Each incremental advance in medical therapy is tempered by the knowledge that many patients will not receive recommended treatments and therefore will not benefit from them. However, improving health care delivery has taken a back seat to investing in new drugs. On a governmental level, the Agency for Healthcare Research and Quality has an annual budget of $300 million, an amount that is equal to about 1 percent of the National Institutes of Health’s $29 billion budget and the $32 billion pharmaceutical companies spend annually on drug development. Woolf and Johnson define fidelity as, “the extent to which the system provides patients the precise interventions they need, delivered properly, precisely when they need them.” They use this concept to illustrate a “break-even point” at which as many lives are saved by creating a new drug as by maximizing the delivery of established drugs. They examine the balance between improving drug effectiveness and fidelity in two common clinical scenarios: antiplatelet agents for stroke and statins for coronary artery disease (CAD).

Clinical trials have established that daily aspirin reduces the rate of recurrent stroke by 23 percent. In a population of 100,000 affected patients, all taking aspirin, 23,000 strokes would be prevented. However, only about 58 percent of eligible patients receive aspirin, which would account for only 13,340 prevented strokes. To prevent the same number of strokes that are associated with aspirin (the break-even point), a new antiplatelet drug would need to be 74 percent more effective at preventing strokes than aspirin. Instead, clopidogrel (Plavix) and ticlopidine (Ticlid) are estimated to be only 10 to 12 percent more effective.

Simvastatin (Zocor) and pravastatin (Pravachol) reduce five-year mortality from CAD by 24 percent. In a population of 100,000 affected patients all taking one of these drugs, 24,000 deaths could be prevented. However, only 33 percent of eligible patients receive these cholesterol-lowering drugs. To reach the break-even point, a new drug would need to reduce CAD-associated mortality by at least 72 percent. In other words, it would need to be three times as effective as simvastatin or pravastatin. The new drug rosuvastatin (Crestor), for which mortality data are lacking, is 26 percent more effective than the maximal dose of pravastatin.

The authors acknowledge that no systems improvement is likely to approach, much less achieve, 100 percent fidelity. They also concede that marketing campaigns for new drugs often improve delivery of care by drawing physicians’ attention to disease guidelines. On the other hand, reminder systems improve compliance with guidelines more successfully and at significantly less expense. The authors conclude that investments in improving fidelity of care are likely to produce greater public health benefits than equivalent investments in new drug development.