Table 1.

Unique users tweeting about the United States Preventive Services Task Force’s recommendations on prostate cancer screening. Users were classified utilizing a coding system that demonstrated excellent agreement between two independent reviewers (κ = 0.84).

User Type	Description	Draft	Finalized
		Number (%)
TOTAL		1591	3848
Person		542 (34)	1682 (44)
Physician	Medical doctor	80 (5.0)	161 (4.2)
Health Enthusiast/Professional	Non-medical doctor health professional or self-reported health enthusiast	133 (8.4)	272 (7.1)
Reporter	Reporter working for a news agency or radio station	71 (4.5)	158 (4.1)
Blogger	Person with a blog or listed as a blogger	64 (4.0)	192 (5.0)
Political	Politician, employee thereof, or heavily lists a political affiliation	23 (1.4)	72 (1.9)
Affected	Person affected by prostate cancer, either as a patient, relative, or friend	18 (1.1)	25 (0.6)
Other	Person not otherwise included above	153 (9.6)	802 (20)
Group		576 (36)	1177 (31)
Medical Practice	Group practice, hospital, hospital network, or other center that provides medical services	18 (1.1)	30 (0.8)
Health Business	Business providing health services for profit other than inpatient or outpatient care (i.e. insurance, products)	66 (4.1)	155 (4.0)
Health Organization	Groups with a specific interest in health, not included above (i.e. research foundations, medical journals, nonprofit groups)	31 (1.9)	109 (2.8)
Health News Provider	News provider specializing in delivering health-related news and information to the Twitter community, including automatic newsfeeds	123 (7.7)	244 (6.3)
General News Provider	News provider of general news to the Twitter community, including automatic newsfeeds	185 (11.6)	370 (9.6)
Other	Group not otherwise included above	79 (5.0)	272 (7.1)
Indeterminate	No information, or information provided unable to categorize into above categories	547 (34)	986 (26)