Under-utilisation of beta-blockers after acute myocardial infarction. Pharmacoeconomic implications.

We reviewed the literature on the efficacy and effectiveness of beta-blocker therapy and examined the economic consequences of under-utilisation. Despite the literature documenting the value of beta-blockers, the therapy is not prescribed at the appropriate rates. Approximately half of acute myocardial infarction (AMI) survivors who are eligible for the therapy do not receive it. There are 3 sources of costs that may arise from such under-utilisation: (i) increased morbidity and mortality associated with under-use; (ii) increased demand for related medical resources when the health state following an AMI is suboptimal due to under-use of beta-blocker therapy; and (iii) increased cost due to substitution of higher cost and/or less effective treatments for beta-blockers. For the first category, there is evidence suggesting that around 2900 to 5000 lives are lost in the US in the first year following an AMI due to underprescription. There is very little evidence on the second category of costs; 1 recent study does address this issue and indicates that beta-blocker therapy can lead to a 22% relative risk reduction for hospital readmission during the first year. Several studies also show a decrease in reinfarction. There is no information that addresses the third category of costs adequately (though 1 study does present evidence of substitution of calcium channel-blockers for beta-blockers). We conclude that there is a dearth of evidence on the economic consequences of the under-utilisation of beta-blocker therapy. What does exist suggests that the net costs to society may be substantial.