Neimark 2016

Methods	Study design: parallel group randomised trial. Study dates: study dates not available. Setting: outpatient, national. Country: Russia.
Participants	Inclusion criteria: men aged 20‐50 years; diagnosis of chronic abacterial prostatitis registered > 1 year ago at time of enrolment, pain in pelvic area and lower abdominal pain; presence of urinary symptoms; altered structure of prostate as assessed by rectal examination. Exclusion criteria: not available. Sample size: 37. Age (years): overall range 20‐50 years. NIH‐CPSI baseline score: not available. Sex: men.
Interventions	Group 1 (n = 17): medical therapy alone (see cointerventions). Group 2 (n = 20): breathing exercises using "Karbonik" apparatus (hypercapnic hypoxia) 10‐20 min daily for 10 days. Cointerventions: levofloxacin 500 mg/day for 10 days, tamsulosin 0.4 mg once daily for 10 days, Serenoa repens fructuum extract 1 capsule once daily, Nimesulide 1‐2 tablets daily for 5‐7 days, Samprost rectal suppositories once daily before bedtime for 10 days.
Outcomes	Urinary symptoms How measured: IPSS. Time points measured: baseline and 10 days (end of treatment). Time points reported: baseline and 10 days (end of treatment).
Funding sources	None.
Declarations of interest	None.
Notes	The active treatment apparatus invention and its patent belonged to the institution that conducted the trial (Altai State Medical University). Article in Russian.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information available to make a judgement.
Allocation concealment (selection bias)	Unclear risk	No information available to make a judgement.
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	No information available to make a judgement. Considering the visibly different interventions, blinding was unlikely.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No information available to make a judgement. Considering the visibly different interventions, blinding was unlikely.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcomes: outcome data available for all participants.
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Unclear risk	Baseline characteristics poorly reported.