epidemiology

Individuals who carry two copies of the APOE4 allele (APOE4/4) have about ten times the typical risk of developing Alzheimer's disease; APOE4/4 carriers constitute about 2% of the general population but represent about 15% of people diagnosed with Alzheimer's disease.

Acetaminophen is one of the most commonly used pain relievers and fever reducers in the United States, used by upward of 100 million Americans annually.

A 2025 study published in the journal Pediatrics analyzing electronic health records from pediatric practices found that the rate of peanut allergy among children ages 0–3 fell by more than 27% after 2015 guidance recommending early peanut introduction for high-risk infants and fell by more than 40% after the guidance was expanded in 2017.

A 2023 Global Burden of Disease study by researchers at NYU Langone Health, the University of Glasgow, and the Institute for Health Metrics and Evaluation (IHME) estimated that global cases of chronic kidney disease increased from 378 million in 1990 to 788 million in 2023.

A Massachusetts General Hospital study of more than 18,000 mothers and their children born between March 2020 and May 2021 found that about 5% of those mothers had COVID-19 during pregnancy and that children exposed in utero were modestly more likely to receive a neurodevelopmental diagnosis by age 3 after adjustment for maternal age, race, insurance status, and preterm birth; the association was strongest for third‑trimester maternal infection and for male offspring, and most diagnoses involved speech or motor delays.

A 2015 analysis published in The New England Journal of Medicine reported that peanut allergy prevalence among U.S. children increased from 0.4% in 1997 to more than 2% in 2010.

The World Health Organization reports that global adult obesity prevalence has more than doubled since 1990.

The U.S. Centers for Disease Control and Prevention estimates that about 1,600 people get sick from listeria infections each year in the United States and about 260 die annually.

Women are diagnosed with Alzheimer's disease nearly twice as often as men; proposed explanations for this sex difference include longer female life expectancy, hormonal changes such as shifts in estrogen during menopause, and differences in diagnostic patterns (for example, women being more likely to seek medical help for memory concerns).

A study by The George Washington University Milken Institute School of Public Health and Kaiser Permanente Southern California estimated that 18% of urinary tract infections in Southern California were linked to animal-origin E. coli strains (foodborne UTIs).

The study by The George Washington University Milken Institute School of Public Health and Kaiser Permanente Southern California reported that the highest-risk E. coli strains associated with foodborne urinary tract infections were most often found in chicken and turkey products.

Hot flashes affect an estimated 80% of women during menopause and can persist for years, interfering with sleep, concentration, and daily functioning.

A Korean study led by Jihun Song at Korea University College of Medicine reported that influenza-like illness dropped sharply during the early COVID-19 pandemic while upper respiratory infections and the common cold surged in 2023 and 2024 in Korea, and that pertussis incidence increased by more than 40-fold compared to historical trends.