Letters

Optimal age for starting lipid lowering treatment

BMJ 2000; 321 doi: https://doi.org/10.1136/bmj.321.7261.637 (Published 09 September 2000) Cite this as: BMJ 2000;321:637

A 10 year risk of 30% should be used

  1. William G Simpson, consultant in clinical biochemistry ([email protected]),
  2. Patrick Twomey, specialist registrar in clinical biochemistry
  1. Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZD
  2. Edinburgh Royal Infirmary, Edinburgh EH3 9YW
  3. Department of Public Health and Epidemiology, University of Birmingham, Birmingham B15 2TT
  4. Section of Clinical Pharmacology and Therapeutics, Division of Clinical Sciences (CSUH Trust), Royal Hallamshire Hospital, Sheffield S10 2JF
  5. Centre for Clinical Pharmacology and Therapeutics, University College London, London WC1E 6JJ

    EDITOR—Ulrich et al have bravely attempted to tackle a problem that has been quietly sidestepped for some time—namely, that lipid lowering does not (as far as we are aware) prevent coronary heart disease, it merely postpones it.1 The concept of assessing treatment in terms of “event free life years gained” is a useful one, but using a risk calculator to estimate potential benefit is fraught with difficulty.

    The authors base their calculation on the Framingham equation, in common with most coronary risk calculators, and have made one particularly common but incorrect assumption regarding age. With the publication of the Framingham equation, Anderson et al stated that the equation “may be used for estimating outcome probabilities over a range of 4 to 12 years for persons aged 30 to 74 years.”2 Quoting calculated risks for ages 15 to 94 is therefore inappropriate. To attempt to recalculate such risks using a pharmacologically lowered cholesterol concentration is even less appropriate.

    Anderson's statement is also relevant to the notion of a “3% annual risk,” which cannot be reliably predicted by the Framingham equation directly. The joint British guidelines circumvent this by referring to a “30% 10 year risk,” which will in fact identify subjects whose initial risk is less than 3% per year because the risk is higher in the later years.3

    Finally, it should be remembered that the Framingham equation is less reliable at the extremes of any of the variables included; hence a very high cholesterol concentration in a young person should stimulate further clinical thought. Ulrich et al calculated the benefits of treatment for cholesterol concentrations of 9 mmol/l and higher. People with these concentrations require proper investigation of their dyslipidaemia rather than a keyboard exercise to estimate (badly) cardiovascular risk.

    Footnotes

    • Competing interests None declared.

    References

    1. 1.
    2. 2.
    3. 3.

    It is more efficient to screen and treat elderly people

    1. Tom Marshall, lecturer in public health medicine
    1. Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZD
    2. Edinburgh Royal Infirmary, Edinburgh EH3 9YW
    3. Department of Public Health and Epidemiology, University of Birmingham, Birmingham B15 2TT
    4. Section of Clinical Pharmacology and Therapeutics, Division of Clinical Sciences (CSUH Trust), Royal Hallamshire Hospital, Sheffield S10 2JF
    5. Centre for Clinical Pharmacology and Therapeutics, University College London, London WC1E 6JJ

      EDITOR—Ulrich et al …

      View Full Text

      Sign in

      Log in through your institution

      Free trial

      Register for a free trial to thebmj.com to receive unlimited access to all content on thebmj.com for 14 days.
      Sign up for a free trial

      Subscribe