Wang 2002

Methods	Study design: parallel group randomised trial. Study dates: January 1998 to January 2001. Setting: outpatient. Country: China.
Participants	Inclusion criteria: not specified clearly. Participants who had a clinical diagnosis of CP. Exclusion criteria: Meares‐Stamey test and EPS routine test and culture used to exclude bacterial prostatitis. Urethral swab test used to exclude prostatitis caused by Neisseria gonorrhoeae, chlamydia or mycoplasma. Serum analysis for chlamydia and Herpes simplex virus used to exclude prostatitis caused by these micro‐organisms. Sample size: 136 (122 chronic nonbacterial prostatitis, 14 prostatodynia). Age (years): overall: 25˜54, mean 34.2. Baseline NIH‐CPSI score: not available. Sex: men.
Interventions	Group 1 (n = 76): external radiofrequency hyperthermia applied externally: 2 electrodes placed at hip and lower abdomen, 5˜7 cm away from skin, with pubic symphysis as the centre (42.5˜43.5 °C), 1˜2 hours each time, course of treatment: 2˜3 times, interval: 1˜2 weeks. Additionally, terazosin taken orally 2 mg every night for 2 days; if no serious dizziness or other adverse effects occurred, 2 mg twice daily for 12 weeks after that. Group 2 (n = 90): external radiofrequency hyperthermia: same as group 1. No terazosin. Cointerventions: none.
Outcomes	Prostatitis symptoms How measured: symptom score questionnaire developed by Neal DE Jr and Moon TD (Neal 1994). Time points measured: before and after treatment. Time points reported: before and after treatment. Subgroups: none. Adverse effects How measured: narratively.
Funding sources	Not mentioned.
Declarations of interest	Not mentioned.
Notes	None.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	'136 patients were randomly assigned to trial group (76 patients) and control group (60 patients)' (in Chinese); however, method of randomisation not described.
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not described.
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	Blinding of participants and personnel not described. Considering the visibly different interventions, blinding was unlikely.
Blinding of outcome assessment (detection bias) All outcomes	High risk	There were participant‐reported outcomes, detection bias should be high (visibly different intervention).
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 participants in trial group had missing outcome data (2.6% of attrition) because of serious adverse effect (dizziness).
Selective reporting (reporting bias)	Unclear risk	Unclear whether there was selective outcome reporting (no protocol available).
Other bias	Low risk	No other sources of bias identified.