Ophir 1987.

Methods	Study design: 2 groups of participants were randomised in a double‐blind design Study duration: 1987
Participants	Inclusion criteria Setting: volunteers from Kaplan Hospital, Hebrew University of Jerusalem Country: Israel Relevant health status: symptoms of common cold, internasal temperature, reduction in nasal resistance Number: N = 62; treatment (32); control (30) Age: treatment: 16 to 64 years; control: 16 to 64 years Sex (M/F): 27/35 Participants with a naturally acquired common cold Exclusion criteria History of allergic rhinitis Symptoms lasting for 3 to 4 days Exudative pharyngitis, tonsillitis High‐grade fever Deviated nasal septum that obstructs the nasal airways
Interventions	Treatment group Intervention: RhinoTherm Dose, duration, frequency, administration: warm vapour inhalation via RhinoTherm at 42 °C to 44 °C at 40 L/min Warm vapour inhalation via RhinoTherm device delivering heated vapour at 42 °C to 44 °C (study group) at 40 L/min. An identical‐looking and ‐sounding instrument delivered air at room temperature (22 °C to 24 °C) to the placebo group at the flow rate of 2 L/min. A full course consisted of 2 treatments lasting 20 minutes, with 60‐ to 90‐minute intervals Control group Intervention: ambient air Dose, duration, frequency, administration: the dummy instrument used flow rate of 5%, as compared to the active device, at 20 °C to 24 °C
Outcomes	Symptom score index: Symptom score index was calculated for each day by dividing the sum of recorded on that day by 3. Symptomatic improvement was noticed in 26/32 steam‐treated participants and 7/30 placebo‐treated participants Nasal resistance: Objective measure of nasal potency the morning after treatment improved in 61% to 74% of participants in the steam‐treated group and only 6% to 8% of participants in the placebo‐treated group. There was a significant improvement in the nasal blockade index in the active group (P < 0.01)
Notes	The results of this study demonstrate a clear‐cut improvement in the symptom index in the treatment group. Symptomatic improvement at the end of the follow‐up period was reported by 92.9% of participants in the active treatment group and 84.6% of participants in the placebo group. Nasal patency was increased significantly in the active treatment group Funding source: RhinoTherm device used in study manufactured by Netzer Serani, Israel
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of randomisation was not described
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not clearly described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	An attempt was made to keep the intervention blinded by using identical‐looking and ‐sounding equipment
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessed using similar scale for placebo and intervention group
Incomplete outcome data (attrition bias) All outcomes	High risk	The attrition rate of the placebo group was more than the event rate of the placebo group
Selective reporting (reporting bias)	Low risk	No published protocol was available. All outcomes listed in the methods section of the published trial were reported in the results
Other bias	Unclear risk	None known.