Last reviewed: 24 April 2026 by Editorial Team

Medical Negligence Glossary

Definitions of the legal and clinical terms used throughout this site. Each term links back from the relevant guides.

Bolam test

The standard for breach of duty: a clinician is not negligent if their conduct would be supported by a responsible body of practitioners in the same field (Bolam v Friern Hospital Management Committee 1957).

Bolitho qualification

Refines Bolam: the supportive body of opinion must itself withstand logical analysis (Bolitho v City and Hackney HA 1997).

Montgomery consent

The standard for informed consent: clinicians must disclose any material risk a reasonable patient would attach significance to (Montgomery v Lanarkshire Health Board 2015).

Breach of duty

Care that fell below the standard expected of a reasonably competent practitioner in the relevant specialty.

Causation

Proof that the breach of duty caused the harm — usually that 'but for' the negligence the harm would not have occurred, on the balance of probabilities.

Balance of probabilities

The civil standard of proof — more likely than not (over 50%). Lower than the criminal standard.

Limitation period

The deadline by which court proceedings must be issued. In England and Wales the period is three years from the negligent act or from the date of knowledge.

Date of knowledge

The date the claimant first knew, or could reasonably have known, that their injury was significant and attributable to the act complained of (Limitation Act 1980, s.14).

Section 33 discretion

The court's discretion under s.33 Limitation Act 1980 to disapply the three-year limit where it would be equitable to allow a claim to proceed out of time.

General damages

Compensation for non-financial loss — pain, suffering and loss of amenity — assessed by reference to the Judicial College Guidelines.

Special damages

Compensation for financial losses — past and future earnings, care, treatment, equipment, and accommodation costs.

Judicial College Guidelines (JCG)

The reference work used to assess general damages. The current edition is the 17th (April 2024).

Ogden Tables

Actuarial tables produced by the Government Actuary's Department used to capitalise future losses into a lump sum.

Personal injury discount rate (PIDR)

The assumed investment return applied to lump-sum awards for future losses, set under the Damages Act 1996. Currently +0.5% in England, Wales, Scotland and Northern Ireland.

Periodical Payments Order (PPO)

A court order providing index-linked annual payments instead of, or alongside, a lump sum — used in catastrophic injury cases.

Letter of Claim

The formal pre-action letter under the Pre-Action Protocol for the Resolution of Clinical Disputes setting out the allegations and claim.

Letter of Response

The defendant's response to the Letter of Claim, due within four months under the protocol.

Conditional Fee Agreement (CFA)

A 'no win, no fee' agreement: solicitor's fees are payable only on success, with a success fee taken from damages (capped for clinical negligence).

After the Event (ATE) insurance

Insurance taken out after an incident to cover the claimant's exposure to the defendant's costs and disbursements if the claim fails.

Qualified One-Way Costs Shifting (QOCS)

A rule protecting most personal injury and clinical negligence claimants from paying the defendant's costs if they lose, subject to exceptions.

NHS Resolution

The arms-length body that handles clinical negligence claims against NHS bodies in England under the Clinical Negligence Scheme for Trusts.

MNSI

Maternity and Newborn Safety Investigations programme, conducting independent investigations into qualifying maternity incidents.

Early Notification Scheme

NHS Resolution scheme requiring early reporting of severe brain injuries at birth to enable rapid investigation and family support.

Duty of candour

The statutory obligation on healthcare providers to be open and honest with patients when something goes wrong (Health and Social Care Act 2008 regulations).

Expert evidence

Independent opinion from a clinician of the same specialty as the defendant, addressing breach of duty, causation, and condition and prognosis.

Joint Settlement Meeting (JSM)

A without-prejudice meeting between the parties (usually with counsel) to negotiate settlement before trial.

Schedule of Loss

The detailed financial document setting out every head of past and future loss claimed by the claimant.