Application of Big Data analysis in gastrointestinal research

Table 7 Examples of studies on hepatocellular carcinoma research by utilization of large healthcare datasets

Hepatocellular carcinoma
Country/Region	Database	Area of research	Sample size	Design, statistical methods and 3V	Application
Taiwan, China	Publicly available data on HCC-related genes	HCC	Not applicable	Signature inversion study	Anti-cancer effects of chlorpromazine and trifluoperazine on HCC
		Chen et al[17], 2011
				Volume, Velocity and Variety
	Connectivity Map (CMap) -- includes 6100 drug-mediated expression profiles
	Taiwan National Health Insurance Database (NHID)	HCC	4569	Nationwide retrospective cohort study	Association between NA therapy and HCC recurrence among patients with HBV-related HCC after liver resection
		Wu et al[89], 2012
				Volume, Velocity and Variety
	Taiwan National Health Insurance Database (NHID)	HCC	292290	Nationwide case-control study	Association between DM and HCC
		Chen et al[91], 2013
				Volume, Velocity and Variety
	Taiwan National Health Insurance Database (NHID)	HCC	43190	Nationwide retrospective cohort study	Association between NA therapy and HCC among CHB patients
		Wu et al[87], 2014
				PS matching
				Volume, Velocity and Variety
China	The Cancer Genome Atlas (TCGA) database	HCC	Not applicable	Signature inversion study	Anti-cancer effect of prenylamine on HCC
		Wang et al[18], 2016
				Volume, Velocity and Variety
	Connectivity Map (CMap)
South Korea	Korean Health Insurance Review and Assessment Service (HIRA)	HCC	24156	Nationwide retrospective cohort study	Difference between tenofovir and entecavir on reducing HCC risk
		Choi et al[90], 2018
				Volume, Velocity and Variety
Hong Kong, China	Clinical Data Analysis and Reporting System (CDARS)	HCC	Entire Hong Kong population between 1999 and 2012	Territory-wide retrospective cohort study	Association between NA therapy and HCC among CHB patients
		Seto et al[88], 2017
				Volume, Velocity and Variety
Sweden	Swedish Cancer Registry	HCC	9160 CHB patients	Nationwide retrospective cohort study	Association between concomitant HBV/HDV infection and HCC
		Ji et al[102], 2012
	Swedish Patient Registry
				Comparison with general population to derive SIR
				Volume, Velocity and Variety

This list is not exhaustive, but serves to provide a few distinct examples of how Big Data analysis can generate high-quality research outputs in the field of gastroenterology and hepatology. 3V: Volume/velocity/variety; HCC: Hepatocellular carcinoma; NA: Nucleos(t)ide analogue; DM: Diabetes mellitus; PS: Propensity score; CHB: Chronic hepatitis B; SIR: Standardized incidence ratio; HDV: Hepatitis D virus.