Apples and oranges

Dear Editor

Mansi, Sumithran and Kinaan appropriately advocate for shared decision-making when considering statins for secondary prevention of CVD. But their article doesn’t furnish the information that would allow patients and clinicians to balance the risks and benefits of using a statin. The benefit of avoiding a cardiovascular event (a relatively discrete outcome with appreciable symptoms, disability and risk of death) is compared to the disbenefit of developing type 2 diabetes (passing a particular level of a continuous biochemical variable, with a low likelihood of directly-related symptoms). What we need to compare is the risk of experiencing patient-relevant outcomes (such as reduced exercise tolerance, need for dialysis, amputation, subsequent treatment burden, death) with a statin or without, regardless of the ultimate cause.

Without this information, shared decisions which take account of the small risk of statin-induced diabetes are unlikely to be any better-informed. Still less would patients and clinicians be able to interpret and rationally act on the results of blood glucose or Hba_1c measurements done to ‘monitor’ the effects of starting a statin.