Misdiagnosis and Delayed Diagnosis Claims

When a Misdiagnosis Is Negligent

Direct Answer: A diagnosis is negligent only if no reasonable doctor of that specialty, acting with proper skill, would have reached it, or if they failed to take steps such as ordering tests or referring that a competent doctor would have taken.

Many conditions have overlapping or non-specific symptoms, so doctors are judged on the information they had at the time, not with hindsight. The strongest claims involve red-flag symptoms that were ignored, abnormal test results that were not followed up, scans that were misreported, or a failure to refer to a specialist.

Courts apply the Bolam and Bolitho tests: the treatment or advice must be one that a responsible body of medical opinion would support, and that opinion must withstand logical analysis. This is why an independent expert's report on the standard of care is central.

Causation and the Loss of Chance Problem

You must show, on the balance of probabilities, that with proper care your outcome would have been better. In Gregg v Scott [2005] UKHL 2 the House of Lords held that a claimant cannot recover for a reduced chance of a better outcome where that chance was below 50%, so a delay that only marginally worsened your prospects may not be compensable.

In practice the question is often what would have happened if the diagnosis had been made earlier: would the condition have been treatable, would surgery have been avoided, would the disability have been smaller? Experts give evidence on the timeline.

Time Limits and Costs

The three-year limit can run from your date of knowledge, which is important in delayed diagnosis because you may only learn of the earlier error when the correct diagnosis is made. Do not delay, though, because evidence and memories fade and a court's discretion to extend time is not guaranteed.