The 2006 National Health Interview Survey, conducted by the Centers for Disease Control and Prevention's National Center for Health Statistics, provides national estimates for a broad range of health measures for the U.S. civilian non-institutionalized adults.

The survey also found that 16 percent of adults did not have a usual place of healthcare, 11 percent had been told by a doctor or health professional that they had heart disease and 23 percent had been told on two or more visits that they had hypertension.

Twenty-one percent of all adults were current smokers and 21 percent were former smokers. Based on estimates of body mass index, 35 percent of adults were overweight and 26 percent were obese, the survey said.

The sample for the NHIS is redesigned and redrawn about every 10 years to better measure the changing U.S. population and to meet new survey objectives. A new sample was implemented in 2006 and data were collected for 24,275 adults.