Tort Law - Causation Flashcards
A patient was in hospital being treated for heart disease. A nurse misread the consultant’s notes and negligently prescribed the patient incorrect medication (the breach). The patient suffered from a cardiac arrest and subsequent brain damage. Medical evidence suggests that the cardiac arrest was caused by either the heart disease or the breach.
Question: Is factual causation satisfied?
No, because the two causes are equally probably - 50%.
In order to satisfy the “but for” test, the probability of the harm being caused by D’s negligence must be 51% or higher.
A patient undergoes an operation on their face that carries a 5% risk of causing permanent scarring. The risk materialises. The surgeon did not inform the patient of the risk prior to the operation.
Question: Could this satisfy causation?
Answer: Factual causation is satisfied if the patient can show that they would not have had the operation or would have deferred the operation to a later date had they been told of the risk.
How do we determine if there are multiple causes of C’s harm?
For example:
- Underlying health condition (20%)
- C’s existing asthma (20%)
- C’s brittle bones syndrome (20%)
- D’s negligence (40%)
In negligence cases, D must be able to prove that D’s negligence ALONE satisfies the “but for” test. (i.e. D’s breach alone would have caused the harm, with 51% likelihood or above).
For example:
- C feels ill and sees the doctor. He ignores C and sends her home.
- C suffers a heart attack that, even with the doctor’s intervention, would have a 49-50% chance of killing C.
- In this case, the doctor is not negligent because even if he had treated C, there was a 51% chance of C dying.
In other terms, but for D’s breach, C STILL would have suffered the harm.
- Underlying health condition (49%)
- D’s negligence (51%) = D was negligent as he satisfies the “but for” test.
If a doctor or other medical professional fails to inform C of the risk of a procedure - how do we determine factual causation?
The “but for” test still applies based on the balance of probabilities:
C must show on the balance of probabilities (51%+) that, had they been warned of the risk: (i) they would not have had the surgery, or (ii) would have deferred the surgery to a later date.
What happens if the “but for” test cannot be satisfied? Are there rare exceptions where the court will STILL find factual causation?
Yes, there are 2 exceptions:
(1) For cumulative / multiple causes that work TOGETHER: the “material contribution” test.
(2) For non-cumulative / multiple causes: the “material increase in risk” test.
Where “but for” causation cannot be confirmed by experts, how do we deal with cumulative / multiple causes of harm that work together?
The “material contribution” test - where there are multiple causes of harm that operate TOGETHER to cause C’s harm.
Legal Test: On the balance of probabilities, did D’s breach make a MATERIAL CONTRIBUTION to C’s harm?
(cannot be a minimal / de minimis contribution)
For example:
1. Dust naturally occurring in C’s job.
2. Dust negligently caused by D’s breach of duty.
3. As a result of both 1 and 2 working together, C suffers a respiratory disease.
For example:
1. The natural progression of C’s medical condition.
2. Negligent lack of care by D’s breach. [2 operated together with 1 to produce C’s harm].
3. Medical experts could not say “but for”, but the claim succeeded on the “material contribution” test.
Where “but for” causation cannot be confirmed by experts, how do we deal with NON-cumulative / multiple causes of harm?
- Think: how is this different from cases where the multiple causes are cumulative (work together)?
The “material increase in risk” test - where there are multiple causes of harm that are different types / do NOT work together to cause C’s harm.
Legal Test: On the balance of probabilities, did D’s breach MATERIALLY INCREASE THE RISK of C suffering the harm?
For example:
1. C is exposed to dust naturally in his job.
2. D negligently exposes C to dust in his job due to breach of DOC.
- C’s harm (dermatitis) is not the result of the dust exposures working together cumulatively over time. For example, C could have suffered his harm due to even ONE exposure to dust, and we do not know whether that one exposure would have been tortious or naturally occurring. For this reason, the “material contribution” test cannot be satisfied.
- D’s breach satisfied the “material increase in risk” test: on the balance of probabilities, D’s breach MATERIALLY INCREASED THE RISK of C suffering dermatitis.
In what rare circumstances is the “material increase in risk” test used?
In what rare circumstances is the “material contribution” test used?
Material increase in risk - test is only used where “but for” causation is not possible on the expert evidence AND is confined to:
- industrial negligence cases, e.g. dust or asbestos.
- single agency cases, e.g. only dust, or only asbestos being sources of C’s harm, so long as D’s breach is involved in exposure.
Material contribution - test is only used where “but for” causation is not possible on the expert evidence.
(can be used for “multiple agency/causes”, e.g. where harm stems from (existing disease, D’s breach, physical injury, allergies).
How is causation handled in “loss of a chance” cases?
PURE ECONOMIC LOSS
C must prove there was a REAL and SUBSTANTIAL chance that they could have avoided the pure economic loss.
(EG: Due to solicitor’s negligence advice, claimant lost chance to negotiate)
MEDICAL CASES
The same as normal - “51%+ / balance of probabilities”, C would not have suffered harm, but for D’s breach.
Example:
- C falls out of tree. C develops necrosis of the arm.
- Due to D’s negligence, C’s arm is paralysed.
- If there was a 49% chance (or less) that this would have happened regardless of D’s negligence, C’s claim must fail.
C must have had a 51+% chance of survival / not suffering harm to succeed on his claim.
A patient visits A&E with severe stomach pain. After a five hour delay, they are seen by a doctor and diagnosed with appendicitis. The patient requires immediate surgery, but just before the surgery begins, their appendix ruptures. In the course of the surgery, visible signs of infection are found in the patients body and medical evidence suggests they may have been there for some time. Medical evidence also suggests that the appendicitis and the delay contributed to the rupture and infection.
Question - pick the most accurate statement
A - There is a greater chance that the delay caused the rupture and infection than the appendicitis alone so factual causation is satisfied.
B - Factual causation fails as it could have been the appendicitis alone, not the delay, that caused the rupture and infection.
C - The delay materially increased the risk of rupture and infection meaning factual causation is satisfied.
D - Given the appendicitis and delay contributed to the rupture and infection, the material contribution test is satisfied.
E - Factual causation cannot be established as it cannot be shown that ‘but for’ the breach (the delay) the patient would not have suffered a rupture and infection.
Answer: D.
This is a case where medical science cannot establish the probability that ‘but for’ an act of negligence (the delay) the rupture and infection would not have happened. However, it can establish that the contribution of the delay was more than negligible (therefore the material contribution test is satisfied) (Bailey v Ministry of Defence [2008] EWCA Civ 883).
C would not apply because this is NOT an industrial disease scenario.
What is apportionment? When is it used?
Please give an example of what apportionment looks like in practice.
Apportionment is used once factual causation has been established.
Definition: Where there are multiple tortious factors which have caused the claimant’s loss, the courts will divide liability between the various defendants reflecting the respective fault of each defendant.
EXAMPLE:
- C crosses a road but is hit by Car A and, after being pushed further into the road, is hit by Car B.
- Both drivers were driving negligently.
- It was impossible to say which collision caused C’s injury.
Result: Each D was responsible for (25%) of C’s losses via apportionment.
(The remaining 50% was due to C’s own contributory negligence).
A claimant suffered a serious arm injury at work due to their employer’s negligence and was signed off work for four months. Two months after the accident at work, the claimant was diagnosed with arthritis in the same arm and had to stop working completely. The arthritis was entirely unconnected with the accident at work and/or the injury that resulted.
Question: When does the employer, if ever, stop being liable for the C’s injury?
Answer: The employer will be liable for the claimant’s losses up until the point that the arthritis developed.
Reasoning: The (Jobling) case tells us that under such circumstances the defendant is only liable up to the natural event.
Where C suffers harm from D’s negligence (e.g. wrist fracture), but then C suffers harm due to a natural event (e.g. cancer), when does the D - if at all - stop being liable for C’s injury?
The D is liable for C’s losses up to the point that C develops cancer.
Here we are dealing with a tort (D’s negligence) followed by a natural event (cancer) and Jobling tells us that under such circumstances the defendant is only liable up to the natural event.
Is mesothelioma cases, where multiple negligent employers caused C’s injury - are they all responsible for C’s harm in full?
What if only 1 of the 5 negligent employers can be found?
Yes, they are all liable in full - joint and severally liable.
What happens where C suffers harm from D1, and later that week, D2 also negligently harms C.
On the facts, C only suffered minor harm (e.g. requiring only a paint respray or minor fixes).
In this situation - is D2 liable to repay C any money?
In this case (Performance Cars v Abraham), D1’s harm already required the Claimant to re-spray his car’s paint. D2’s collision did not do any additional harm.
Therefore, D1 was liable for the whole amount; D2 did not have to pay anything.
