In phase 2 trial, 25 percent nitrous oxide comparable to 50 percent nitrous oxide for reducing symptoms, but with fewer adverse effects

Factors that contribute to disparities include racism, socioeconomic status and insurance status, geographic disparities

Symptoms with the highest prevalence included anosmia, weakness, fatigue, dysgeusia, myalgia, and depression

Difference increased in age-adjusted mortality rates between large metropolitan areas, rural areas from 1999 to 2019