Mattos 2008.

Study characteristics
Methods	Study design: randomized controlled, parallel‐group trial Setting/country: Universidade de Sao Paulo, Institute of Urology, Sao Paulo, Brazil Dates study conducted: NR
Participants	Inclusion criteria: Age 24–59 years with a clinical diagnosis of lifelong PE according to the DSM‐IV criteria IELT ≤ 90 seconds, without previous treatments A score at the IIEF‐Erectile Function domain ≥ 26 In a stable relationship with the same partner for previous ≥ 6 months Exclusion criteria: Diabetes Contraindication to the use of any medication involved in study Abuse of alcohol or use of illicit narcotics Total number of participants randomized: 60 Total length of study: 12 weeks Group 1 (fluoxetine): Number of participants randomized: 15 Age (mean): 50 (SD 8.51) years Baseline IELT (mean): 56.55 (SD 18.55) seconds Group 2 (placebo): Number of participants randomized: 15 Age (mean): 45.93 (SD 9.96) years Baseline IELT (mean): 49.86 (SD 18.53) seconds Group 3 (fluoxetine + tadalafil): Number of participants randomized: 15 Age (mean): 42.81 (SD 7.73) years Baseline IELT (mean): 49.57 (SD 25.57) seconds Group 4 (placebo + tadalafil): Number of participants randomized: 15 Age (mean): 43.2 (SD 11.3) years Baseline IELT (mean): 49.26 (SD 19.43) seconds
Interventions	Group 1: fluoxetine 90 mg daily Group 2: placebo daily Group 3: fluoxetine 90 mg daily + tadalafil 20 mg on‐demand Group 4: placebo + tadalafil 20 mg on‐demand
Outcomes	Primary outcomes: IELT How measured: wrist stopwatch measured by participant Time points measured: every 3 weeks Safety outcomes: Adverse effects How measured: reported by participants Time points measured: anytime
Funding sources	None
Declarations of interest	NR
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "four groups were randomly distributed…chosen blindly from one envelope with numbers and another envelope with colors designating a treatment."
Allocation concealment (selection bias)	Low risk	Quote: "…were concealed by a third party that blinded the placebo and active capsules to the investigator and patients alike."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Appropriate blinding. Quote: "neither the investigator nor the patient knew which treatment was being used."
Blinding of outcome assessment (detection bias) Participant‐reported outcomes	Low risk	Quote: "… were concealed by a third party that blinded the placebo and active capsules to the investigator and patients alike."
Blinding of outcome assessment (detection bias) Investigator‐assessed outcomes	Unclear risk	Not explicitly described who was assessing adverse effects.
Blinding of outcome assessment (detection bias) IELT	Low risk	Objective measurement that was unlikely to be influenced by blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants randomized were included.
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Low risk	No source identified.