Carter v Basildon & Thurrock University Hospitals NHS Foundation Trust

In a clinical negligence claim, causation is determined on the civil balance of probabilities, not by requiring medical evidence to reach the 95% confidence level used in scientific research. Statistical evidence is relevant but forms only part of the assessment. The court must evaluate the individual patient’s condition, prognosis, timing of the negligent omission and the likely effect of the treatment that should have been provided.

Where recognised first-line treatment would probably have been effective before a serious deterioration, and the claimant’s clinical features do not place the patient in an exceptionally adverse category, causation may be established even though treatment efficacy has not been statistically proved to the 95% confidence level.

Elaine Carter died after developing cerebral venous sinus thrombosis shortly after childbirth. The defendant hospital admitted that she had received negligent treatment on 6 October 2002 and should have been admitted for further assessment and observation.

The parties agreed that, following admission, a competent neurologist would have included cerebral venous sinus thrombosis in the differential diagnosis, arranged an urgent CT scan and administered Heparin at about 13.00 on 7 October, with supportive treatment as required. The central issue was whether that treatment would probably have prevented the subsequent deep cerebral venous occlusion and death. The defendant also sought, at a late stage, to argue that Mrs Carter would have survived with substantial disability, but that alternative case was not permitted.

1. Claim succeeded on causation. The admitted breach meant that Mrs Carter should have been admitted on 6 October. On the agreed evidence, she would probably have undergone urgent investigation and received Heparin from about 13.00 on 7 October.
2. The court found that her CVST had progressed relatively rapidly, but not exceptionally rapidly. By the time treatment should have begun, she did not display the adverse prognostic features usually associated with patients inevitably destined to die. Her age, sex, fitness, puerperal context and clinical presentation indicated a good prospect of survival.
3. The court accepted that Heparin acts quickly by arresting the formation of new thrombus, although it does not dissolve existing thrombus. Mrs Carter was deprived of this recognised first-line therapy for approximately five to six hours before the marked deterioration and deep venous occlusion.
4. Although controlled trials and the relevant literature had not established Heparin’s efficacy to the 95% confidence level, that was not the civil standard of proof. The evidence showed a consistent and clinically meaningful trend in favour of anticoagulation. The court was entitled to infer, on the balance of probabilities, that timely Heparin would have prevented the fatal progression.
5. The statistical trend towards survival, referred to with [2005] 2 AC 176, was relevant but not determinative. [2002] EWCA Civ 1406 was distinguishable because the evidential position there did not permit the court to conclude, even on the balance of probabilities, that the alternative treatment would have altered the outcome. The 95% confidence level discussed in [1990] 1 Med LR 117 and that decision was not required in this case.
6. The claim therefore succeeded on causation. The issue of damages was adjourned for further argument if the parties could not agree quantum.

First-instance judgment. No earlier appellate decision is stated in the judgment.