Do These Health-Care Companies Pass Buffett's Test?

We'd all like to invest as successfully as the legendary Warren Buffett. He calculates return on invested capital to help determine whether a company has an economic moat -- the ability to earn returns on its money beyond that money's cost.

ROIC is perhaps the most important metric in value investing. By determining a company's ROIC, you can see how well it's using the cash you entrust to it, and whether it's actually creating value for you. Simply put, ROIC divides a company's operating profit by the amount of investment it took to get that profit:

ROIC = Net operating profit after taxes / Invested capital

This one-size-fits-all calculation cuts out many of the legal accounting tricks (such as excessive debt) that managers use to boost earnings numbers, and provides you with an apples-to-apples way to evaluate businesses, even across industries. The higher the ROIC, the more efficiently the company uses capital.

Ultimately, we're looking for companies that can invest their money at rates that are higher than the cost of capital, which for most businesses lands between 8% and 12%. Ideally, we want to see ROIC greater than 12%, at minimum. We're also seeking a history of increasing returns, or at least steady returns, which indicate that the company's moat can withstand competitors' assaults.

Let's look at Baxter International (NYSE: BAX) and two of its industry peers to see how efficiently they use capital. Here are the ROIC figures for each company over several time periods:

Source: Capital IQ, a division of Standard & Poor's. *Uses 2009's effective tax rate of 19.2%.

Each of these three companies provides attractive returns on invested capital. Baxter has shown nice growth from five years ago, as has Eli Lilly -- an uptrend that suggests the companies are more firmly established competitively. Abbott has experienced a slight downdraft from five years ago, although its returns have bounced from a few years ago. To varying degrees, each of these companies shows the advantage of protected intellectual property in the health-care sector.

Businesses with consistently high ROIC are efficiently using capital. They can use their extra returns to buy back shares, further invest in their future success, or pay dividends to shareholders. (Warren Buffett especially likes that last part.)

To unearth more successful investments, dig a little deeper than the earnings headlines, and check up on your companies' ROIC.

The Motley Fool is recommending 50 stocks in 50 days for its new "11 O'Clock Stock" series. For more information, click here. Then come back to Fool.com every single weekday at 11 a.m. ET for a brand-new pick!