NEW YORK (AP) — The U.S. saw remarkable increases in the death rates for heart disease, diabetes and some other common killers in 2020, and experts believe a big reason may be that many people with dangerous symptoms made the lethal mistake of staying away from the hospital for fear of catching the coronavirus.

The death rates — posted online this week by federal health authorities — add to the growing body of evidence that the number of lives lost directly or indirectly to the coronavirus in the U.S. is far greater than the officially reported COVID-19 death toll of nearly 600,000 in 2020-21....