Table 1.

Statistics (counts) for the observed online health forums (OHFs), rounded to thousands.

OHF community discussion topic	Total messages	Total threads	Threads of >1 posts	Contributing users
Heart Disease	104,000	32,000	23,000	31,000
Diabetes	14,000	4000	3000	5000
Substance Abuse	760,000	81,000	78,000	52,000
Fitness	19,000	5000	4000	9000
Depression	58,000	13,000	12,000	14,000
Heart Rhythm	90,000	18,000	17,000	15,000
Anxiety	166,000	34,000	30,000	33,000