Doctors aren’t always being honest in disclosing information to Alzheimer’s patients about their condition, National Public Radio reported.

About 45 percent Alzheimer’s patients reported to the Alzheimer’s Association that their doctor had ever informed them of the diagnosis, according to a report released Tuesday.

“These disturbingly low disclosure rates in Alzheimer’s disease are reminiscent of rates seen for cancer in the 1950s and 60s,” Vice President of Constituent Services for the association, Beth Kallmyer, said in a press release.

The report found that patients were more likely to be diagnosed once the disease progressed, which could hinder the patient’s ability to make informed legal decisions about caretaking plans, according to the release.

About 5.3 million Americans suffer from the incurable disease, but surveys of doctors show they are sometimes likely to hide information from patients if they think it will cause emotional pain, the Wall Street Journal reported.

According to the Alzheimer’s Association, telling a patient of their diagnosis is important when adhering to ethical medical practice.

Dr. Pierre Tariot, a geriatric psychiatrist and director of the Banner Alzheimer's Institute in Phoenix, told NPR he finds his patients are grateful when he tells them of their Alzheimer’s diagnosis.