Tag Archives: bias

Bias or comorbidity? Risk factors for respiratory disease aren’t always what they seem

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

Bias or comorbidityBy this point, anyone who’s been covering or following COVID-19 knows that several comorbidities substantially increase the risk of complications and severe disease. Among those mentioned most often are diabetes, heart disease and obesity.

We learned of the associations between those conditions and more severe disease first from clinical anecdotes, then case series, then observational studies. But observational studies can almost never show causation. (I don’t think they can ever, on their own, show causation, but I add the “almost” because nothing in science is ever absolute.) Although diabetes is linked to poorer outcomes with COVID-19, it doesn’t mean having diabetes causes poorer outcomes. Continue reading

Keep an eye out for lead-time bias with COVID-19 deaths

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

patient in hospital bed

Photo: Andrea Piacquadio from Pexels

Lead time bias is a well-recognized challenge especially when it comes to studies and statistics looking at cancer screenings. As the entry on the AHCJ website explains, lead time bias is a type of bias that can “artificially inflate the survival time of someone with a disease.”

How? When providers get better at looking for — and finding — a disease, it appears to lengthen the time someone survives after diagnosis. In reality, the patient is not necessarily living longer than they would have if the disease were discovered later. It just seems like they’re living longer because the disease is identified sooner, and the “clock” on survival time starts earlier. Continue reading

Book on cognitive biases and logical fallacies particularly relevant during pandemic

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

I’m pretty sure Jonathan Howard, M.D., is not psychic — but I’m not 100% sure. After all, almost nothing in science can be stated with 100% certainty. But I could be forgiven for suspecting he had some sort of premonition about the pandemic and the massive challenges it would present to clinicians, researchers, journalists and the public at large, because of the book he published less than two years ago: “Cognitive Errors and Diagnostic Mistakes: A Case-Based Guide to Critical Thinking in Medicine.” (Before you read any further, be aware that I have disclosures related to Howard that will become evident shortly.)

Howard, a psychiatrist at NYU Langone Health, spends a good deal of his free time fighting misinformation and pseudoscience online, especially on Twitter and Facebook. Continue reading

Could financial conflicts be influencing cancer care guidelines?

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

Photo: Hloom Templates via Flickr

Physicians in all fields of medicine rely on guidelines developed by professional medical organizations to inform how they care for patients. These guidelines, whether defining what counts as hypertension or laying out how best to care for pregnant women, constitute the standard of care in that particular field. To call them influential is a huge understatement.

Since most of these guidelines discuss treatments, it’s reasonable to pay attention to whether those writing the guidelines might have a bias for or against a particular treatment that’s not based on evidence. It’s impossible to be certain of this for all guideline authors, but ensuring they aren’t receiving big checks from industry is one way to guard against bias. Continue reading

Spin happens: How we cover medical studies affects readers’ attitude toward results

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

How much does the way you cover a study matter? If we judge that question on the basis of how your coverage might influence a reader’s opinion about a treatment’s benefit, it matters quite a bit, suggest the results of a recent study in BMC Medicine that examined spin in news stories about clinical studies.

In short, news articles that included spin in their coverage of a study about a particular treatment were more likely to leave readers with a positive impression of the treatment’s benefit.

Continue reading

Tylenol, antibiotics and asthma risk: Confounding by indication case study 3

Tara Haelle

About Tara Haelle

Tara Haelle (@TaraHaelle) is AHCJ's medical studies core topic leader, guiding journalists through the jargon-filled shorthand of science and research and enabling them to translate the evidence into accurate information.

Photo: Pewari via Flickr

I’ve discussed in previous blog posts ways in which confounding by indication can completely change the way observational research is interpreted: it can flip common wisdom about labor induction and cesarean delivery risk on its head, and it can lead to bizarre conversations illustrating a researchers’ blind spots when it comes to discussing topics such as depression and hormonal birth control. Continue reading