Although I appreciate the updated guidelines on the management of dyslipidemia developed by Jacques Genest and colleagues,1,2 I fear that family physicians will find it difficult to follow the recommendations because the requirements of individual patients are not well addressed.
In the guidelines, information about risk is not presented in a patient-friendly fashion. Patients (and their physicians) are often uncertain about the meaning of risks expressed as a percentage, and decisions about the correct course of action often depend on the way in which statistics are framed.3 For example, according to the model for estimating risk (presented in the appendix of the print summary1 and as Table 1 in the full guidelines2), a 75-year-old male nonsmoker with a systolic blood pressure of 145 mm Hg, a total cholesterol level of 5.4 mmol/L and a high-density lipoprotein cholesterol level of 1.1 mmol/L has a total of 15 risk points, representing a 10-year risk of a coronary event of 20%. On the basis of results from the Heart Protection Study, as summarized by Genest and colleagues,2 treatment with simvastatin should reduce that risk by 24%, to approximately 15%. A reduction in risk of nearly 25% sounds impressive, but an alternative way of presenting the same information would be to say that for every 100 patients taking simvastatin for 10 years, 95 would receive no benefit (80 would not have experienced an event even if untreated, and 15 would experience an event even though they were taking the medication).
Even more confusingly, the risk calculator1,2 will not show our hypothetical patient any evidence of benefit with simvastatin therapy: despite a probable reduction in cholesterol, this treatment will not change his total risk points, which will remain stubbornly at 15.
Dyslipidemia does not exist in isolation and is generally confounded by other cardiac hazards. I believe that the risk should have been presented in a pictorial fashion, expressing the relative importance of smoking cessation and reduction in blood pressure and cholesterol. The tables in the New Zealand4 and British5 guidelines seem much more usable tools than the arithmetic calculation suggested by Genest and colleagues.1,2
Hugh R. Hindle Family Physician Hinton, Alta.
Footnotes
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Competing interests: None declared.