Most shoppers know to look beyond the price of an item to determine whether it’s a good deal. They also enter into their calculus judgments about volume and quality before making a decision. It is what US consumers sometimes call “getting the most bang for the buck”.

Policy makers rarely have the luxury of the same basic information when they make decisions about social programs. They might know one costs more than another. And they sometimes have an idea of which have been evaluated and shown to be effective. But rarely can they determine which program produces the most benefit at the least cost.

In tune with the times, cost effectiveness calculations are fast working their way up the prevention science agenda, and researchers are beginning to prise more information about “bang for buck” benefits from their studies.

Among the investigators are Diane DePanfilis, director of the Ruth H. Young Center for Families and Children at the University of Maryland and her colleagues who have been examining Family Connections, a child neglect prevention program developed by the University’s School of Medicine. Family Connections home visitors provide support to low-income families where children are at risk of neglect, for example as a result of family stresses such as unsafe housing, substance abuse, homelessness or mental illness.

The Maryland evaluation focused on “dosage” – on how much of the program in terms of weekly visits was likely to produce most benefit at least cost. A group of 154 families participated. Half were randomly chosen to receive Family Connection services for three months, the others received the same services for nine.

When the researchers compared children six months after completing the program, they found that three-month and nine-month groups did equally well in improving children’s safety. However, the nine-month program was more cost effective when it came to improving children’s behavior.

At the beginning and end of the study, each child’s behavior was assessed on a numerical scale. The researchers were able to determine that it cost the three-month program $337 to reduce the average child’s behavior problems by one point on the scale, but it cost the nine-month program only $276 per point.

So, while the naïve service shopper might lean toward the three-month program because it was less expensive overall, the smarter one might choose the nine-month version – because it was offering more bang for the buck.

• Summary of “Assessing the cost-effectiveness of Family Connections” by Diane DePanfilis, Howard Dubowitz, and James Kunz in Child Abuse & Neglect, March 2008, Volume 32, Issue 3, pp. 335-351.