Causal opacity
Medicine as a science is predicated on causality. We seek
to understand the causes of disease. Similarly, in the field of patient safety,
we aim to determine the causes of adverse outcomes: What factors led the nurse
to administer the wrong dose of heparin to Mr. Smith? What caused the surgeon
to operate on the wrong knee? Using root cause analysis, we can work backwards
from the adverse event to determine the underlying causes.
Now consider the case
a of 24-year old man hospitalized for 3 months following multiple, life-threatening injuries following a motorcycle crash. He required 17 operative procedures, a 4-week ICU stay, and had numerous invasive devices (including central venous lines, endotracheal tube, urinary catheter, ventriculostomy catheter, arterial line, and external fixating devices). On
hospital day 93, he develops MRSA bloodstream infection. The magic question is this: when was MRSA transmitted to this patient? And, of course, in cases such as
this, we are never able to answer that question. The field of infection
prevention is plagued by causal opacity—we are rarely, if ever, able to connect
cause to outcome in non-epidemic healthcare associated infections.
In infection prevention, causal opacity is the result of two
factors. First, the transmission event is silent since the pathogens are
invisible to the eye. Second, the incubation period temporally separates cause
from effect. With multidrug resistant organisms, the intermediate state of
colonization, which can extend for very long periods of time, can separate
transmission from onset of infection by months or even years.
Causal opacity also negatively impacts hand hygiene compliance. Imagine
if you failed to wash your hands, examined a patient, and the infection in the
patient manifested within seconds after touching the patient. Like an instantaneous electric shock, the immediate
feedback would probably keep you from ever failing to wash your hands again. Recently, causal opacity has hampered our ability to
understand why currently available personal protective equipment may be failing
us in caring for patients with Ebola virus infection.
The end result is that causal opacity makes it harder to hold persons and
systems accountable with regards to infection prevention. Yes, causal opacity sucks. But it’s an integral part of what we
signed up for. Otherwise, we’d all be cardiologists or
Fantastic article. What are your thoughts about the issue of causal opacity and the recent developments with Medicare reimbursements? Won't tracking back to the source of infection play a significant role in at-risk or low-performing hospitals as they work towards lower infection rates? I would imagine this is a very difficult obstacle.
ReplyDeleteLack of reimbursement by Medicare certainly raises the stakes, but for any given infection the problem of causal opacity is still present.
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