Preventive health is a broad umbrella that includes such disparate services as vaccines for schoolchildren, blood pressure screenings, ad campaigns to discourage binge drinking, and special taxes on tobacco products. What all these programs have in common is an intention to spend money now in order to save money later—catching costly health problems before they arise or when they are less advanced and easier to treat.
However, even the most straightforward early interventions do not always save money over the long term. Something as seemingly basic as a cancer screening, if it is not narrowly targeted at high-risk patients, can fail to save money. In some cases, it can even do more harm than good. Trying to tell whether a preventive health program will be as effective—and cost-effective—as its proponents claim is a difficult task for policymakers and voters.