Letter to the Editor
Editor, -The article by Hill and Smith (Aust Prescr 2005;28:34-7) states that when the blood pressure, on at least three separate occasions, exceeds the threshold pressures which predict an increased cardiovascular risk, treatment is required. They quote systolic and diastolic figures for triggering treatment, but then state that the patient's predicted cardiovascular risk should determine the time for intervention.
When does cardiovascular risk become 'increased'? Over what acceptable level? How is the 'predicted cardiovascular risk' used to delay the time for active intervention when one of the measurements has crossed the red line?
Why is there no reference in the entire article to discussion with the patient of their acceptable risk levels? The New Zealand Cardiovascular Risk Calculator to which they refer us has numbers needed to treat ranging from <10 to >120. The result of treatment is prevention of one cardiovascular event in five years.
This would suggest that even in a high risk 'herd' of patients, drenching all of them delivers benefits to very few. When the 'herd' consists of autonomous fellow human beings, should they not be involved in the good shepherd's calculations?
- The New Zealand Cardiovascular Risk Calculator. In:The assessment and management of cardiovascular risk. Best practice evidence-based guideline. Wellington, NZ: New Zealand Guidelines Group (NZGG); 2003. p. xxii. [cited 2005 Aug 22].
- Bogaty P, Brophy J. Numbers needed to treat (needlessly?). Lancet 2005;365:1307-8.