Doctors' perceptions of the prognostic benefit of statins in patients who have had myocardial infarction

Background: We wished to assess how General Practitioners (GPs) and cardiologists perceive and communicate the benefits of therapy with statins (hydroxymethylglutaryl-coenzyme A reductase inhibitors) in a patient following myocardial infarction.
Methods: We interviewed 20 GPs and 22 cardiologists to determine treatment policy and ways of expressing its benefits to a patient after myocardial infarction with moderate dyslipidaemia. We asked what drug and dosage they would recommend and how they would express potential benefits of therapy, given a range of options including reduced relative and absolute risk of events.
Results: Most GPs would start a low dose (10–20 mg/day) of simvastatin (the only freely prescribable funded statin in New Zealand) whereas cardiologists would commence 40 mg/day immediately ( P  = 0.001). All but one cardiologist would justify therapy to the patient by citing a reduced chance of a major adverse cardiovascular event. Nine GPs and one cardiologist estimated a gain of more than 5 years of life from statin therapy. Cardiologists were more optimistic than GPs about relative risk reduction ( P  = 0.04). Only 50% of GPs and 68% of cardiologists were able to estimate an absolute risk reduction over 5 years, such estimates varying widely with no significant difference in responses between the groups ( P  = 0.2). No doctors felt comfortable using number needed to treat or odds ratio.
Conclusion: There were substantial differences between the two groups of clinicians in perception and policy of statin therapy, frequent overestimation of treatment benefits and a reluctance to impart numerical estimates of benefit to patients.