THURSDAY, Sept. 15 (HealthDay News) -- The facts about cancer found on the website Wikipedia are about as accurate as the information on the disease found on the patient-oriented section of the U.S. National Cancer Institute's Physician Data Query (PDQ), a comprehensive peer-reviewed cancer database, according to a new study.

Although experts from Thomas Jefferson University were hard-pressed to find errors on Wikipedia, they did find the content on the site was harder to read and included links to more dense information than the simplified, shorter explanations found on PDQ.

"There are a vast number of websites where patients can obtain cancer information," study leader Dr. Yaacov Lawrence, adjunct assistant professor of radiation oncology at Jefferson Medical College of Thomas Jefferson University, and director of the Center for Translational Research in Radiation Oncology at the Sheba Medical Center in Israel, said in a university news release.

"The purpose of this study was to answer one question: Is the cancer information on Wikipedia correct? Reassuringly, we found that errors were extremely rare on Wikipedia. But the way information was presented on PDQ is more patient-friendly," Lawrence said.

Wikipedia is commonly not considered a trustworthy source of information since the writers -- whether amateur journalists or medical specialists -- develop the content found on the site without professional oversight. Nevertheless, the study found the site ranked among the top 10 results for more search engines, higher than the PDQ and professionally maintained government websites. The study authors also pointed out that Wikipedia updates more quickly.

In conducting the study, researchers chose 10 types of cancer and compared the information on the diseases' epidemiology, etiology, symptoms, diagnosis, treatment and controversial topics in cancer care found on Wikipedia with the information found on PDQ. The content on both sites were vetted for accuracy against textbooks.

The investigators also used standard algorithms based on word and sentence length to calculate the information's readability.

The study, released online in advance of print publication in the Journal of Oncology Practice, revealed that less than 2 percent of the information on either Wikipedia or PDQ did not coincide with the facts found in textbooks. The researchers found the information on the two websites were equally comprehensive. They also noted both sites discussed controversial aspects of cancer care poorly.

The main difference between Wikipedia and the PDQ site was their readability. Wikipedia was written at a college level, while PDQ was written so that a 9th grader could understand it.

"PDQ's readability is doubtless due to the site's professional editing, whereas Wikipedia's lack of readability may reflect its varied origins and haphazard editing," explained Lawrence. "Overall our results are reassuring: on the one hand Wikipedia appears to be extremely accurate, on the other, the resources invested in the creation and upkeep of the PDQ are clearly justified."

The study authors recommend that patients use the PDQ site first so they are not inundated by complex information and hyperlinks. They added that more research is needed to determine how the differences in readability of these sites affects patients' understanding and retention of information about the disease.

More information

The American Cancer Society provides more information on cancer.