About a quarter of Mississippi’s nursing homes rank at the bottom of a new federal rating system based on quality of care, staffing and health inspections.

The rating system by the Centers for Medicaid and Medicare Services grades thousands of nursing homes across the nation. It assigns nursing homes one to five stars, based on quality, staffing and health inspections. Much of the information was collected this year.

Louisiana led the nation in the percentage of one-star homes, with 39 percent of its 285 homes, according to the analysis. Delaware, which has 45 homes, had the largest percentage of five-star homes at 29 percent.

Officials say the goal of the rating system is to make it easier for older Americans and their families to choose nursing homes.