Feb 12 2008

Medical Information on the Internet

Increasingly patients are turning to Google rather than their physician as a first stop when seeking health care information. The reasons for this are many and mostly obvious: the internet is easily accessible, it is private and discrete (at least most people perceive it as such), and increasingly people are turning to the internet as the repository of all human knowledge. There is also a lot of health information on the web. Just a couple of years ago health care information surpassed pornography as the number 1 type of information on the web.

This access to information is generally a good thing – more information is usually better than less information. But it does raise concerns about the quality of information on the internet, and this is especially true when using the internet as a source of medical advice.

There have been a number of studies looking at the quality and accuracy of health care information on the internet, and it is no surprise that the results are mixed. A new study, just published online in the journal Cancer, looks at the quality of medical information on website discussing breast cancer. They found that 5.2% of the information found was inaccurate. This is pretty good, but not good enough for medical information – especially when people may be relying upon this information to make preliminary health care decisions.

The authors looked at many variables – the URL extension, citing of authorship, last update, etc., in the hopes of finding some criteria they can use to predict which website are more likely to have few inaccuracies. Perhaps this can be used to automatically rate websites for their reliability. I predict any such strategy would ultimately fail as website authors will learn how to game the system – how to look reliable, just as website authors now game the search engine methods to get themselves ranked higher.

In any case, the authors found that there were almost no criteria that predicted the accuracy of the information – no short cut to quality control. Except, that is, one feature that stood out. They wrote:

The odds of inaccuracy for webpages having CAM among their topics were approximately 15.6 times those of sites not having the complementary medicine topic.

I must say, I am not surprised by this at all. Web sites promoting so-called alternative modalities were 15.6 times more likely to contain inaccurate information. And, this is not counting the CAM modalities themselves (that would be self-fulfilling) but rather they contained information about breast cancer that was simply inaccurate – as judged by two independent medical experts.

Why is this? It is difficult for me to give an answer that is not steeped in my own bias on the topic. Any speculation as to why this may be would need to be studies in follow up research to see if it is actually true. But with this caveat my guess is that website authors who are amenable to CAM topics have lower scientific and scholarly standards generally, and this is reflected in the content on their websites. I have argued before that CAM is an artificial category that exists only to carve out a niche where lower standard of evidence and logic can survive. This study, in my opinion, is partial validation.

An alternative hypothesis is that those who are engaged in fraud are likely to flock to CAM modalities because of the lower standards and because it is an area dominated by hope at the expense of skeptical analysis. That is fertile ground for charlatans and con artists. Such dubious websites are likely to contain misinformation, because misinformation is being used to set up the con – to convince people that the solution does not lie with mainstream medicine but with the miracle cure that is being sold.

Regardless of the cause, the authors final words are well heeded. They write:

Therefore, consumers who consult the Internet for information about breast cancer are likely to find accurate answers to their questions. However, they should be encouraged to maintain a healthy level of skepticism of online health information, consider the reputation of the source, and consult an appropriate clinician before taking action.

20 responses so far

20 Responses to “Medical Information on the Internet”

  1. Simonon 12 Feb 2008 at 8:36 am

    94.8% of the information is accurate? That’s superb! I would never have predicted a number so high.

    However, CAM aside, accurate information on a website can never come close to a consultation with a medical practitioner. A website may be perfectly correct to say that a brain tumour could cause headaches but a concerned Googler could easily read that as “my headache means I have cancer.” You have repeatedly shown on this site that knowledge is nothing without the critical thinking skills required to use it.

  2. jimon 12 Feb 2008 at 9:07 am

    I do have some concerns about the study results, I can’t follow the link to actually read it, but I assume they can’t have reviewed all the 40m websites that come up on google for breast cancer, so it makes me wonder if they are assessing the sites that patients would travel to. perhaps something in the study makes this clearer.

  3. Steven Novellaon 12 Feb 2008 at 10:08 am

    from their methods:

    Most consumers find online information by using general-purpose search engines rather than medical sites or portals, and most do not go beyond the first page of search results.[18] Therefore, we used 5 popular search engines – Google, Yahoo Directory, AltaVista, Overture, and AllTheWeb – to identify webpages that consumers are likely to encounter. We used Yahoo Directory because at the time that the study was performed, the nondirectory web search on Yahoo’s website was actually being carried out by Google. For each search engine, we performed 15 searches by using the most frequently encountered topics from the first 322 breast cancer-related entries in the NetWellness database of user questions[19] (Table 1). All searches were performed from June 1 to July 30, 2004. We recorded all URLs found on the first search results page, including sponsored (advertisements) and unsponsored results (n = 1585 [Fig. 1]). After we eliminated duplicate uniform resource locators (URLs), 870 remained.

  4. jonny_ehon 12 Feb 2008 at 10:58 am

    “Just a couple of years ago health care information surpassed pornography as the number 1 type of information on the web.”

    Excuse me for being dense, but what do you mean? Is it the most searched topic? Are more websites dedicated health than porn? Something else?

  5. themightylearton 12 Feb 2008 at 12:15 pm

    Less than 6% inaccurate huh? Sounds impressive, but I don’t think it is. Regardless of how little information is inaccurate, what matters most to me as a consumer (and one not knowledgeable in medicine) is how can I make sure I’m not reading the 5% portion that is wrong.

    That is why I’d trade accuracy for certainty. I would be willing to live with 50% accuracy, as long as it is clear which website is giving you the correct info.

    I currently look to WebMD to get a general idea when something bothers me, or to find any information on specific ailments. But that cannot replace the doctor. At the end of the day I would do what the doctor says, regardless of what the internet has to say.

  6. HCNon 12 Feb 2008 at 12:44 pm

    I’m amazed that the general search engines only came up with over 90% accurate information. But then again, my main concerns are vaccines and homeopathy, where online information is horrible.

    Those two issues are rife with bad information on the internet (and I understand aided by celebrities with Google PhDs who are in full page ads in newspapers). Just this morning I checked an article in a San Diego Newspaper about an outbreak of measles, and right there in a comment someone posts about thimerosal (which has never been in the MMR vaccine):

  7. petrucioon 12 Feb 2008 at 4:14 pm


    The solution to certainty is to look at several different sites and see if they match. If the first 6 sites I search tell me basically the same thing, I assume it as accurate information.

    Of course, that just resolves the issue for me, but not for the host of people that would trust the first site they’d bump into.

  8. Taluson 12 Feb 2008 at 4:48 pm

    Its good to know that 94.8% of the information is accurate but, i often find patients have misdiagnosed themselves and it can take a little diplomacy to get them to accept that the correct diagnosis.

    So to echo Simon’s comment knowledge can be good and bad depending on who is using it.

  9. haguson 13 Feb 2008 at 12:18 am

    Minor point. “dominated my hope” should be “dominated by hope”.

    I wouldn’t be surprised if alternative health bloggers tried to pick up on grammar or spelling errors in a desperate attempt to find *something* to criticize in Stephen’s often flawless blog postings.

  10. HCNon 13 Feb 2008 at 2:41 am

    Oh, dear hagus… Dr. Novella’s first name is spelled “Steven”, 😉

  11. jimon 13 Feb 2008 at 9:27 am

    The follow up with the details of the study were most appreciated, and my concerns are waived. I think this is an excellent result and in no small part due to bloggers Like Dr Novella who keep the alternative health crowd at bay by pointing out their worst practices.

  12. DevilsAdvocateon 13 Feb 2008 at 3:17 pm

    Note my choice of screen name while I ask if it is for certain that actual medical professionals would achieve a 94.8% or better accuracy rate?

  13. superdaveon 13 Feb 2008 at 10:16 pm

    there is another issue aside from quality of information, but also how does one interpret information? For example, muscle weakness is a serious neurological symptom, but a lay person who sees weakness as a symptom online may not distinguish between the everyday usage of the word weakness, (which may refer to fatigue or malaise) with a clinical definition which literally refers to the extent in which a muscle can generate power.

  14. skidooon 14 Feb 2008 at 12:50 am

    Simon wrote:

    However, CAM aside, accurate information on a website can never come close to a consultation with a medical practitioner.
    Hmm. That street runs in both directions. Ideally doctors are well-trained, their knowledge is current, etc. Realistically, patients need to take some measure of responsibility for their own care. There’s some movement toward the mean there that definitely benefits both patients and physicians.

    For example, accurate information from the Web (particularly from peer-reviewed literature) can be used to, er, inform doctors who are intractable in the face of reasonable treatment suggestions from patients. I recently dealt with a specialist who had only a general understanding of a specific treatment modality and a defensive demeanor. It was an unfortunate combination that caused unreasonable prejudice on his part. He needed a little edumacatin. The Web (PubMed and whatnot) was invaluable.

    Point made, physician humbled, problem solved. I can’t imagine having had to fight that same battle 20 years ago. I mean, I can imagine it, but ugh.

  15. Squadronon 14 Feb 2008 at 1:30 am

    Hey Steven and all the normal readers of this blag, I’ve been catching up on neurologica recently and really enjoy it. I’m glad to read a voice of reason and logic out there in the sea of websites.

    Anyway, an interesting point to add to this study would be the growing prevalence of social networking sites and well, how to put this nicely, “sites offering differing viewpoints from the mainstream scientific body”. Example, I googled “vaccine dangers” and this site was the #1 search result (obviously due to the design, the web designer specifically designed it to come up first in google… look at the sheer number of links and linkbacks…)


    Here we’ve got me, playing the role of an intrigued citizen, trying to get information on any dangers posed by vaccines… and this site comes up first. But I digress, as much as I disagree with everything that site stands for.

    On social networking sites it’s very easy to find bad information that many people agree with, and be swayed by bad science supporting that knowledge, ie. Do Not Get Vaccinated group on Facebook. Since we can’t get people to stop placing these sites up (and honestly, shouldn’t), the only solution is obviously better general education on these topics.

    Sorry for the lengthy post, but it’s an interesting note to consider. There’s a huge amount of ways people get educated by the internet nowadays.

  16. Squadronon 14 Feb 2008 at 1:41 am

    Interesting. I googled the term “vaccine dangers” and the first site I got was:


    It’s hard to find good information out there on the web. It’s seemingly far easier to throw up a bad site filled with illogical science than to go through the proper steps to make sure you’re reporting on good information and providing truly expert opinions.

    Or a facebook or myspace group for that matter. ie. Do Not Get Vaccinated group on Facebook. You have to wonder how many people’s opinions have been swayed by something off a social networking site…

  17. Squadronon 14 Feb 2008 at 11:51 am

    Sorry for the spam, guys! I’m new to leaving comments and didn’t realize they took awhile to post.

  18. […] and alternative” medicine. Not surprisingly, in my absence blog stalwarts Abel Pharmboy and Steve Novella already beat me to it in fine form. You might ask if that would in any way inhibit me from adding […]

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