(HealthDay)—Nurse practitioners could meet the growing need for house calls to frail, elderly Americans, but restrictions in some states may get in the way, according to research published recently in the Journal of the American Geriatrics Society.

An analysis of Medicare data showed that in 2013, nurse practitioners made more than 1.3 million nationwide, compared with 925,000 visits a year earlier. Doctors made 1.08 million home visits both years. The total number of home visits made by all types of increased from 4.9 million in 2012 to 5.2 million in 2013, the researchers found.

Most of the who made more than 1,000 house calls in 2013 were in the eastern half of country, primarily the Northeast, the researchers said. Also, nursing home residents were far more likely to receive than were home-bound seniors still living in their own homes.

The findings have "implications for both house-call providers and nursing education," lead researcher Nengliang Yao, Ph.D., an assistant professor at the University of Virginia Medical School in Charlottesville, said in a university news release. "If we want to take care of our geriatric population, we really need more providers to do so." However, regulations in many states hinder the growth of nurse practitioner numbers, Yao added.