Characteristics of included studies on the association of gallstones, cholecystectomy and risk of liver cancer.

Abbreviations: PB, population based; HB, hospital based; LC, liver cancer; CI, confidence interval; QS: quality score; NR, not report.♯Shanghai Women’sHealth Study (SWHS) (1996–2010).§Shanghai Men’s Health Study (SMHS) (2002–2010).Adjustment factors: 1 age, 2 BMI, 3 education, 4 smoking status, 5 alcohol consumption, 6 family history of liver cancer, 7 history of diabetes, 8 history of hepatitis/chronic liver disease, 9 physical activity, 10 total energy intake, 11, income, 12 menopausal status, 13 calendar years, 14 gender, 15 race, 16 non-steroidal anti-inflammatory drugs intake, 17 perlipidemia, 18 hepatitis B virus infection, 19 hepatitis C virus infection, 20 cirrhosis, 21 time of diagnosis, 22, chronic pancreatitis, 23 study center, 24 year of interview, 25 study period, 26 geographic region, 27, state buy-in status.Characteristics of included studies on the association of gallstones, cholecystectomy and risk of liver cancer.