Lynn Shaffer's Research Essentials
The essentials for interpreting research and statistics
General concepts and discussions on research
Abstract for this post: The article that is the subject of this post was not written by someone who said, “I wonder …” The paper for this review is “Viral Visualizations: How Coronavirus Skeptics Use Orthodox Data Practices to Promote Unorthodox Science Online.” I’m going to assume this paper was intended to describe a scientific…
Number Needed to Treat (NNT) The number needed to treat (NNT) is based on comparing one treatment, typically a new one, with another treatment (usually the standard treatment) or perhaps with nothing. That is, it is always relative to another situation. NNT says, “by treating this number of patients with the new treatment, one additional…
What They Are Sensitivity and specificity are aspects of how well a test performs in determining whether a patient has a disease (or condition). When calculating sensitivity, you restrict your population (or denominator) to only the people who truly have the disease. For calculating specificity, you restrict your population (or denominator) to only the people…
What It Is FINER is a mnemonic for assessing the usefulness of a research question: F = Feasible I = Interesting N = Novel E = Ethical R = Relevant Suppose you’re developing a research study to see if regular exercise can reduce the need for blood pressure medication (or reduce the required dosage) in…
What It Is PICOT is a mnemonic for developing a research question: P = Population I = Intervention C = Comparison O = Outcome T = Time Frame This structure can be used to prompt the investigator to consider and specify the components of a useful research question. Each component should be linked to something…
Milk and Health is an article written by Walter Willett, MD, DrPH and David Ludwig, MD, PhD and published in the New England Journal of Medicine (February 2020). Drs. Willett and Ludwig hail from the Harvard T. H. Chan School of Public Health. Both are respected physicians and nutrition researchers. I wouldn’t be surprised if…
An ecologic study uses summary or aggregate information as the data points for analysis (i.e., units of observation). For example, an investigator may use average alcohol intake and colorectal cancer rates of various geographic regions to examine whether there is an association between alcohol intake and risk of colorectal cancer. One advantage of these studies…
My brother recently made me aware of a randomized trial testing whether famotidine (brand name: Pepcid) can prevent bad outcomes in patients with COVID-19. The idea for this came from an infectious disease physician, Michael Callahan, who was working in China when the coronavirus outbreak hit and went to Wuhan to study (?) it. Dr.…
What It Is When a researcher is assessing the nature of a relationship between a treatment and an outcome, or an exposure and an outcome, it is of interest to determine whether the relationship is the same (e.g., same direction, same strength) across all the subgroups of a population. If it isn’t the same, then…
What It Is In epidemiology, an intermediate outcome is an event that occurs within the series of steps of a proposed causal pathway that leads from an initiating exposure to an ultimate outcome of interest. In an (oversimplified) example, smoking tobacco increases activity of the sympathetic nervous system which leads to high blood pressure, which…