Table 1.

Total number of users, posts, and average sentences length for each source.

Dataset	Users, n	Posts, n	Average sentence length (in words)
TwitterHealth [16]	5,095,849	11,637,888	10.82
Google+Health [17]	86,749	186,666	9.03
Drugs.com [18]	74,461	74,461	13.85
DailyStrength/Treatments [19]	213,524	1,055,603	11.92
WebMD/Drugs [20]	122,040	122,040	13.53
Drugs.com/Answers [21]	201,126	5,948,877	6.59
DailyStrength/Forums [22]	165,045	1,128,629	13.2
WebMD [23]	155,912	320,118	15.37