Annual mammography rates averaged only 50 percent in those ages 40 and older despite the fact that all patients studied had continuous insurance coverage, Dr. Milayna Subar of the benefits managment company Medco Health Solutions in Franklin Lakes, N.J., and colleagues found.
Biennial screening rates weren't much better, with 60 percent of the women ages 40 and older having had at least two mammograms over four years, the researchers reported here at the San Antonio Breast Cancer Symposium.
"The concern is we often listen to the loudest and forget about those who aren't shouting," Subar told MedPage Today. "We have to look at the actual data, not just what people say when they are speaking out."
When the U.S. Preventive Services Task Force (USPSTF) recommended in November 2009 that women under age 50 don't need routine screening mammography and those 50 to 75 need screening only every two years, the public and political furor led Congress to include a proviso in the healthcare reform law for insurers to cover annual mammography starting at 40.
"This is human nature; people do not want to be denied things they think they should have," noted Judy E. Garber, MD, MPH, of the Dana- Farber Cancer Institute in Boston and president-elect of the American Association for Cancer Research, which co-sponsors the conference.
The American Cancer Society and other professional associations generally recommend annual or biennial screening mammography starting at age 40.
The Healthy People 2010 goal was 70 percent of women getting a mammogram at least once every two years once they reach 40. Prior studies suggested those goals were nearly being met but used women's self-reports as a measure of adherence.
Subar's group used a de-identified administrative claims database of more than 1.5 million women age 40 and older with no prior history of breast cancer and who were continuously insured from 2006 through 2009 -- before the controversy erupted -- with benefits managed by Medco.
They found that the average rate of annual mammography didn't differ substantially across age groups, at 47 percent among those in their 40s, 54 percent among those 50 to 64, and 45 percent among women 65 and older.
Similarly, the proportion with at least two mammograms over the four years was 57 percent in women in their 40s, 65 percent in 50- to 64-year-olds, and 53 percent in those 65 and older.
The percentage who had received any mammogram over the four years stood at 77 percent overall for those 40 and older.
Reasons for the "lower than expected" adherence rates may include patient concerns about cost, discomfort of the procedure, and fear, Subar noted at a press conference.
"This is no different from colonoscopies," Garber told MedPage Today. "We have the same data that colonoscopies are beneficial but we have a hard time getting people to do them."
Confusion after the emotional public debate over conflicting breast cancer screening guidelines could be a problem as well, Subar noted.
However, since these findings came from data prior to the USPSTF guideline update, that wouldn't explain the results, Garber countered.
"These women thought they were supposed to go every year, they just didn't get there," she said in the interview. "The confusion may make it worse."
The solution may lie in continued public education and access to mammography, according to Subar.
"There is a lot of work to be done," she concluded at the press conference.