Reports have been surfacing recently in several British newspapers claiming Facebook usage enables the spread of syphilis. This is based on the observation that syphilis cases have increased in three areas of Britain where Facebook usage has also increased by Dr. Peter Kelly, a director of public health in Britain.
The only reported quote given by Dr. Kelly is this: “Social networking sites are making it easier for people to meet up for casual sex. There is a rise in syphilis because people are having more sexual partners than 20 years ago and often do not use condoms.”
Aside from the ridiculous implication from the news outlets that Facebook is somehow more syphilis inducing than any other online social network, no expert has ever said that social networks caused an increase in syphilis. It was only provided as one possible explanation for an observed relationship.
This incident has, at the least, given us an excellent chance to observe how misinformation spreads in the news. Eye-grabbing headlines like “Sex diseases soaring due to Facebook romps” reflect either exaggeration and misrepresentation of the facts or a simple lack of understanding on the nature of statistics. Jeremy Anglim’s Blog provides an excellent description of the statistical reasons for which the news outlets’ claims don’t make any sense, including the classic: correlation does not imply causation.
At least one piece of the puzzle has also been ignored by nearly every outlet I’ve seen though: the raw numbers. In Teesside, one of the three areas in Britain where this link reportedly was shown, how many new syphilis cases were actually observed? Thirty. Since that’s the only number I’ve found reported, I suspect that the number of cases in the other two areas of Britain were even lower. For the news media to make claims that “social media increases syphilis” with this small a sample is not only misleading – it’s irresponsible.
Facebook’s staff seems to agree.