The COVID-19 pandemic spawned an “infodemic,” in which too much information — including false or misleading information — spread rapidly in digital and physical environments. An infodemic causes confusion and risk-taking behaviors that can harm health. In the first three months of 2020 alone, nearly 6,000 people around the globe were hospitalized because of coronavirus misinformation. At the same time, the World Health Organization indicated that at least 800 people may have died due to misinformation related to COVID-19.

An infodemic also leads to mistrust in health authorities and undermines the public health response. “The same kinds of conspiracy theories that helped to fuel vaccine hesitancy during the COVID-19 pandemic are now undermining trust in vaccines against other diseases, including measles, as more people have lost confidence in public health experts and institutions,” warns a recent New York Times article.

Knowing how to determine if a source is credible is a practical skill everyone can learn, said the US Centers for Disease Control and Prevention (CDC). The CDC recommends a practical set of guides from the University of California San Francisco (UCSF) to help assess the credibility and accuracy of online health information.

Examine the credentials of the source to determine whether the author or organization has the required expertise and training to provide the information. Credibility is generally enhanced if the health information is provided by a medical institution, an entity that brings together medically knowledgeable professionals, or a government health agency.

Look for publications that have undergone peer review by a panel of professionals in the field; this adds to the credibility of the information. The availability of the publisher’s or author’s contact information in the form of a mailing address or phone number can also bolster the legitimacy of the information.

When assessing accuracy, determine whether the information is supported by evidence from scientific studies, other data or expert opinion. If you receive information from a medical journal, note the size and category of the study. Is the information based on a large or small sample (number of subjects/participants)? Studies with large sample sizes generally yield more robust evidence. Read the article carefully to see if the authors discuss any limitations or weaknesses of the study.

The most reliable evidence comes from randomized controlled studies (RCTs), which are often published in respected peer-reviewed scientific journals. However, other types of studies or the opinions of respected authorities in the field also can lend validity to the information. If you receive information from a secondary source such as an Internet site or a newspaper article, keep in mind that this is another person’s interpretation of the data. Is the information based on evidence from a study, on expert opinion, or is it merely the opinion of the writer?

Watch out for red flags that may indicate health misinformation. Information that has no identifiable publisher or author should not be relied on, unless it is backed up by information from other sources that meet the criteria for credibility. If the purpose of the information is primarily to sell a product, there may be a conflict of interest since the manufacturer may not want to present findings that would discourage you from purchasing the product. If you suspect that the intent is to sell you a product, consider getting additional information from a more neutral and objective source.

At other times, the source may not disclose all of the information or may have a bias that is more subtle and difficult to detect. Even well-respected medical journals or websites may have a slight bias, depending on their experience. For example, a journal targeting a specific medical specialty may not discuss other valid treatment options in other medical specialties. Although the information may be accurate, it may have a slight bias because of this particular perspective.

Note the date of publication. Given that health information is constantly changing as new discoveries are made, it is important to make sure that the information is current. If the information is based on a study done several years ago, you should look for more recent information to ensure that the information is still valid. For example, a website that has not been updated recently or an article that is several years old may not include information on new promising treatments.

Be skeptical of sensationalist claims of a “secret cure” or a “miraculous result” that no one else has heard about and that is not backed by evidence. Also, look for bad grammar or spelling errors that indicate poor quality control and may suggest cause for caution. Social media platforms are teeming with these types of health misinformation.

Take information from forums such as internet chat rooms and bulletin boards with a grain of salt. Keep in mind that the experience of one individual does not necessarily apply to you. Although such forums can provide valuable information, there are very few safeguards in place to ensure the credibility or accuracy of the information. Any individual, regardless of expertise or experience, can dispense advice. Information from such forums should be substantiated by more reliable sources of information.

Teodoro B. Padilla is the executive director of Pharmaceutical and Healthcare Association of the Philippines (PHAP). PHAP represents the biopharmaceutical medicines and vaccines industry in the country. Its members are in the forefront of research and development efforts for COVID-19 and other diseases that affect Filipinos.