The submitted title was "Drop in US life expectancy trend not seen since 1918 influenza epidemic". A moderator changed it because it broke the site guideline: "Please use the original title, unless it is misleading or linkbait; don't editorialize."
Submitters: Cherry-picking a detail from an article is editorializing, so please don't do that. If you want to say what you think is important about the topic, please do so in a comment, where your view is on a level playing field with everyone else's.
Everyone knows it as the Spanish flu.. it's called like that because the Spanish newspapers didn't censor these deaths like the other countries that were busy with World War I
The comparison is between the last three years and 1915-1918, but the Spanish flu was just getting going in 1918.
EDIT: folks just arriving, the HN title has changed since I commented. It previously said "worst trend since Spanish flu," or something.