Total compensation costs for private industry workers in metro Boston increased 1.5 percent, compared with a national gain of 2 percent, the Bureau of Labor Statistics said.

The bureau, a unit of the US Department of Labor, studied compensation costs for the 12 month period that ended in September. In compiling the data, the bureau examined 15 metropolitan areas in the United States; eight of those 15 metro areas, including metro Boston, posted compensation growth below the US average, the bureau said.