The order in which symptoms are listed on online health websites affects the outcome of self-diagnosis.

 A friend calls you up in a panic. She tells you that she has contracted a rare disease that you had never heard of until now. After a few minutes of gentle cooing and reassuring, you manage to calm her down long enough to find out that the lovely folks at WebMD or some other online health website provided this diagnosis. You smile. If this story sounds all too familiar, you are not alone.

Photo Credit: Channah

The Internet is one of the most widely used sources of health information today. In 2005, Statistics Canada reported that 35% of Canadians were seeking health information online, while the Pew Internet and American Like Project reported that 61% of Americans turned to online resources to find health information in 2009.

A recent study published in the journal Psychological Science suggests that the order in which symptoms are listed, as well as the length of the list of symptoms, on web pages like WebMD plays an important role in the public’s assessment of their health.

Arizona State University’s Virginia S. Y. Kwan and her team of researchers examined the presentation of symptom information on the top five health-information web sites in the United States: Cancer.org, Cancer.gov, WebMD, MedicineNet.com, and the New York Times Health Guide.

Using this information, they designed two studies. In the first study, the researchers looked at whether the order in which symptoms are presented on a webpage influences the chances of a positive self-diagnosis.

The scientists asked 119 Northeastern University students to complete a disease checklist for a fictional form of thyroid cancer. The checklist consisted of six symptoms, which is the average length of online symptom checklists for real forms of thyroid cancer.

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They used three types of checklists: one where three general symptoms were listed first (fluctuations in weight, shortness of breath, and feelings of being easily fatigued), one where three specific symptoms were listed first (pain in throat or neck, difficulty breathing, lump in the throat or neck), and one where general and specific symptoms were listed in alternating order.

The students had to check off the symptoms they had experienced in the last six weeks, and then they had to estimate how likely they thought they were to have thyroid cancer.

They found that the subjects’ perceived cancer risk was much higher when the general, milder symptoms where presented in streaks than when they were separated by more serious, specific symptoms.

Kwan et al., 2012

 The researchers believe that this result is caused by the feeling of checking off multiple symptoms in a row - “Surely If I am checking off multiple symptoms of this rare form of lymphoma in a row, then I must have cancerous lymphocytes!”

In addition, they found that someone who is really experiencing two or three symptoms listed one after the other was more likely to check off the following symptom, even they weren’t experiencing it at all, especially if the common symptoms were listed first.

The second study looked at whether the length of the symptom checklist dampened the effect in the first study. Previous studies have found that people who look for health information online perceive checked symptoms as indication of a greater risk of having a disease, while unchecked symptoms tend to be perceived as being “irrelevant” (instead of being perceived as an indication of a lower risk of having a disease, as one might expect).

Given these past results, the researchers wondered if adding symptoms to a list would affect the process of self-diagnosis

They asked 102 students to answer a list consisting of six symptoms or a list consisting of 12 symptoms. The researchers found that longer lists dampened the effect of symptom streaks found in the first study. The respondents who answered the longer list were less likely to believe they had the disease than those who answered the shorter list.

Kwan et al., 2012

Contrary to the first study, the order of the symptoms listed in the longer lists, whether in streaks or alternating, had no significant effect on the likelihood of a positive self-diagnosis.

The researchers hope that this paper will help online health information web sites design better self-diagnosis tools. They believe that, during periods of increased disease risk, such as the NIHI outbreak of 2009, symptom lists should be written in streaks to encourage the public to seek second opinions from trained professionals. During normal periods of risk, however, they suggest that online symptom checklists use the alternating method to reduce panic, hopefully reducing your chances of getting an anxiety-ridden call from one of your hypochondriac friends.

Kwan, V., Wojcik, S., Miron-shatz, T., Votruba, A., & Olivola, C. (2012). Effects of Symptom Presentation Order on Perceived Disease Risk Psychological Science DOI: 10.1177/0956797611432177

This work by Arielle Duhaime-Ross is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported