As part of its case management function, the court has the power to limit the extent of expert evidence obtained or direct how expert evidence is to be given. This includes the power to direct that evidence on a particular issue be given by a single joint expert.

In appropriate cases, single joint expert evidence offers several advantages: it reduces delay and expert fees, limits the amount of live evidence given at trial and narrows the scope for the parties to introduce polarised expert opinion.  The court is more likely to order expert evidence by a single joint expert where the subject matter is capable of agreement. In such a case, the joint expert is unlikely to be required to give evidence at trial. As Lord Woolf, Lord Chief Justice, stated in MP v Mid Kent Area Healthcare NHS Trust [2002] 1 WLR 210: “The report prepared by the single expert should be the evidence in the case on the issues covered by that expert’s report. In the normal way, therefore, there should be no need for that report to be amplified or tested by cross-examination. If it needs amplification or if it should be subject to cross-examination, the court has discretion to allow that to happen. The court permits that to happen either prior to the hearing or at the hearing. But the assumption should be that the single joint expert’s report is the evidence. Any amplification or cross-examination should be restricted as far as possible.”

If instructed correctly and the expert engages fully with all parties, single joint expert evidence is an effective tool in the court’s case management toolkit. In the text that follows, I summarise key issues experts should consider if asked to act as a single joint expert in a medical negligence case.

1. Agreeing the terms of instruction: An initial approach from the instructing solicitor should make it clear whether the expert is to be instructed by one party or on a single joint basis. If the latter, the expert should seek clarification on who the parties are, obtain contact details for their representatives and ensure that all parties are copied into ongoing correspondence. Unless ordered otherwise by the court, the parties will be jointly responsible for the single joint expert’s fee, with each liable for an equal share.

2. Instructions: The letter of instruction should be signed by all parties. If only one party has signed a letter of instruction, the single joint expert should seek clarification from the other parties as to whether the instructions are agreed, or whether separate instructions will follow. The expert should not commence work on their report until receipt of all instructions.

3. Be clear about what is being asked: The importance of reading the letter of instruction and the questions posed by the parties cannot be stressed enough. Before putting pen to paper, a joint expert should ask themselves two key questions: Are the facts agreed by all parties? Is my opinion required on differing factual scenarios? The expert must have at the forefront of their mind the general proposition that the court determines matters of fact and the expert gives their opinion on issues within their expertise. If the facts remain in dispute, the expert should give their opinion in the alternative. For example: “If the court finds the facts were [ABC], then my opinion is [x]. If the court finds the facts were [DEF], then my opinion is [y].”

4. NHS/privately funded provision: A common issue asked of joint experts in respect of quantum is whether the NHS or local social services will meet the claimant’s future medical or social care needs. In such a situation, the expert should identify the claimant’s future needs flowing from the negligently caused injury, quantify those needs on a privately funded basis and defer to the court on whether NHS or other local services are capable of meeting those future needs.

5. Provide a clear summary of instructions received: To avoid confusion between the parties and to ensure the expert addresses all instructions provided, it is good practice to set out a clear summary of the instructions received at the outset of the expert’s report.

6. Seeking guidance from the court: There may be situations where the parties give conflicting instructions, and despite seeking clarification from them, the expert has been unable to resolve the conflict. In this situation, the expert is entitled to seek clarification from the court pursuant to Civil Procedure Rule 35.14. This provision permits an expert to file at court a written request for directions, to assist them in carrying out their function as an expert.

7. Practicalities: Specific considerations apply in respect of a single joint expert: 

   1. as a matter of course, all correspondence to and from a single joint expert should be copied to all parties,

   2. a single joint expert should not attend a conference with counsel without the written consent in advance of the other parties,

   3. a single joint expert’s report should be provided to all parties at the same time,

   4. a single joint expert may be asked Part 35 questions by one or more parties to the litigation. The expert is well advised to answer the questions in a timely manner and provide their Part 35 response to all parties at the same time. The party asking the Part 35 questions should bear 100% of the expert’s fee for responding to the questions.

8. Trial attendance: it is rare for a single joint expert to be required to attend a trial for the reasons given in the extract from Lord Woolf’s judgment in MP v Mid Kent Area Healthcare NHS Trust set out above. If a party obtains the court’s permission to call a single joint expert to give oral evidence at trial, it is good practice for that party to inform the joint expert about the issues they will be asked to cover.

It is possible for a party to obtain their own report from an expert in the same discipline as the single joint expert and receive the court’s permission to call that expert at trial. In that situation, it is likely the second expert and the joint single expert will be required to attend an experts’ discussion and prepare a joint statement before trial. After providing their report and responding to Part 35 questions, the single joint expert should seek clarification from all parties on whether they will be required to attend trial.

Challenges, from a solicitor’s perspective, when instructing a joint expert

An expert will have been chosen for joint instruction because of their expertise in the subject matter in issue. Upon instructing a joint expert my expectation is the expert will review their letter of instruction and the evidence carefully and provide an impartial opinion for the court. A particular difficulty with a joint expert is the tendency on the part of an expert to provide a partisan opinion depending upon their previous claimant/defendant split of instructions as a single expert. For example, an expert whose medico-legal experience predominantly consists of claimant instruction may address issues from a claimant perspective rather than providing an impartial opinion.

Examples of difficulties I have encountered with joint experts in recent times include:

1. A joint expert not answering all the questions set out by the parties in the letter of instruction. It is likely the instructing parties will have considered the questions to ask a joint expert in some detail. The letter of instruction will have been through a series of amendments back and forth between the solicitors representing the parties. Every question will be asked for a reason. A joint expert should answer all questions posed even if they consider them to be trivial or obvious.

2. The joint expert straying outside their area of expertise and offering an opinion that could cut across or undermine evidence already obtained by the parties. For example, commenting upon a pre-existing medical condition and giving a view on life expectancy. Unless specifically requested to comment on life expectancy it is likely the parties to a medical negligence claim will have their own evidence on such a pivotal issue. When faced with this situation, the joint expert should seek guidance from all instructing parties whether they are to comment on life expectancy or defer to other expertise.

3. A joint expert offering a partisan opinion on how a claimant’s future needs will be funded. This often arises when the expert is asked to comment on whether the claimant’s future needs can be adequately met by NHS services. It is tempting for an expert, although good intentioned, to answer this question based on their experience of the NHS Trust who employs them, or their experience of services in their geographical region. The provision of NHS services and budgetary constraints is an issue of fact for the court to determine. In this situation it is far better for the joint expert to identify the claimant’s needs and cost those needs on a privately funded basis (an expert issue) and defer to legal argument on whether those needs will be publicly funded (an issue of law and fact for the court to determine).

My advice to experts being approached to act on a single joint basis is as follows.  The expert should take time at the outset to clarify their instructions with all parties, identify whether key facts are disputed and be sure to copy all parties into their correspondence for the duration of their instruction. If the practicalities summarised above are followed, and the expert stays within their area of expertise and offers an impartial opinion to assist the court, joint instruction need not be daunting.