Unstable angina: enoxaparin was cost-effective.

Clinical bottom line (level 1b)

  1. In U.S. patients with unstable angina, enoxaparin was less expensive and more effective at decreasing death, MI and recurrent angina, than unfractionated heparin.
Mark et al: Circulation 1998; 97: 1702-1707
Expires March 2003

The study

Resource-based regression model
Setting: 176 centres, US, Canada, South America and Europe.

Data was taken from a randomised trial of patients with unstable angina or non Q-wave myocardial infarction who were given either low molecular weight heparin or unfractionated heparin.

  • Viewpoint: medical service
  • Benefit assessment: Death, myocardial infarction and recurrent angina at 30 days.
  • Resources and costs: Estimated medical costs from initial admission throughout 30 day follow-up were calculated. Hospital bills were collected for hospital costs. Physician fees came from the 1995 Medical Fee Schedule for : daily follow-up, cardiac catheterisation, coronary angioplasty and coronary bypass surgery. The cost of enoxaparin (low molecular weight heparin) was $0.38 per mg and with two daily doses of 1 mg/kg, the mean cost per day was $69 for US patients. In the US the mean duration of treatment was 2.25 days, and hence $155 overall. Heparin therapy involves the cost of the drug, rental cost of the infusion pump, cost of aPTT laboratory determinations and nursing and physician time. Only disposable supply costs, cost of the infusion pump rental and cost of aPTTs were used to calculate the daily cost.
  • Sensitivity analysis: Cost regression model was used to impute US costs for all non-US patients and compared medical costs for the overall study cohort by intention to treat. A boot strap analysis on cost was also carried out.

    • The evidence

    intervention cost
    heparin $14,357
    ( death, MI or recurrent angina 23.3% )
    enoxaparin $13, 185
    ( death, MI or recurrent angina 19.8% )

    Effect of sensitivity analysis: After bootstrapping, 94% of the 200 samples showed a cost advantage for enoxaparin.

    Comments

    1. Not enough data is given to estimate cost saving if no 'pump-rental' is included (the situation in UK hospitals).

    Citation

    1. Mark DB, Cowper PA, Berkowitz SD, et al: Economic assessment of low-molecular-weight heparin (enoxaparin) versus unfractionated heparin in acute coronary syndrome patients: Results from the ESSENCE randomized trial. Circulation 1998; 97: 1702-1707
    Contributor: Clare Wotton and Bob Phillips, January 2000
    Reviewer: William Rhoton

    Clinical Question.
    Patient unstable angina
    Intervention or Exposure low molecular weight heparin
    Comparison unfractionated heparin
    Outcome cost-effectiveness