. Author manuscript; available in PMC: 2022 Aug 4.

Published in final edited form as: Risk Anal. 2022 Jul 13;43(6):1174–1186. doi: 10.1111/risa.13993

Appendix Table 3.

Urban-rural distribution of the selected counties (with Twitter users greater than 100) based on the 2013 National Center for Health Statistics (NCHS) Urban-Rural Classification Scheme for Counties

2013 NCHS Urban-Rural Classification	Included counties in the study		All the counties in the US
	Number of counties	Percentage	Number of counties	Percentage
Large central metro	68	6.59%	68	2.19%
Large fringe metro	249	24.13%	368	11.84%
Medium metro	239	23.16%	369	11.87%
Small metro	213	20.64%	335	10.78%
Micropolitan/Noncore	263	25.48%	1,948	62.66%
Total	1,032	100%	3,109	100%

Source: Ingram, D. D., & Franco, S. J. (2014). 2013 NCHS urban-rural classification scheme for counties: US Department of Health and Human Services, Centers for Disease Control and Prevention.