Clinical risk

We all acknowledge that uncertainties in life are inevitable. They’re a product of the inherent randomness of  things, and can play-out either way: in our favour, as luck, or as misfortune. The ease with which we accept risk, and how it affects our decision-making, varies radically between individuals and cultures, and can change over time. In the veterinary context, risk, money, and patient welfare often combine to complicate clinical decision making.


Risk profile of the pet owner:

Amongst us there are those who ride motorbikes, share needles, and gamble at the casino; meanwhile others insure everything, vaccinate religiously, and don’t allow the kids to walk home from school. We can also sustain seemingly inconsistent attitudes to risk – I’m a cautious investor who frequently  enjoys the trill of risking physical injury on bicycle and motorbikes. Just as financial advisers look at the ‘risk profile’ of investors, theoretically, medical decisions should also consider the patient or pet owner’s attitude to risk.

Social amplification:

The accelerating pace of modern life is feeding the growth of anxiety disorders, and leaves us craving safety, certainty and control. In the developed world, deprived of the genuine mortal risks with which we evolved, starvation and predation, we run from shadows. Social amplification, by the media and within the community, can further escalate perceptions of menacing risk, unsupported by the stats.  Fear of crime sees more alarms and private security; ever escalating OH&S standards see us trying to control the uncontrollable; and a ‘baby on board’ demands a SUV chassis for protection – a car more likely to crush them in the driveway at age 2.



While not wanting to underplay the genuine threat of pandemic influenza, the recent collective hysteria surrounding Swine flu, long after mortality rates were confirmed to be lower than seasonal flu, is excellent example of social amplification on an institutional level: both the media, and departments of health. At least it offered the opportunity to test-run contingency plans for the real thing, and get some Tamiflu field-data pointing to gastrointestinal and psychiatric side effects.

Clinical uncertainties:

In the medical context there are more uncertainties than your doctor or vet may let on. The uniqueness of DNA in both patient and pathogen, and a cocktail of unknown environmental factors, brings intrinsic variability to all biologic systems.  We try to iron-out all this chaos by studying populations and confidence intervals, but uncertainty remains: as limitations of the technology or operator bias, as false positives and negatives, and subjectivity when reading images and pathology.  When your doctor declares your pap smear was negative and your X-ray was ‘all clear’, it’s rarely a dead certainty.

Balancing mathematical probabilities against costs of tests and treatments is sometimes a [email protected] for the vet, let alone explain to pet owners in street language. Our attitude to risk depends on both the chance and welfare impact of a bad outcome, and the financial cost of risk avoidance. A 50% chance of a side effect from my dog’s medication may seem more tolerable than a 5% chance of death during surgery, but if the medication is non-essential and surgery life-saving, suddenly the scalpel doesn’t look so threatening.  I may chose to treat my cats abscess medically for $100, rather than surgically for $400, even when there’s a 30% chance it wont work, while others, more cashed-up or distressed by their cat’s suffering, may choose the latter, eliminating the risk of an extended recovery.

There can be differences between how a vet and pet owner value certainty too.  A vet may need 98% certainty to declare a lump benign, while an owner, reluctant to spend on pathology, may be happy with 80% confidence based on visual examination alone.

Defensive Medicine:

In reality, such percentages aren’t so easy to quantify.  It’s easier, and potentially more lucrative, to adopt the practice of ‘defensive medicine’. In it’s most highly evolved form, the litigious US healthcare system, it involves two, arse-covering strategies:

  • diceyAssurance – doing lots of tests to eliminate, or at least minimise, the risk of misdiagnosis, inappropriate treatment, and bad outcomes. This has resulted in progressively larger ‘minimum data bases’.
  • Avoidance – referring ‘high-risk’ procedures to specialists who, virtue of extra study and heavy caseload in a chosen field, usually have better diagnostic equipment, skills and outcomes.

This style of diagnostic investigation and treatment minimises risk of unforeseen events and sub-optimal outcomes, but tends to be more costly. In the veterinary setting, defensive medicine is more frequently seen in circumstances where the stakes are high: complex and life-threatening diseases, and highly emotional or demanding pet owners. These factors often converge in consultations at emergency centres that now serve most Australian capital cities.


Risk for pet owners
  • Ultimately, in terms of risk, clinical decision-making comes down to how much risk can you afford to avoid.
  • If your cat’s very sick, you’re cashed up, and don’t want to risk cutting corners, tell your vet straight up – she can be thorough and refer early if necessary.
  • If your chronic gambling addiction keeps you in poverty, ask the vet for the approximate odds and you can place a wager on your Boxer’s tumour.

Other posts which touch on issues of risk include:

  • Pre-anaesthetic bloodwork – Is it worth it?
  • Heartworm prevention and testing – Can you be complacent?
  • Specialisation –  A trend that’s lifting the quality of care, as long as you can afford it.
  • Clinical brinkmanship – When self-interest interferes with good clinical decision making.
  • Leaky Bitch – Clinical decision making surrounding treatment of the incontinent female dog.
  • Preventative medicine –  From vaccination to tick prevention, it’s all about weighing costs versus benefits.
  • Thumbnail Audit of Adverse Vaccination Events, Australia, 2008

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