Will Spam Overwhelm Our Defenses? Evaluating Offerings for Drugs and Natural Health Products

S pam, the term used to describe unsolicited e-mail received from an unknown sender without expressed consent of the recipient [1], has become a major problem for communications through the Internet. Since the delivery of the fi rst spam message in 1978 [2], the volume of spam has grown tremendously. In January 2005, the percentage of all e-mails, worldwide, identifi ed as spam was estimated at 73% [3]. Spammers (the name given to those who deliver spam) are motivated by the fact that a suffi ciently large proportion of e-mail users are lured by their offers. In 2003, it was estimated that one-third of e-mail users had clicked on a Web link in a spam message, and 7% had ordered a product [4]. Despite the growing importance of spam for many industries and the public's strong interest in online health information, very little seems to be known about the relationship between spam and human health. Although it has been estimated that 10% of spam includes health-related offers [5], a search of MEDLINE on March 21, 2007, using the terms " spam, " " unsolicited e-mail, " or " junk e-mail " (limited to titles and abstracts, and using the search terms with and without a hyphen), failed to yield citations of original systematic studies on health-related spam. With this study, to our knowledge the fi rst of its kind, we hope to start fi lling this gap. Methods Sampling frame. Three accounts, unfi ltered for spam, were used to collect the data from November 1 to November 30, 2006. All accounts were based in Ontario, Canada, and were active for at least six months before data collection started. One of the accounts, which we labeled research, belonged to a member of the Centre for Global eHealth Innovation (http://www.ehealthinnovation. org/); another, labeled commercial, belonged to a commercial provider of communication services (Mountain Cablevision; http://www. mountaincable.net/); and one acted as a control and was set up to collect unsolicited messages. Selection criteria. A message was regarded as spam if it: • had been sent by an unrecognized source; • originated from a mailing list with which the recipient had no previous relationship; and • contained words with altered spelling in the subject line or included explicit unsolicited commercial offers [6]. Data extraction. All messages deemed to be spam were stored as a common dataset, and were labeled as health-related if they included …