Expert evidence and quantum issues in DVT claims

Case summary

In January 2005, the Deceased, a 40-year-old telephone engineer was admitted as an emergency to his local NHS Trust. He was complaining of abdominal pains which were radiating through to his back and had started coughing up blood. He was diagnosed with a suspected pulmonary embolism (PE) but differential diagnoses included hypertension and left-sided pneumothorax. The diagnosis of pulmonary embolus was confirmed on CT pulmonary angiogram and he was prescribed Warfarin for a period of three months. Approximately one week after he had been gradually weaned off Warfarin, he presented to the Trust with pain in his right calf. The ultrasound undertaken showed a distal deep vein thrombosis (DVT), i.e. a DVT isolated to the intramuscular veins in his calf. A D-Dimer test was also positive showing an elevated level of 858. He was advised to return in a week's time for a further scan. He duly re-attended one week later and underwent a second ultrasound which showed a continued DVT in the calf, but there was no proximal DVT, i.e. the DVT had not extended to above his knee. Since it had not extended to above his knee the treating doctors decided not to re-start him on anticoagulants and he was discharged.

By this point he had returned to normal work on light duties and it was anticipated that he would return to full duties very shortly. Recently married and planning to have a baby with his new wife, the Deceased had a strong and supportive family close to him. He was keen to progress his career and was undertaking a degree in business studies part-time, and was a valued employee. He did not drink or smoke and was a keen runner.

Eight days after the second appointment with his treating hospital he became seriously ill at home and suffered respiratory arrest. He was taken to hospital but attempts at resuscitation were unsuccessful and he was pronounced dead. The cause of death was a pulmonary embolism secondary to a DVT.

The Claim and the Defence

The Claimant argued that in light of the Deceased's previous history of a confirmed PE, when he re-presented with symptomatic DVT in June 2005 he was at a high risk of a developing a subsequent PE and should have been re-started on anticoagulants. The literature suggested that his history of a PE meant that he was at greater risk of developing a further PE in the future. The Claimant also argued that the risk of death from PE if he was not started on anticoagulants was so great as to outweigh any risks associated with taking anticoagulants, especially in light of his history of having taken them without incident over 3 months previously. It was accepted, however, that the risks increase with the length of time a patient takes anticoagulants, and age. However, no detailed discussion about the comparative risks involved in taking or not taking anticoagulants ever took place with the Deceased so that he could make an informed decision about his treatment options.

In defence it was argued that because distal DVTs are much less likely to propagate than proximal ones, it is reasonable to adopt a ‘wait and see’ approach with them and if there was no progression of the clot over the following week not to treat the DVT. Furthermore, the risks of not starting lifelong anticoagulants (i.e. suffering a PE and death) were outweighed by the risks associated with anticoagulants, such as haemorrhage. The Defendant relied on the 1998 British Society for Haematology guidelines which suggested that calf vein thrombi do not typically extend to cause PE. It also argued that the risk of developing a subsequent PE was very low and that very low risk was outweighed by the risks associated with the prescription of Warfarin or other anticoagulants, in particular the risk of major haemorrhage resulting in permanent disability or death. They also asserted the Deceased was properly counselled as to his treatment options and treatment was appropriate. They did not address our assertion that in the first instance and as a minimum the Deceased should have been re-started on anticoagulants for a period of 3–6 months.

In respect of quantum, the particular problem was that the Deceased at the time of his death was earning significantly less that his wife. At the time of his death she had taken a one-year fixed-term contract as a locum solicitor. However, the case of Higgs v Drinkwater sets a precedent that a widow's earning potential is set at the earnings she was receiving at the time of her husband's death and the court is unable to take into account a greater reliance due to the possibility of taking time off to bring up children (unless already pregnant at the time of death: see Wheatley v Cunningham). In this case the widow was offered a renewal of her contract following its completion but on a part-time basis only and has never returned to full-time work. Her earnings on a part-time basis were similar to the Deceased's pre-death earnings. Although she was made redundant at the peak of the recession, she subsequently obtained a new part-time legal position, earning a little less than she was before.

The Deceased worked for a large corporation with a final salary pension scheme. This meant that in addition to a dependency claim on loss of the Deceased's earnings, there was also a significant claim for loss dependency on the Deceased's pension. The Claimant did not have a final salary pension scheme and there was a novel point regarding the approach to the calculation of the pension loss dependency and whether any account should be taken of the projected value of her private pensions (which she had stopped contributing to after the Deceased's death).

Liability and causation – issues with expert evidence

Our first difficulty lay in identifying a suitable chest physician to report. The Deceased had been under the care of the team of a pre-eminent consultant chest physician and a recognized expert in DVT treatment (having been involved in the drafting of the British Thoracic Society Guidelines on the management of DVT). Because of the reputation of the team who treated the Deceased it was particularly difficult to find an authoritative expert who would be able to act who did not have experience in working with any member of that team or a personal friendship/relationship with them. We also needed an expert who was willing to criticize the care given by a national expert on the subject and stand up in court if so required. Rather than sending out bland letters of approach we contacted a known expert and asked him if he could report but highlighted the risk of conflict. The letter of approach was sufficiently detailed to ensure he would know immediately if there was any potential conflict. He confirmed there would be and personally recommended another expert. We took the same approach again with the second expert, making clear where the recommendation had come from.

The second difficulty then arose once we saw the defence. Up to that point the defence set out in the letter of response had not relied on any authorities and had been sparse in its response. It had not raised consent issues and there had been no mention of any haematological issues. The defence, however, set out a little more detail and raised the defence of risk–benefit analysis regarding taking anticoagulants and the interpretation and applicability of the British Haematological Guidelines to this case. However, it did not fully address our case on causation. Therefore, we had three issues to consider. First, as the defence did not fully address all the allegations in the particulars of clam we decided to make a detailed Part 18 request for further information. Second, we needed to analyse the guidelines and supporting academic studies to identify the extent to which the Defendant's case held up and to frame the request. Third, we had to consider whether the haematology issues raised by the reliance of the Defendant on British Haematology Guidelines mandated the instruction of a haematologist.

The request for further information was not initially answered, and we only obtained a response after an order to force compliance obtained following a CMC. When the response was received, the most frequently made comment was that it was inappropriate to respond in advance of exchange of expert evidence. However, we did not end up pursuing this further with them as an admission of breach of duty was made shortly afterwards. In order to frame our request and analyse the strength of the Defendant's case, we carried out a literature review with the assistance of our expert. This identified that the 1998 Guidelines relied on a paper by Cogo et al. ¹ for the proposition that it would be reasonable not to treat a distal DVT. However, that study expressly excluded patients who had a previous history of confirmed PE and we also identified a more recent paper of Hollerweger et al. ² that indicated that calf vein thrombi can and do often develop into PE. We, therefore, used the request to try and force the Defendant to reconsider its case as well as to obtain a clearer understanding of the expert advice they were most likely receiving.

We used a subsequent CMC to apply for leave to call a haematologist. The application was opposed. In preparing for the hearing Counsel prepared a case summary. We also obtained a short statement from our chest physician expert setting out the issues that were outside of his remit and that were for a haematology expert to address. The issues concentrated on the risk of significant injury, (particularly haemorrhage), from taking anticoagulants, how that risk would change over time and the interpretation and applicability of the British Haematological Guidelines to the facts of this case. We argued this was a Bolitho case inviting the court to consider the relative risks and benefits of the different types of treatment options and given that other expert disciplines deal with the management of DVT and prescription of the anticoagulants, there was clear overlap between disciplines. The risk of haemorrhage, heavily relied on by the Defendant, was also an issue outside of our chest physician's expertise. We were opposed on the basis that the claim arose out of the alleged negligence of chest physicians and only those chest physicians who specialize in treating DVTs on a daily basis are qualified to comment on the balancing of the risks of prescribing medication by chest physicians. The court gave permission for both parties to rely on a haematologist.

Shortly after this we received a full admission of liability. It emerged that the Defendant had relied on the evidence of the Defendant's medical team in preparing the defence and only once it had obtained independent expert evidence did it see some of the flaws of the defence. However, although there was a full admission, the Defendant went on to fight the issue of life expectancy. The experts focused on providing advice about the impact of taking long-term Warfarin on life expectancy, the impact of having had more than one DVT, and any risks that the Deceased may have had an underlying condition that predisposed to the clotting.

In considering life expectancy, Counsel was also aware of some general research on life expectancy in middle-class men who do not smoke or drink, living in the South East. Those studies indicated that healthy young individuals living in more affluent areas are likely to have an increased life expectancy. We put that research to the experts and they were able to comment authoritatively on the likelihood that the Deceased's lifestyle would have increased his life expectancy. Ultimately their conclusion was that the Deceased's life expectancy would have been very similar to the national average because although he lost 4 years by reason of his underlying disorder and the need to take long-term Warfarin, he gained a similar number of years due to his healthy, non-smoking lifestyle and supportive family.

Having considered evidence served by the Claimant, the Defendants advised that they would be relying on their own expert evidence which was served with the Counter-Schedule. The case then proceeded to a round-table meeting in the context of significant agreement between the experts about life-expectancy issues except for the question of the Deceased having gained years by virtue of his healthy lifestyle. However, broadly the experts were in agreement about the methods of calculation and epidemiology.

When we raised with the Defendant's Insurer, the NHSLA, why it had taken them so long to admit to this claim, they pointed out that they had been entitled to rely on the expert evidence of the treating doctors in this case who were pre-eminent in their field and that it was only as the case evolved that they were able to identify what their weaknesses might be and make an admission and that they made an admission at the earliest point they were able to do so. It is for a Defendant or Claimant to make the judgement call as to at what point independent expert evidence is obtained for their case, and this was always a difficult case to investigate for both sides. Nevertheless, it was a source of additional pain to our client that she began querying the treatment her husband received immediately after his death but it took over 4 years to have her concerns vindicated with the admission, and that she had to litigate to get that admission rather than through the complaints process.

Quantum

One further feature in this case was that we quantified on the basis of an Ogden VI approach. Unfortunately, the lower courts have repeatedly held that they are bound by the decision in Cookson v Knowles [1979] AC 556 to calculate multipliers for future loss as at the date of death: Wilkins v William Press (30 November 2000, QBD, unreported); White v ESAB [2002] PIQR Q76; ATH & anor v MS [2002] EWCA Civ 792 and A Train & Sons Ltd v Fletcher [2008] 4 All ER 699. However, a number of leading commentators including the editors of McGregor on Damages (18th edition) have criticized the conventional method of assessment. The Law Commission in their Paper No 263 entitled ‘Claims for Wrongful Death’, published in November 1999, recommended that the law in this area should be reformed. Criticisms of the traditional approach include:

The traditional approach is too complicated and a simpler method is needed;

In the most recent case of A Train & Sons Ltd v Fletcher [2008] 4 All ER 699 Sir Mark Potter described the Ogden approach as ‘an attractive solution’. He went on to say that the time was ripe for a reconsideration of the position.

We decided that if we fought on that point, which we could not win at first instance or in the Court of Appeal given the binding decision of Cookson v Knowles on all lower courts, we would seek permission for a leapfrog appeal to the Supreme Court on this issue (assuming the Defendant consented to such an appeal). The Defendant did not accept our approach, unsurprisingly, and it was the subject of some discussion at the round-table settlement meeting. At no point did the Defendant accept that Ogden VI should apply but nevertheless we obtained a settlement for the Claimant at £360,000.

The following issues arose in assessing quantum:

The pleaded value of the claim in the updated schedule of loss was £415,628 using the Cookson v Knowles approach and £456,093 using an Ogden VI approach. However, there were a number of quantum issues which needed to be determined by the court and we were unlikely to win on all issues. In particular, as the Claimant was working full-time at the time of death but was now only working part-time and we had only given credit in the future for part-time earnings up to a retirement age of 55 years. It was, therefore, difficult to predict the outcome with precise accuracy but on our calculations the best the Claimant would do on a conventional Cookson v Knowles approach if everything went our way at trial was an award in the region of £350,000;

Final words

Many claims arise out of failure to diagnose or failure to treat or both. In this case there was no doubt about the diagnosis, it was made correctly and there was no delay. Further, the Defendant received treatment and the Defendant doctor had ‘written the book’ on the diagnosis and treatment of the condition. This case illustrates how it is possible to still challenge accepted thinking even by nationally recognized experts and win.

If you get a difficult case, arguing that a condition should be treated differently and that different treatment would have altered the outcome, make sure you get an expert you can work with who you trust. It was essential that before he accepted instructions that our expert understood the additional issues involved and was prepared to challenge a respected colleague. The expert we chose had the experience in dealing with medicolegal work but was also well-respected among his peers. It was also our expert's recognition of where issues were outside his experience and willingness to commit this to paper that helped the application for a second expert to succeed.

Don't be afraid to trawl through the academic references, and what you don't understand check with your experts. If they can't explain it to you then they will be unable to explain it to a trial judge. Likewise if your experts may have missed points, such as reasons why a person's life expectancy might have been more than the average to start with, do take this up with them and give them the chance to consider any supporting literature.

On assessing quantum never assume the obvious. Although the Claimant was earning more than the Deceased at the time of his death, she was still entitled to a significant dependency award. In particular, it is worthwhile looking carefully at pension loss, which added a significant amount to the value of this claim. Further, while the present case law is to the effect that all lower courts are bound to calculate multipliers as at date of death, this is inherently unfair to Claimants. There appears to be some momentum for change and members of the judiciary who have considered the issue have been attracted to the modern calculation of loss using multipliers assessed as at the date of trial bringing the assessment of fatal accident act claims into line with ordinary personal injury and clinical negligence claims as proposed by the Ogden Working Party. These issues should be discussed carefully with the Claimant and if he or she is willing to fight the issue or at least hold out until nearer trial, a better result may be achieved. Our understanding is that the appeals in White v ESAB and A Train were both settled on favourable terms for the Claimant and it is not hard to see why as Defendants are no doubt keen to keep the status quo and prevent their Lordships from getting an opportunity to revisit Cookson v Knowles.