Showing posts with label confounding. Show all posts
Showing posts with label confounding. Show all posts

Wednesday, April 14, 2021

Bias in Assessing Cognitive Bias in Forensic Pathology: The Dror Nevada Death Certificate "Study"

Following the longest hiatus in the history of the Medical Evidence Blog, I return to issues of forensic medicine, by happenstance alone. In today's issue of the NYT is this article about bias in forensic medicine, spurred by interest in the trial of the murder of George Floyd. Among other things, the article discusses a recently published paper in the Journal of Forensic Sciences for which there were calls for retraction by some forensic pathologists. According to the NYT article, the paper showed that forensic pathologists have racial bias, a claim predicated upon an analysis of death certificates in Nevada, and a survey study of forensic pathologists, using a methodology similar to that I have used in studying physician decisions and bias (viz, randomizing recipients to receiving one of two forms of a case vignette that differ in the independent variable of interest). The remainder of this post will focus on that study, which is sorely in need of some post-publication peer review.

The study was led by Itiel Dror, PhD, a Harvard trained psychologist now at University College London who studies bias, with a frequent focus on forensic medicine, if my cursory search is any guide. The other authors are a forensic pathologist (FP) at University of Alabama Birmingham (UAB), a FP and coroner in San Luis Obispo, California, a lawyer with the Clark County public defender's office in Las Vegas, Nevada, a PhD psychologist from Towson University in Towson, Maryland, an FP proprietor of a Forensics company who is a part time medical examiner for West Virginia, and an FP who is proprietor of a forensics and legal consulting company in San Francisco, California. The purpose of identifying the authors was to try to understand why the analysis of death certificates was restricted to the state of Nevada. Other than one author's residence there, I cannot understand why Nevada was chosen, and the selection is not justified in the paltry methods section of the paper.

Saturday, April 26, 2014

Dear SIRS: Your Septic System Stinks

I perused with interest the April 2nd JAMA article on the temporal improvement in severe sepsis outcomes in Australia and New Zealand (ANZ) by Kaukonen et al this week.  Epidemiological studies like this remind me why I'm so fond of reading reports of RCTs:  because they're so much easier to think about.  Epidemiological studies have so many variables, measured and unmeasured, and so much confounding you have to consider. I spent at least five hours poring over the ANZ report, and then comparing it to the recent NEJM article about improved diabetes complications between 1990 and 2010, which is similar, but a bit more convincing (perhaps the reason it's in the NEJM).

I was delighted that the authors of the ANZ study twice referenced our delta inflation article and that the editorialists agree with the letter I wrote to AJRCCM last year advocating composite morbidity outcomes in trials of critical illness.  These issues dovetail - we have a consistent track record of failure to demonstrate mortality improvements in critical care, while we turn a blind eye to other outcomes which may be more tractable and which are often of paramount concern to patients.