Drug maker’s PR firm is force behind blood clot awareness campaignBMJ 2008; 336 doi: https://doi.org/10.1136/bmj.a502 (Published 26 June 2008) Cite this as: BMJ 2008;336:1460
All rapid responses
We read with interest the article by Ray Moynihan.[1 ]We do not
support the “routine” use of thromboprophylaxis in hospitalized medical
patients. The justification of the impact of thromboprophylaxis on
mortality and cost benefit in Australia were questioned.
There seems to be a similar support for thromboprophylaxis for
hospitalized medical patients in the UK as well, which we think lacks a
robust evidence base. We read with interest the guidance from the
department of health (DoH) on the prevention of venous thrombo-embolism
(VTE) in hospitalized patients and their subsequent guidance on risk
assessment. The role for thromboprophylaxis in surgical patients is
very well established and with an excellent evidence base. However we fail
to understand the DoH’s enthusiasm for thromboprophylaxis in virtually all
patients hospitalized with a “medical” complaint.
The DoH guidance states that “VTE caused in excess of 25,000
potentially preventable deaths per annum in UK”, which would be a very
compelling argument for thromboprophylaxis in medical patients provided,
as in surgical patients, it resulted in decrease in mortality. However
this is not the case. None of the randomized controlled trials looking at
thromboprophylaxis in medical patients have shown significant reduction in
mortality. An adequately powered, prospective, randomized, double blind
study looking specifically at mortality failed to show a reduction.
There are several recent meta-analyses on the role of thromboprophylaxis
in medical patients and they all failed to show a reduction in overall
mortality.[6,7,8] In fact the meta-analysis even casts doubt as to the
efficacy of thromboprophylaxis in preventing soft end points such as
symptomatic VTE, both DVT and PE.
In medical patients what is needed is an appropriate risk assessment
tool, which we do not think the recent DoH guidance provides. For example
an age of >60 years alone without any other risk factor lacks robust
evidence as a recommendation. Similarly the presence of a chronic disease
or a BMI >30kg/m2 are by themselves not very persuasive indications for
thromboprophylaxis. Under the guidance the vast majority of medical
inpatients are likely to meet at least one of the “high thrombosis risk”
factors and merit thromboprophylaxis. In fact multiple risk factors were
needed for inclusion in all the recent large medical thromboprophylaxis
studies.[9,10,11] There are medical, nursing and patient costs which need
to be considered. Bruising and pain at injection sites are not uncommon.
Clinically significant bleeding and heparin induced thrombocytopenia can
be life threatening.
Thromboprophylaxis in some hospitalized medical patients maybe
justified but the broad brush recommended by the DoH is not supported by
the data. There is an urgent need to develop a validated risk
stratification model to identify those patients who may benefit.
1. Moynihan R. Drug maker's PR firm is force behind blood clot
awareness campaign. BMJ. 2008 Jun 28;336(7659):1460-1.
2. Cole RD. DVT prophylaxis will prevent 5000 Australians from dieing
of PE. Really? (Rapid response to : Moynihan R. Drug maker's PR firm is
force behind blood clot awareness campaign. BMJ. 2008 Jun
5. Mahé I, Bergmann JF, d'Azémar P, Vaissie JJ, Caulin C. Lack of
effect of a low-molecular-weight heparin (nadroparin) on mortality in
bedridden medical in-patients: a prospective randomised double-blind
study. Eur J Clin Pharmacol. 2005;61(5-6):347-51.
6. Själander A, Jansson JH, Bergqvist D, Eriksson H, Carlberg B,
Svensson P. Efficacy and safety of anticoagulant prophylaxis to prevent
venous thromboembolism in acutely ill medical inpatients: a meta-analysis.
J Intern Med. 2008;263(1):52-60.
7. Kanaan AO, Silva MA, Donovan JL, Roy T, Al-Homsi AS. Meta-
analysis of venous thromboembolism prophylaxis in medically Ill patients.
Clin Ther. 2007;29(11):2395-405.
8. Dentali F, Douketis JD, Gianni M, Lim W, Crowther MA. Meta-
analysis: anticoagulant prophylaxis to prevent symptomatic venous
thromboembolism in hospitalized medical patients. Ann Intern Med.
9. Cohen AT, Davidson BL, Gallus AS, Lassen MR, Prins MH, Tomkowski
W, Turpie AG, Egberts JF, Lensing AW; ARTEMIS Investigators. Efficacy and
safety of fondaparinux for the prevention of venous thromboembolism in
older acute medical patients: randomised placebo controlled trial. BMJ.
10. Leizorovicz A, Cohen AT, Turpie AG, Olsson CG, Vaitkus PT,
Goldhaber SZ; PREVENT Medical Thromboprophylaxis Study Group. Randomized,
placebo-controlled trial of dalteparin for the prevention of venous
thromboembolism in acutely ill medical patients. Circulation.
11. Samama MM, Cohen AT, Darmon JY, Desjardins L, Eldor A, Janbon C,
Leizorovicz A, Nguyen H, Olsson CG, Turpie AG, Weisslinger N. A comparison
of enoxaparin with placebo for the prevention of venous thromboembolism in
acutely ill medical patients. Prophylaxis in Medical Patients with
Enoxaparin Study Group. N Engl J Med. 1999;341(11):793-800.
Competing interests: No competing interests
Where did the figure of 5000 preventable deaths per year from venous
thromboembolism in Australia come from? It is commonly estimated that 1-2%
of pulmonary embolism cases proves fatal. This implies that there are
250,000 - 500,000 cases of preventable pulmonary embolism occuring per
year in Australia, which has a total population of 20 million. And where
did the cost benefit analysis come from? Was it an independent analysis
looking at clinically significant proven preventable end-points (mortality
and morbidity)? Or rather industry sponsored extrapolation of industry
sponsored trials involving surrogate endpoints of uncertain significance?
Dare I suggest this is industry created paranoia of epidemic proportion?
Competing interests: No competing interests