Bettuzzi 2006.

Study characteristics
Methods	RCT, parallel, double‐blind in Italy
Participants	Participants: 60 men with HG‐PIN, 30 in each group Inclusion criteria: age 45‐75 years, with HG‐PIN diagnosed needle biopsies collection, not consuming green tea or taking antioxidants, not vegetarians and not under antiandrogenic therapy Recruitment: NR
Interventions	Treatment group: 3 capsules of GTEs, containing green tea catechins (200 mg each) capsules/d = total 600 mg/d, corresponding to approximately 300 mg/d of EGCG Control group: placebo Duration: 1 year
Outcomes	Primary outcome Prostate cancer incidence Secondary outcomes LUTS using IPSS PSA levels QoL data Safety data
Green tea in exposure categories	N/A
Notes	Grant support: PRIN 2004 (MIUR, Italy). Dr. Rizzi was supported by Genprofiler Srl (Bolzano, Italy).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Volunteers were randomly assessed to a placebo‐ or GTCs [green tea catechins]‐arm by simple randomisation" Comment: it is unclear how sequence was generated, however the baseline characteristics reported in Table 4 are mainly equally distributed.
Allocation concealment (selection bias)	Unclear risk	Quote: "That same day [when they signed the informed consent, NDR], they were alternatively assigned to the placebo‐ or GTCs [green tea catechins]‐arm and given the appropriate treatment. To all subjects, capsules were given by the urologist according to the double blind method" Comment: insufficient information to answer
Blinding of participants and personnel (performance bias) Prostate cancer incidence	Low risk	Quote: "capsules were given by the urologist according to the double blind method" Comment: probably done
Blinding of participants and personnel (performance bias) Lower urinary tract symptoms	Low risk	Quote: "In the second arm, men received placebo (three identical capsules per day). To all subjects, capsules were given by the urologist according to the double blind method". Comment: probably done
Blinding of participants and personnel (performance bias) PSA levels	Low risk	Review authors do not believe this will introduce bias since this measurement is independent from individual evaluation
Blinding of outcome assessment (detection bias) Prostate cancer incidence	Unclear risk	No explicit statement on blinded outcome assessment
Blinding of outcome assessment (detection bias) Lower urinary tract symptoms	Unclear risk	No explicit statement on blinded outcome assessment
Blinding of outcome assessment (detection bias) PSA levels	Low risk	Review authors do not believe this will introduce bias since this measurement is independent from individual evaluation
Incomplete outcome data (attrition bias) Prostate cancer incidence	Low risk	All randomised participants were included in the analysis
Incomplete outcome data (attrition bias) Lower urinary tract symptoms	Unclear risk	Quote: "patients, diagnosed with prostate cancer at the 6 months biopsy check, left the study" Comment: number of participants included in analysis not stated
Incomplete outcome data (attrition bias) PSA levels	Low risk	All randomised participants were included in the analysis
Selective reporting (reporting bias)	Unclear risk	The study protocol is not available and it is not clear if the published reports include all expected outcomes. Insufficient information to answer
Other bias	Low risk	Study controlled for total serum PSA at the time of enrolment, prostate volume at the time of enrolment, prostate volume at the end of study, total number of HG‐PIN scores vs total scores taken at the time of enrolment, total number of HG‐PIN scores taken at the end of study; total number of mono‐focal or plurifocal HG‐PIN lesions by means of a multivariate analysis