Tuesday, November 8, 2011

More Reasons to Discount Adverse Event Reports

            A topic of repeated interest for us is how courts treat evidence of adverse event reports.  And we haven’t been shy about how we feel -- AER's should not be used in a civil trial.  AER's are voluntary, biased (sometimes litigation-generated), and should not be used to calculate incidences of drug risk. AER's are not the stuff of good science.  We've even put together an Adverse Event Report Cheat Sheet  filled with cases laying out compelling reasons for excluding AER's.  

            So, why are we re-hashing this already well trod ground?  Well because in railing against the use of AERs in the courtroom, we’ve often distinguished the FDA’s reliance on AERs on the basis that the FDA can act in the public interest on a lower quantum of evidence than is necessary to establish causation in a products liability suit.  A recent report by the FDA, however, has left us wondering just how helpful AERs are to even the FDA.  The purpose of the report, entitled Understanding Barriers to Medical Device Quality was “to assess and understand gaps in medical device quality.”  FDA Report at 3.  While the FDA didn’t rely exclusively on AERs, they were a driving factor in the FDA’s apparent conclusion that medical device quality has significantly lagged behind medical device technology.  While we will leave a more thorough discussion of the four corners of the report to our friends at the FDA Law Blog, we thought it worthwhile to point out how even the FDA’s use of voluntary AERs can lead to false conclusions.
 
For starters, the report states that AERs for medical devices are on the rise.  The FDA reports that “serious adverse event reports related to medical device use have outpaced industry growth by 8% per annum since 2001.”  FDA Report at 3.  The report then suggests that the increase in volume of AERs must mean a decrease in the quality of medical devices.  Huh?  Even the FDA had to admit that looking at the quantity of AERs can be misleading:
  
Several factors may contribute to the growth in volume of adverse event reports.  These include greater outreach by FDA emphasizing reporting requirements, along with greater manufacturer sensitivity to reporting requirements following notable recalls.  Some of this growth may also be due to growth in the number of medical devices in use.

FDA Report at 12.  That last one seems really obvious – if more people are using more devices, there are going to be more AERs.  But does that tell us anything about safety?  No.  So, it is not surprising that the FDA itself recommends “adjusting absolute numbers of adverse events and recalls for device usage, or the number of devices on the market.”  FDA Report at 38.  If the FDA has yet to make that necessary adjustment, then it hasn’t answered the real question – whether the number of AERs as a percentage of total device usage has increased?  And, if the FDA is reaching misguided conclusions based on misleading AER evidence, how can anybody suggest that juries won’t be similarly misled?  

            The other growth factors cited by the FDA – greater FDA outreach and heightened sensitivity by manufacturers – demonstrate another problem we have with using AERs to prove anything about causation in drug/device product liability litigation.  AERs are voluntary.  So, as the FDA Report suggests, manufacturers err on the side of over-reporting to avoid FDA enforcement actions.  So too do users over-report (by phone calls to manufacturer consumer service lines or by filing lawsuits) in the face of chiefly adverse publicity concerning this or that device/drug.   Where a manufacturer has been stung by a Warning Letter or the public has been inundated with ads about a product recall or a public health alert – AERs go up.  The voluntary reporting bias is huge and it is another variable that should be controlled for if AERs are going to be used in safety analyses.  Also, it contradicts plaintiffs’ experts’ theory that AERs are under-reported and therefore, if anything skewed in favor of defendants. 

            The FDA Report also states that AERs are not evenly distributed across all medical devices.  Rather, “cardiovascular, in vitro diagnostic (IVD), and general hospital/surgical devices account for nearly 60% of adverse event reports.”  FDA Report at 3.  Really?  Is anyone surprised that cardiovascular devices “have increased as a share of total serious adverse event reports even faster than for adverse events overall.”  FDA Report at 15.  Could it because the cardiovascular patients are generally older and less healthy than the population as a whole and therefore more likely to experience an adverse event?  Remember, AERs are generated without regard for cause.  So, can we draw any meaningful conclusion about the safety of cardiovascular devices without accounting for the unique patient population?  No.  Again, the raw numbers are misleading.

            The FDA purports to “possess a wealth of data pertaining to medical device quality. . . [that] may be used to quantify the magnitude of medical device quality problems and to better understand the root causes of these problems.”  FDA Report at 38.  But what they really have is a stack of voluntary, selective, biased reports that a device may have caused or contributed to an adverse event.  So, perhaps the most important takeaway from this report for those of us in the drug/device litigation arena is the FDA’s almost-admission that more is needed for AERs to be meaningful:

Bolstering the data that FDA currently collects with a few key additional pieces could greatly increase its utility and provide a fuller view of medical device quality.  Gathering additional risk data from companies will likely paint a clearer picture of the associated level of risks for devices.

FDA Report at 38.  So, until the additional data is collected, the current picture remains murky at best and murky isn’t good enough in the courtroom.