WASHINGTON — The National Restaurant Association’s Restaurant Performance Index slipped to 99.9 in February, a 0.8% decline compared to January’s five-month high. The N.R.A. cited macroeconomic conditions as the reason for the slight decline.

“The Restaurant Performance Index decline was due largely to softer sales and traffic results, which fell in February amid higher gas prices and the impact of the payroll tax hike,” said Hudson Riehle, senior vice-president of the Research and Knowledge Group for the N.R.A. “In addition, sales and traffic comparisons were more difficult due to the extra day in February 2012 as a result of Leap Year.

“Despite the sales and traffic declines in February, restaurant operators remain generally optimistic about business conditions in the months ahead, which suggests they feel the setbacks will be temporary.”

The R.P.I.’s current situation index declined 1.4% to 98.3 in February. Restaurant operators cited the difficult comparison to February 2012 as one reason for the decline.

The Index’s expectations component stood at 101.4 in February – down slightly from January’s level of 101.6. Although restaurant operators’ outlook for sales growth remains positive, their expectations are slightly less bullish compared to January. Operators also continue to make plans for capital spending in the months ahead, with 57% planning to make a capital expenditure for equipment, expansion or remodeling in the next six months.