WASHINGTON, June 12, 2012—Updated government estimates published in the journal Health Affairs indicate that health care spending in the U.S. will engulf almost one-fifth of the economy by 2021.

Actuaries from the Centers for Medicare & Medicaid Service estimated that health spending would rise from 17.9 percent of gross domestic product in 2010 to 19.6 percent in 2012.

Doctors often understate the seriousness of illnesses, and many withhold information from patients, according to a survey published last week by Health Affairs.

The survey was conducted in 2009 and included 1,891 practicing doctors nationwide. More than half of respondents indicated that they sometimes provided patients with an overly optimistic view of possible outcomes for illnesses.