Letters
Cardiovascular diseases
Volume 200 - Issue 3

Primary prevention of cardiovascular disease: new guidelines, technologies and therapies

Authors:  Mark R Nelson and Jennifer A Doust

Med J Aust 2014; 200 (3): 148. || doi: 10.5694/mja13.11045
Published online: 17 February 2014
Does a formulaic approach based on traditional risk factors measure up?
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In reply: We thank Campbell and Aroney for their comments. Addressing Campbell’s concerns, risk categorisations are made to simplify stratification and communication of cardiovascular disease (CVD) risk. It is correct that the United States and Europe have a longer period and differing thresholds for action. A shorter period was selected in Australia due to patient preference for shorter-term over longer-term outcomes (ie, discounting).1 Categorisation arguments can similarly be made for the thresholds used for individual risk factors. The short-term approach can be thought of as best identifying those likely to have covert disease and to benefit from pharmacotherapy. The lifetime risk does not need to be ignored, as lifestyle interventions should still be recommended to reduce risk. The validation study cited by Campbell reports a c-statistic of 0.76 (95% CI, 0.71–0.81) — considerably better than a coin toss.2 “Simply repeating blood pressure and lipid level measurements” did not significantly alter this figure. Numerals entered in a risk calculator have the same standards for measurement as for individual risk factors. Reclassification is less likely for an absolute risk approach than an individual risk factor approach, as it is tempered by other measures.

Aroney is correct that traditional risk factors do not perfectly predict CVD events. However, management of traditional risk factors has contributed to the remarkable decline in CVD deaths in Australia since the late 1960s.3 The National Vascular Disease Prevention Alliance (NVDPA) has endorsed using absolute risk to identify who should receive pharmacotherapy,1 an approach supported in the study Aroney cites.4 Aroney suggests that computed tomography coronary calcium scoring should be used in place of or in addition to traditional risk factors to select patients for lipid-lowering therapy. There are conflicting recommendations on whether or not this approach is reasonable.5,6 In the Australian context, it is the Medical Services Advisory Committee that would consider the effectiveness and cost-effectiveness of this approach.

Authors

  • Mark R Nelson1
  • Jennifer A Doust2
  • 1. Discipline of General Practice, University of Tasmania, Hobart, TAS.
  • 2. Centre for Research in Evidence-Based Practice, Bond University, Gold Coast, QLD.

Correspondence: Mark.Nelson@utas.edu.au

Competing interests

Mark Nelson is a member of the NVDPA, which produced the absolute CVD risk assessment and management guidelines. Jennifer Doust is a member of the Pharmaceutical Benefits Advisory Committee, which produced the statin prescribing criteria.

References

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