To understand individual use of the internet and its impact on individuals, communities and societies is a challenge that is only beginning to be addressed. There are more than 580 million internet users world wide 1 , and over 16 million active users of the world-wide web in the UK 2 . This is more than the estimated number of UK smokers yet little has been done to assess the potential health impact of the internet. New developments will lead to further growth in internet usage, and this medium is increasingly being employed for health information and healthcare delivery. Clinicians need to understand the possibilities of this technology, and to be aware of potential threats to health.
THE INTERNET AS A RESOURCE FOR HEALTH INFORMATIONOne of the main uses of the internet is as an encyclopaedic information resource. Surveys consistently show that 60-80% of world-wide-web users have used it to obtain health information 3,4 . The internet has the potential to educate and empower the health consumer, by providing information on health and health services and supporting self-help and patient choice. The 'expert patient' can only become expert if he or she can access and use information, and the internet can support the increasing role of consumers in their healthcare 5 . Two-thirds of those using the internet to find health information claim it has some impact on their healthcare decisions 3 . Consumers value the anonymity, convenience and quantity of information 6 .Many concerns have been raised about the quality of online consumer health information, and the possibility that poor information has detrimental effects on health. A systematic review of 79 studies investigating the quality of online health information revealed that the methodology and rigour of these studies varies widely, as do the findings 7 . The information is often incomplete and sometimes inaccurate, although good quality material can be found. While consumers state that they pay heed to the credibility of internet sites, in practice little evaluation is carried out and users seldom remember the sites from which they retrieved information 8 . The quality of internet information needs to be examined in the wider context of imperfect health information generally 9 , and there is little reason to view the internet as radically different from other information sources 10 . While there have been isolated case reports of individuals coming to harm from information on the internet, there is no systematic evidence that more harm arises from this medium than from others 11 . DAERI (the Database of Adverse Events Related to the Internet) has been established at the University of Heidelberg to monitor this area [www.medcertain.org/daeri/]. Perhaps the difference that the internet is making to consumer health information is one of quantity rather than one of quality. The quality of information has always varied; the internet has simply increased the quantity and the ease of access. Education of consumers or content producers may help reduce the spread of poor...