Table 6. Major clusters of co-cited references of health literacy.

Cluster#	Size	Silhouette	Begin Year	End Year	Mean Year	Top Terms (log-likehood ratio, p-level)
#0	167	0.577	2004	2018	2011	patient education
#1	165	0.580	1997	2010	2005	realm
#2	154	0.821	1988	2006	1997	socioeconomic factors
#3	115	0.668	2005	2018	2012	mental health literacy
#4	92	0.983	1996	2009	2002	depression
#5	59	0.878	1996	2004	2000	physician-patient communication
#6	44	0.874	1997	2004	2001	neoplasms
#7	31	0.996	2008	2018	2013	mental health literacy
#8	27	0.950	2000	2007	2004	numeracy
#9	24	0.965	2011	2018	2014	ehealth
#10	17	0.983	2007	2017	2010	oral health
#11	9	0.993	1991	1997	1995	aids