Less than one-third of elderly women have undergone valuable bone density screening, according to a new study.

Researchers at the Medical College of Wisconsin found that just 27% of women ages 65 to 70, 25.6% of women ages 71 to 75, and less than 10% of women older than 75 underwent the test. Older women are at the highest risk for hip fractures.

Some doctors’ lack of understanding of the importance of bone density testing and the positive effects of osteoporosis treatment primarily could contribute to the under testing, the researchers noted.

The study appears in the March issue of the Journal of the American Geriatrics Society.