X-search: an open access interface for cross-cohort exploration of the National Sleep Research Resource

Table 2 Summary information for each of the nine datasets

Dataset	Visit(s)	No. of variables	No. of subjects	No. of mapped variables
SHHS	shhs1	1266	5804	615
	shhs2	1302	4080	592
CHAT	baseline	2897	464	826
	followup	2897	453	823
HeartBEAT	baseline	859	318	158
	followup	731	301	103
CFS	visit5	2871	735	1023
SOF	visit8	1114	461	350
MrOS	visit1	479	2911	261
	visit2	507	2911	222
CCSHS	trec	143	517	94
HCHS	sol	404	16,415	97
	sueno	505	2252	5
MESA	sleep	723	2237	512

ISSN: 1472-6947