Since 2005, the number of patients using the Internet to research prescription drug information has doubled to 102.3 million, according to a new study from Manhattan Research.

The number of e-health consumers – those going online for any health and medical information – has also grown over the past four years to 157.5 million consumers, or 1.6 times the number in 2005.

The findings come from Cybercitizen Health v9.0, the most recent consumer study from the pharmaceutical and healthcare market research company. The service is focused on how consumers use new media and technology for health information and its impact on treatment and product decisions.

Manhattan Research surveyed 8,600 U.S. adults, ages 18 and older, during the third quarter of this year for the study.

The Cybercitizen Health study has found that the major theme of the digital health landscape over the past four years is the increasing diversity of the overall patient media mix.

Health-related social media, in particular, has flourished in recent years with the increased popularity of online patient communities, social networking and health 2.0 applications. When faced with health and prescription drug decisions, the average consumer relies on a variety of channels and resources for information and support – decreasing advertisers' ability to target a particular audience through any single media outlet.

"The savvy marketer doesn't look at marketing in terms of online vs. offline," said Mark Bard, president of Manhattan Research. "Today's media consumption is so fragmented that brands need a well-connected, multi-channel strategy to keep pace with the evolving consumer market. Additionally, marketers must tailor their brand strategies in accordance to the media preferences and behaviors of individual patient groups, as disease-type is a critical factor in how consumers seek out medical information."

Bard will discuss today's digital health market and its effect on marketing and consumer engagement in a  Webinar at 11 a.m. EDT on Oct. 14. Topics include health-related media consumption across traditional and alternative resource channels, use of social media for health, emerging media formats like online video, use of major online health networks like WebMD and Everyday Health and mobile health applications.