Table 1. Sample Characteristics.

	Full Population	Doctor Population	Non-Doctor Sample
English-language tweets	68,108,441	265,412	268,301
Original tweets	15,179,051	75,713	58,708
Retweets	52,929,390	189,699	209,593
Original/Retweet	22.2%/77.7%	28.5%/71.5%	21.9%/78.1%
With location	45,879,039	219,694	180,119
% with location	67.4%	82.8%	67.1%
Number of users	19,664,145	43,877	228,062
With location	13,230,150	34,959	153,841
% with location	67.3%	79.9%	67.4%

Note. Table shows counts for doctors’ tweets and a random sample of non-doctor tweets drawn from the general Twitter population. We limit to English-language tweets. The category of original tweets includes reply tweets.