A new study found that more than half of seniors with dementia or almost 1.8 million Americans, have not undergone memory and thinking tests.

Researchers from the University of Michigan Health System reviewed the data of 865 people age 70 and above. The participants were assessed for dementia through interview and standard testing.

The findings showed that only 297, or 34 percent, of the participants were confirmed to have dementia. The researchers asked their family, relatives, or friends if these confirmed patients have ever consulted a doctor for memory and thinking concerns. Only 45 percent admitted that they had visited a doctor for evaluation, especially those who were married.

"It's possible that spouses feel more comfortable than children raising concerns with their spouse or a health care provider," said study author Dr. Vikas Kotagal, an assistant professor in the U-M Medical School's Department of Neurology, in a press release.

"Another possibility could be that unmarried elderly people may be more reluctant to share their concerns with their doctor if they are worried about the impact it could have on their independence."

The study failed to pinpoint the reason the seniors opt out of memory and thinking tests, but the researchers believe that there are various factors that contribute to that issue. It can be that both patients and doctors do not agree that these evaluations are beneficial, although previous studies proved that it could improve the patient's quality of life and reduce costs.

"It can help families make plans for care, help with day-to-day tasks including observed medication administration, and watch for future problems that can occur. In some instances, these interventions could substantially improve the person's quality of life," said Kotagal.

An expert agreed with the importance of memory and thinking tests for seniors and that established guidelines should be set.

"There are no established guidelines for screening procedures," said Dr. Gayatri Devi, a neurologist at Lenox Hill Hospital in New York City, to Healthday News. "As a result, many adults with dementia do not get diagnosed and are not given access to available treatments," she explained.

This study was published in the Nov. 26 issue of the journal, Neurology.