The numbers tell the story

A return-on-investment (ROI) ratio of nearly seven to one is bound to raise eyebrows, but the science behind the Healthtrac program and the MEDSTAT study seems to only make that number even more impressive.

To begin with, Healthtrac drew on a database collected over 12 years on hundreds of thousands of participants to measure and predict future health costs on each employee. Using that predictive model, the company was able to identify those employees who were at the highest risk for requiring costly medical treatment in the next 12 months.

Then there was the sample itself. MEDSTAT used a population of 22,000, which is unusually large when compared to other studies of wellness programs. In addition, MEDSTAT was working from an integrated database it had already established for Citibank, which included medical eligibility information, health risk and program participation data, and absentee data.

MEDSTAT used multiple regression methodology to arrive at its conclusions. While all return-on-investment calculations compare the health care costs of participants and non-participants, MEDSTAT controlled for alternate explanations for findings, or "confounders." In other words, it considered other reasons employees might show different results, including age and gender, or the type of position they held

Finally, MEDSTAT compared the program's ROI to alternative investments Citibank could have made, such as stocks and bonds. Even when "discounting" for an 8% return had the same money been invested instead of spent on the Healthtrac program, the ROI was 6.5 to 1.