Kono 1988.

Study characteristics
Methods	PCC and HCC in Japan
Participants	Participants: 139 (male/female: 74/65) cases, 278 (male/female: 148/130) population controls and 2575 (male/female: 1171/1404) hospital controls Inclusion criteria: aged 20‐75 years, newly diagnosed cases from Karatsu city and 9 neighbouring villages in Saga Prefecture, Japan. Hospital controls were aged 25‐75 years, free from cancer at clinical/radiological examination. Population controls were residents of Saga Prefecture, Japan Recruitment: from 1979‐1982
Interventions	N/A
Outcomes	Number of cases Stomach cancer: 139 (male/female: 74/65) cases
Green tea in exposure categories	Exposure assessment: green tea intake Lowest exposure: none or 1‐4 cups/d Intermediate exposure: 5‐9 cups/d Highest exposure: ≥ 10 cups/d
Notes	Funding: Grant‐in‐Aid, Ministry of Education, Science and Culture, Japan Statistical methods: unconditional logistic regression for hospital controls and conditional logistic regression for population controls Variables controlled in analysis: sex, age, class, smoking, consumption of mandarin oranges, fruits and others Variables controlled by matching: sex, age, class