Question

Treatment with statins can reduce the risk of a major cardiovascular event in people with specified risk factors. During about 2 years of follow-up in the JUPITER trial, 142 of 8901 subjects treated with a statin had a major cardiovascular event. Controversy persists about whether statins reduce risk of cardiovascular events entirely through their effects on cholesterol levels or whether other pathways, such as reductions in inflammation, are also relevant. In JUPITER trial, statin therapy was associated with an average reduction of 1.2 mmol per liter in concentration of LDL (Low density lipoprotein) cholesterol. Based on average effects over multiple clinical trials, it is estimated that each 1 mmol per liter reduction in LDL cholesterol is associated with a 20% reduction in risk of major cardiovascular events. Hence, the expected event rate due to LDL reduction would be 0.028-0.2(0.028)(1.2)=0.0213

Assess whether the observed 2-year risk in the Jupiter study is consistent with this event rate at the 5% level. Hint: Use a confidence interval approach.

Answer 1