before its launch. It was assumed by some that such a trial would be impossible because people in chronic pain would simply refuse to join the non-opioid arm of the trial if that's where they were randomly assigned.  Further, some assumed it would be unethical to not provide opioids to people in chronic pain - that by instituting a non-opioid control group, patients would be deprived of necessary medical care.

As it turns out, the arm of the trial some ethicists assumed would be, in the first place, impossible to fill, and secondly, inhumane... well that's the arm of the trial you actually wanted to be in.

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