Prius non tempore: first, do no time

The golden rule of surgery is: Primum non nocere - ‘First, do no harm’. There is another, competing rule that comes from practicing defensive medicine: Prius non tempore - 'first, do no time'.

Primum non nocere boils down to avoidance of acts that do more harm than good. Such acts (interventions) are determined by balancing the risks and benefits. Basically, it’s a no-brainer. But when the risks and benefits are uncertain, two biases kick in: the tendency to act (to see inaction as failure) and to overestimate the benefits and underestimate the harms of our acts, either because we have a slanted view of the evidence or because the lottery mentality takes over and we distort the probabilities of risk and harm. All this means that we may be choosing interventions that cause more harm than good. I say ‘interventions’ because it is not limited to treatments, it includes diagnostic testing and screening.

Another forces that pushes us to intervene in the presence of uncertainty is a well known but little discussed maxim: Prius non tempore: first, do no time. In other words, in the presence of uncertainty, take the course that is least likely to get you sued.

Blamed for some of the overtreatment and overdiagnosis that plagues modern medicine, prius non tempore, also known as defensive medicine is, at times, a strong driver of surgical practice. Although it can involve not treating people (e.g. high risk patients), defensive medicine usually involves overtreating or overinvestigating, and it has been shown to increase health care costs and to increase patients risks, rather than reducing medical error (here and here). In fact, because defensive medicine prioritises the avoidance of legal action over balancing the relative risks and benefits for a patient, defensive medicine is a form of medical error.

Action versus inaction
Choosing non-operative treatment is often seen as inaction, rather than a reasonable alternative course of action. It is seen as doing nothing rather than doing something, despite evidence that doing nothing can be better for the patient; it just doesn’t sound like something that would help. It is easy to paint a picture of non-operative treatment as neglecting the patient’s needs. This is another reason why we intervene, and why doctors are more likely to recommend certain treatments to their patients, but not have those treatments themselves.

Two maxims in conflict
By definition, defensive medicine is in conflict with primum non nocere. But can you blame a surgeon for taking the course that is least likely to end up in court over the course that involves the somewhat murky art of balancing risks and benefits? The legal support for such activity reflects the gambling mentality that makes the high likelihood of harm (the cost of the bet) seem small compared to the potential benefit (the jackpot). People tend to focus on the prize (cure, relief) regardless of how remote the probability, and not on the cost (risks, harms). This applies to patients considering treatment as well as to judges and juries.

The pendulum is swinging
In the past, I was told that one was less likely to be sued for committing and act than omitting and act. Everybody loves the story of a hero surgeon who took a chance and threw the dice, especially when the chance of success seemed to be against all odds and the risks of harm were stacked against them. On the other hand, the surgeon who balanced the risks and harms and decided that the potential benefits did not outweigh the risks and suggested just letting nature take its course is seen as ineffectual and unheroic. Nobody likes a surgeon who doesn’t surge. This feeling was reflected in court judgements: rewarding the surgeon who ‘gave it a shot’ by playing on the lottery mentality of the patient, and punishing the surgeon who trod cautiously.

However, this prevailing sentiment is changing. We all know colleagues who have been sued for non-operative management of common conditions, but largely because of reports from experts who stated that the results of surgery would have been superior. More recently, I have seen cases where surgeons have been sued for surgery that has resulted in an increase (or failure to relieve) symptoms; for example, increasing knee pain after arthroscopy for a degenerative condition that was made even worse by a second arthroscopy. This time, the cases have proceeded because of reports from experts that state that the surgery was not indicated and the risks not justified.

But it is not the scientific evidence that is swaying the legal process directly – it rarely does. It is the increasing acceptance and knowledge of the scientific evidence by the surgeons who write the reports. The evidence has been there for a while, what we are seeing now is a culture change amongst practitioners – a change that is required to effect widespread change in the legal and clinical environment.