Evaluating Health Claims: 3 Questions to Separate Fact from Fiction

Health-related studies often yield conflicting results, leaving people trying to make informed decisions about their health and well-being feeling confused and uncertain. With new health headlines emerging every week, it can be challenging to discern what is accurate and what is not. However, by asking a few key questions, individuals can cut through bias, evaluate health claims, and better understand health-related policy debates.

Key Takeaways:

• One question to ask when evaluating health claims is whether the apparent increase in a condition's rate is due to artifactual changes or true changes. Artifactual changes can occur when researchers revise how they define a condition, or when doctors become better at detecting it.
• The widespread adoption of the PSA test in the 1990s resulted in a surge in prostate cancer diagnoses, with some fraction of these cases being detected at such an early stage that they may never have progressed to cause illness or death.
• Increased awareness of a condition due to media reports or public discussion can also result in more diagnoses, especially when diagnosis is not based on a definitive medical test but instead on clinical observations or reports.
• Public health researchers consider true changes in the rates of a disease or health condition to reflect real shifts in the factors that cause a condition to become more or less common in a population. A classic example of a true change in a disease rate is smoking and lung cancer.
• The strongest studies compare a control group and an experimental group, with participants randomly assigned to one of these groups. This type of study design, called a randomized controlled trial, is considered the gold standard for proving when a treatment or other factor truly causes or prevents a disease.
• However, a randomized controlled trial cannot be used to study potentially harmful factors such as pesticides or other chemicals found in our everyday environments, so researchers need to rely on observational studies, which identify people who are already exposed to the factor in question and compare their health outcomes to those who are not.
• Because a single study cannot prove cause and effect, experts review the total body of research on a topic, including a combination of study types such as randomized clinical trials, observational studies, and laboratory research.

Statistics:

• According to the article, the rate of autism in the US has increased to 1 in 31 kids (ref. "Autism rates in US rise again to 1 in 31 kids, CDC says,"),
• The American Heart Association lowered the cutoff for diagnosing high blood pressure from 140/90 to 130/80 in 2017, resulting in more people being considered to have the condition.
• According to the author, the surgeon general's landmark report in 1964 concluded that "cigarette smoking contributes substantially to mortality from certain specific diseases and the overall death rate."

Sources:

• The Conversation -- USA (3) -- By Kimberly Johnson, Professor of Public Health, Washington University in St. Louis
• "Autism rates in US rise again to 1 in 31 kids, CDC says" (ref. unknown)
• "CDC finds nearly 1 in 3 US youth have prediabetes, but experts question scant data" (ref. unknown)
• American Heart Association report (2017)
• US surgeon general's landmark report (1964)
• The widespread adoption of the PSA test in the 1990s resulted in a surge in prostate cancer diagnoses (ref. unknown)
• The effects of chemicals in cigarette smoke have been investigated in numerous studies (ref. unknown)