Last week's media reports of a proposed deep vein thrombosis (DVT) class action threaten yet another blow to the already beleaguered insurance and airline industries.

However, for the claimants to succeed they must prove, among other things, that flying caused their DVT. Of the millions of passengers who take to the air each year, only a few develop DVT.

Couple this with the inconclusive medical research into the causes of DVT, plus the acknowledged natural occurrence of the condition within the general population, and you begin to see the challenge facing the proposed claimants.

Nonetheless, airlines and their insurers who are looking at future risk management, should note the recommendations of the House of Lords select committee report (November 2000) on air travel and health. Some airlines already provide advance information on DVT and in-flight videos that actively encourage leg exercises during the flight.

But how far must airlines go? Travellers would welcome more seat space and legroom, but not increased costs. Statistically, a proportion of DVT sufferers travelled first or business class - "economy class syndrome" is a misnomer.

Encouraged mobility may be ideal, but, during in-flight turbulence, safety demands passengers remain seated. There is also a suggested link to drinking - although it is unlikely travellers would appreciate a policy of alcohol-free flights. Should airlines refuse to carry individuals thought to be at increased risk of DVT, such as those over 40 or those taking the contraceptive pill?

Finally, a thought for employers' liability insurers. Air travel is often an essential component of employment but could it be argued that employers breach health and safety duties by allowing employees to fly with an airline which has not complied with the recommendations?

  • Clare Hirst is a partner with insurance specialist law firm Davies Lavery