I often spend time on the phone explaining to potential new clients why causation is a necessary element of any medical malpractice claim. Washington is one of a handful of states that do not recognize punitive damages, so the only damages that can be recovered are compensatory. That means that, in order to have a viable medical negligence case, one must not only prove negligence but also what injury or damage was caused by the negligence. If you can prove those two elements — negligence and causation — then the jury can determine how much money is needed to compensate you.

The degree or extent of negligence is not determinative, even if the negligence is egregious. Nor will the amount of damages be determinative, no matter how serious the injury. Without the “missing” element of causation, you likely do not have a viable claim.

In order to prove causation, you will need expert testimony from a medical expert. Often the causation link is an easy one to make. A physician’s assistant inserts a tube to relieve pressure around a lung but mistakenly plunges the tube into the patient’s heart and he dies instantly. But often causation is much more difficult. An example is a case involving a delay in diagnosis or treatment.

At least once a month I get a call from someone who is angry that a fracture was missed in the emergency room, and surgery was later required to repair the fracture. Even with clear negligence in not taking an x-ray given the clinical picture, the claimant must prove that the delay in diagnosis and treatment caused a specific injury. Often that proof isn’t possible because, even with earlier diagnosis, surgical repair would still have been needed. When I explain that, the caller gets irate about how bad the ER treatment was, asking rhetorically, “you mean they can get away with such bad medical care?” I have to bring them back to the causation requirement and tell them yes, in our civil legal system they can get away with it.

Sometimes I use the analogy of a drunk driver running a red light. The negligence is outrageous and clear, but if the car didn’t hit your car but barely missed it, there is no lawsuit that can be brought. The claim that “I could have died” as a result of the bad care (or, in the driving analogy, a near miss from the drunk driver) doesn’t get you anywhere.

Washington now recognizes a claim for “loss of a chance of a better outcome.” That would seem to open the door to claims where it is difficult to show that a specific injury was caused by, for example, a delay in diagnosis and treatment. The problem is that, under present case law, the burden is still on the claimant to prove what percentage of a chance was lost.

That burden can be met in some cancer cases because there is literature about the five-year survival rate depending on a particular stage of a cancer. The claimant may be able to show, through expert medical testimony, that the cancer would have been at stage I when it should have been diagnosed — and thus the patient would have a 70% chance of five-year survival — but those chances dropped to 30% when the cancer was finally diagnosed as a stage IV. The jury then can use the statistics to calculate the loss of a chance of a better outcome. But if the claim is that the claimant has more breathing problems now because of a delay in treating his emphysema, it is doubtful anyone could come up with specific percentages.

So, in general, the answer to the question posed in the title is “yes.” You do always have to prove causation in a medical malpractice case.