The drop in hormone use by women going through menopause has contributed to a decrease in mammography use, federal researchers reported Monday.

The use of mammography to spot breast cancer increased every year since 1987 until 2005, when rates dropped for the first time. That led to speculation that the decline may have been caused by a sudden decrease in the use of hormones by women going through menopause, which fell dramatically after a federal study concluded in 2002 that the risks of the hormones outweighed the benefits. One of the downsides the study identified was an increased risk for breast cancer.

When women stop seeing their doctor for their hormone prescriptions, physicians miss a chance to remind them to get their mammograms, leading to concern that the shift could lead to decrease in the X-ray exams.

In a paper published online by the journal Cancer, Nancy Breen of the National Cancer Institute and her colleagues examined that question by analyzing data that was collected from 7,125 women ages 50 and older who were interviewed in 2000 as part of the National Health Interview Survey and 7,387 women who were interviewed in 2005

The analysis found that the decline in hormone use among women age 50 to 64 years was linked with lower mammogram rates among these women, explaining 70 percent to 80 percent of the fall in mammography use.

“Our research corroborates that a doctor’s recommendation is an important step in getting a mammogram and it shows that when circumstances change. . . it can upset the balance and lead to unanticipated and undesirable changes in mammography use,” Breen said in a statement released with the study.