MEGAN MCARDLE: Wellness Programs Sort of Pass the Pepsi Challenge. Sort of.

A recent study by Rand found that in 2012, about half of employers with at least 50 employees — and more than 90 percent of those with more than 50,000 — had one of these programs in place.

They range from discounted gym memberships and wellness workshops to ultimatums; the Cleveland Clinic monitors its employees’ blood levels for various conditions, and it won’t have sugared soda on its campuses. Moreover, the legendary institution refuses to hire smokers, and it forced those already working for them to quit — smoking, or the job. There are also programs that focus on the behavior of people with expensive chronic conditions such as diabetes or asthma. Usually these involve a nurse regularly reaching out to these patients, cajoling them into taking their medication and monitoring their symptoms, and possibly catching potential problems early.

Such programs should reduce a company’s health-care spending. But until now, we haven’t had data showing whether they actually do.

Rand researchers have now released an article in Health Affairs that takes an in-depth look at PepsiCo Inc.’s Healthy Living program, which features both kinds of intervention: one aimed at encouraging all its employees to live healthier, and one that focuses on people who are managing chronic conditions. Unfortunately, it’s not a randomized controlled trial. But nonetheless, it does provide some information about what works, and what may not, in wellness interventions.

I’m skeptical of these innovations, which seem more like nannying than anything else. But read the whole thing.