However, there was only a one-point increase, to 34 percent, in the number who expected their employers to add staff.

The  index found that accounting and finance workers were more optimistic about their job security and personal finances, and 74 percent are generally happy in their current jobs.

Across industries, U.S. managers were less confident about their firms' hiring plans in January than the previous month. Only 29 percent anticipated more hiring in the coming months, compared to 33 percent in December.  They were also slightly less optimistic than workers overall, 30 percent of whom anticipated a boost in headcount (unchanged from December).

"Whereas we typically see a new year's increase, our polling indicates that workers are approaching this year with a 'wait-and-see' attitude," said Steve Wolfe, executive vice president, Hudson, North America. "This is not a great cause for concern, though, as worker sentiment remains essentially unchanged from December, which showed increased optimism overall."