Hayden v Maidstone & Tunbridge Wells NHS Trust

In an acceleration case, the court must distinguish between establishing the cause of an actual past injury and estimating what would probably have happened in a hypothetical future. Past facts are determined on the balance of probabilities. Future or hypothetical events are assessed by estimating the relevant chances and reflecting them in the damages.

Where the evidence supports acceleration but does not establish an exact date, the court may make a reasoned estimate in years. It must base that estimate on the evidence, including the nature of the injury, the forces involved, pre-existing vulnerability and the claimant’s likely lifestyle, rather than relying on bare common sense or unsupported speculation.

The claimant, employed as a cardiac physiologist, suffered a cervical disc prolapse while assisting with the transfer of a patient at work. The defendant had admitted liability and causation of the accident. The issues were the extent to which the disc injury would have occurred in any event, the appropriate period of acceleration, the claimant’s continuing symptoms and the resulting assessment of damages.

The parties advanced substantially different valuations. The court therefore had to determine both the hypothetical timing of any uninjured prolapse and the claimant’s actual residual disability, earning capacity and care needs.

1. Liability and factual mechanism. The defendant’s admission established that the breach caused actionable loss and damage. Although the pleaded case did not expressly set out every aspect of the accident mechanism, the claimant had not been taken by surprise. The court found that the claimant’s arms were outstretched, her neck was extended and rotated, and that the manoeuvre included an upward element rather than a purely horizontal drag.
2. Acceleration methodology. The distinction between past facts and future or hypothetical events was essential. The actual accident and its causal connection with the prolapse were matters of fact. The question whether the disc would have prolapsed later was a question of chance. Following the approach identified in Davies v Taylor [1974] AC 207 and Mallett v McMonagle [1970] AC 166, the court was required to estimate the chances rather than apply an all-or-nothing balance-of-probabilities analysis.
3. The court rejected the defendant’s contention that the disc was primed to fail within 12 months. It also rejected the claimant’s proposed 49.5 per cent lifetime-risk calculation as insufficiently supported. The evidence nevertheless permitted a reasoned estimate. The disc had some pre-existing degeneration; the accident involved significant, though unquantified, forces; and the risk of later prolapse would have increased with age, degeneration and ordinary activity.
4. The court concluded that the appropriate acceleration period was 17½ years, representing the midpoint of a reasonable 15–20 year period. It rejected the suggestion that the evidential difficulties required full recovery, because the defendant had adduced a prima facie case and the evidence permitted a rational assessment.
5. The claimant was not found to have deliberately exaggerated her condition, although there was some mismatch between objective functioning and subjective symptoms. Her continuing right-arm radicular pain materially restricted heavy lifting, gardening and physiotherapy work. She remained fit for suitable part-time work, with some prospect of further improvement.
6. Judgment was entered for the claimant in the sum of £425,515.81, with provision for payment of the balance after interim payments, costs and detailed assessment as set out in the order.