Recently published chart using data from the National Health Interview Survey, 2012–2014 published by the Center for Disease Control.
via Morbidity and Mortality Weekly Report (MMWR) Quick Stats
During 2012–2014, the percentage of adults aged ≥18 years who reported looking up health information on the Internet during the previous 12 months was lower among those residing in nonmetropolitan counties (33.7%–38.9%) than among those residing in metropolitan counties (44.3%–49.0%). The percentage was lowest among adult residents of rural counties (33.7%) and highest among adult residents of large fringe metropolitan counties (49.0%). Adult residents of large central, medium, and small metropolitan counties reported similar usage (44.3%–45.5%).

Source: CDC (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6449a5.htm)
Direct to the Charts Homepage and Methodology Info (Important to Review)
See Also: Health Statistics Tables for the U.S. Population: National Health Interview Survey, 2014
More than 90 tables are listed.