Humana officials say a 57% drop in earnings at the end of last year will not lead to layoffs or other changes in the company.Humana's fourth quarter report was slightly below analysts' expectations, but spokesperson Tom Noland says the drop is not part of a trend."The report itself, this particular report, like most reports of this kind, doesn't have any immediate impact on Louisville one way or the other," he says.Noland attributes the drop to various expenses paid in the last quarter, including the acquisition of the healthcare company Concentra. He says overall, 2010 was a good year for the company, and earnings predictions for this year have been increased.