Sunday, December 19, 2021

My favorite biographies and memoirs of 2021

I read so many great biographies and memoirs this year that I decided to create a separate top ten list for this type of book. Four are memoirs of physicians and a bioethicist; one is the biography of a Nobel Prize winner in chemistry; and the rest document the lives of astronauts, sports legends, and a former Secretary of State. As with my annual list of favorite public health and health care books (coming soon!), this list is ordered alphabetically and includes a few that were published before 2021.


1. All In: An Autobiography, by Billie Jean King

2. The Burning Blue: The Untold Story of Christa McAuliffe and NASA's Challenger Disaster, by Kevin Cook

3. Canary in the Coal Mine, by William Cooke

4. The Code Breaker: Jennifer Doudna, Gene Editing, and the Future of the Human Race, by Walter Isaacson

5. Endurance: My Year in Space, A Lifetime of Discovery, by Scott Kelly

6. I Came As A Shadow: An Autobiography, by John Thompson

7. In Pain: A Bioethicist's Personal Struggle with Opioids, by Travis Rieder

8. Lifelines: A Doctor's Journey in the Fight for Public Health, by Leana Wen

9. The Man Who Ran Washington: The Life and Times of James A. Baker III, by Peter Baker and Susan Glasser

10. Pilgrimage: A Doctor's Healing Journey, by Donna Chacko

Tuesday, December 14, 2021

Dietary and nutrition guidance for the holidays and beyond

As the days get shorter and people look forward to holiday celebrations, three recent dietary and nutrition guidelines provide practical advice for patients, physicians, and food vendors.

The 2020-2025 Dietary Guidelines for Americans are the latest iteration of a scientific collaboration between the U.S. Departments of Agriculture (USDA) and Health and Human Services dating back to 1980. The current report provides guidance for healthy eating across a person's lifespan, emphasizing dietary patterns with nutrient-dense foods and beverages:

At least one-half of food eaten should be fruits and vegetables, especially whole fruits and vegetables of a variety of colors. The core elements of the other half of food that should be eaten include grains, dairy, protein, and oils with lower saturated fat. At least one-half of grain servings should be whole grains. Minimize alcohol use and consumption of foods with added sugar, saturated fat, and sodium.

In an American Family Physician editorial, Drs. Amy Locke and Rachel Goossen from the University of Utah observed that "although many of the recommendations are widely accepted, ... criticisms revolve around the authors' reported financial ties to the food industry and the discrepancies between the published guidelines and the recommendations submitted to the authors by the scientific advisory committee." Examples of such discrepancies include the Dietary Guidelines' overemphasis on consuming dairy and animal-based proteins and insufficient limits on alcohol use. Drs. Locke and Goossen suggested that "the most accessible way to use the information included in the report is through the USDA's MyPlate website and app" that organize advice by food groups and subgroups.

Recognizing that nearly 9 in 10 adults consume more sodium than the National Academy of Medicine's Chronic Disease Risk Reduction (CDRR) intake of 2,300 mg/day, the U.S. Food and Drug Administration finalized voluntary guidance for industry that aims to reduce the average American's daily sodium intake by 12% (from 3,400 to 3,000 mg/day) over the next two and a half years. Industry cooperation is critical because more than 70% of sodium intake comes from packaged food and food prepared away from home. Whether these goals will be achieved in the absence of an enforcement mechanism is unclear, as the sodium content of popular commercially processed and restaurant foods has changed little over the past decade.

Finally, the U.S. Preventive Services Task Force reiterated its 2014 recommendation that found insufficient evidence to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults. In a Putting Prevention into Practice case study in AFP, Drs. Howard Tracer and Robert West noted that due to individual variability, "no one serum vitamin D level cutoff point defines deficiency, and no consensus exists regarding the precise serum levels of vitamin D that represent optimal health or sufficiency." In a previous editorial, I observed that frequent measurement of vitamin D levels in clinical practice is inconsistent with the evidence. As for supplementation, "family physicians should also counsel patients on the recommended dietary allowance for vitamin D (600 IU per day in adults 70 years and younger, and 800 IU per day in adults older than 70 years), and discourage most patients from using supplements, especially in dosages near or above the tolerable upper limit of 4,000 IU per day."


This post first appeared on the AFP Community Blog.

Saturday, December 11, 2021

Breaking the chain of transmission through vaccination

Like any other human vaccine, coronavirus vaccines aren't only meant to protect individuals from developing symptomatic COVID-19, but to break chains of transmission throughout the population, insulating vulnerable people through multiple layers of protection. Let me explain how this works. Say that the older of two unvaccinated child siblings, E.L., is exposed to a classmate with COVID-19 in the school cafeteria. What's the chance that she brings the infection home to her younger sibling, G.L., and what's the chance that younger sibling inadvertently gives the infection to Grandpa when he visits? Grandpa is vaccinated and boosted, of course, but since he has cancer and is immune compromised, he is only 60 percent less likely to catch the virus than an unvaccinated person. Let's say that due to the vagaries of distance and air circulation, the unvaccinated older sibling has a 50 percent chance of developing COVID-19 from her school exposure. Since she shares a bed with her younger sibling and doesn't go into quarantine until she has been infectious for two days, let's say that there is an 80 percent chance that if infected, she infects her sister also. This then becomes a straightforward math problem.

Probability E.L. catches COVID-19 from classmate: 0.50
Probability G.L. catches COVID-19 from E.L: 0.50 X 0.80 = 0.40
Probability Grandpa catches COVID-19 from G.L.: 0.40 X (1 - 0.60) = 0.16

So, there is about a 1 in 6 chance of an intact chain of transmission from E.L.'s classmate to E.L.'s Grandpa, via G.L. Not tremendously high, but outcomes with 1 in 6 odds happen all the time, as any sports fan can attest, and given the high risk of severe illness in immune compromised adults over age 65, most people would probably call this an unacceptable risk for Grandpa.

What if E.L. and G.L. were both fully vaccinated, though? The Pfizer-BioNTech vaccine had a reported efficacy of 90.7 percent against symptomatic disease in a randomized clinical trial of 5 to 11 year-old children; efficacy against asymptomatic transmission is uncertain, but for the sake of this scenario I will assume it's 80 percent. Let's run these calculations again, with the vaccine actions in bold.

Probability E.L. catches COVID-19 from classmate: 0.50 X (1 - 0.80)
Probability G.L. catches COVID-19 from E.L: 0.10 X 0.80 X (1 - 0.80) = 0.016
Probability Grandpa catches COVID-19 from G.L.: 0.016 X (1 - 0.60) = 0.0064

In this scenario, there is about a 1 in 156 chance of an intact chain of transmission from E.L.'s classmate to E.L.'s Grandpa, via G.L. 1 in 156 is better odds than winning the big prize in the lottery, but most people would feel pretty comfortable that an event this unlikely would not happen on any given day.

In summary, people who suggest that once Grandpa (or Grandma, or Great-Aunt Amy or other older people who are important to you or somebody else) is vaccinated and boosted, it's a "personal choice" for them and their children to get vaccinated too, are demonstrating ignorance of math and public health. We will only get through this pandemic by breaking the transmission chain together, not with 1 in 5 American adults declining vaccinations for themselves and their children because they don't think they will get very sick or that their inaction could quite possibly lead to someone else's disability or death - maybe even someone they love. I wish that every person with access to vaccination would just do the right thing and mandates wouldn't be necessary, but the declaration "I'm pro-vaccine but anti-mandate" is a non sequitur. If you're really pro-vaccine, you want everyone to get vaccinated whether they like it or not, for the good of your community and country and the whole human race.

Monday, December 6, 2021

#ThisIsOurShot at Starbucks

As the Delta variant continues to cause severe COVID-19 infections in the 40% of the U.S. population that is not fully vaccinated (71% have received at least one dose), and the more contagious Omicron variant establishes a foothold heading into winter, physicians across America are volunteering their time to reach outside of their patient panels and have community conversations about the effectiveness and safety of the vaccines. I am pleased to partner with Starbucks for a listening and informational session next week at one of their stores in southeast DC. Come have a cup with me!