The latest Bloomberg Businessweek features an article that reminds us of the importance of looking beyond just the promises and intentions of a given policy. In this case, the policy in question is corporate wellness programs.

The rise of wellness programs has been accompanied by a proliferation of medical tests. Public health guidelines recommend cholesterol screening for healthy adults once every five years and screening for diabetes only in people with high blood pressure, absent other symptoms. Wellness screenings typically test for both annually. “You have to identify and medicate tons and tons of people to prevent one or two from getting sick,” says Al Lewis, a former consultant to health plans and employers. Lewis once preached the benefits of wellness management but has became a vocal critic after the hoped-for savings didn’t materialize. Corporate human resources departments are “playing doctor,” he says.

Bruce Elliott, manager of compensation and benefits at the Society for Human Resource Management, a trade group representing HR professionals, says critics need to give wellness programs a few years to prove their effectiveness: “It’s an investment, and it’s an investment that does take some time.” Helping employees quit cigarettes or lose weight will translate to lower medical costs over three to five years, he says.

Yet even Elliott advises against using penalties to coerce workers to change behavior, and he concedes that businesses eager to put wellness programs in place aren’t always rigorous about measuring whether they get results. “The one thing that does worry me is the utter lack of metrics and, really, the utter lack of thought,” Elliott says. “We’re now more at a herd mentality.” Part of the problem is that there’s little agreement on what does work and how to measure success. A majority of companies don’t track their wellness programs’ return on investment, according to a 2011 survey by ADP (ADP), a payroll services company.

This is an excellent opportunity to direct your attention to John Hood’s exploration of the Prevention Legend.