. 2013 Oct 25;347:f6041. doi: 10.1136/bmj.f6041

Table 3.

Effectiveness of advice strategies for steam inhalation for symptom control (symptom severity in two to four days after seeing doctor) in patients with acute respiratory tract infections

	Crude mean (SD)		Adjusted* difference (95% CI), P value
	No steam	Steam	Adjusted* difference (95% CI), P value
Whole cohort (n=743)	1.74 (0.92)	1.70 (0.90)	−0.02 (−0.14 to 0.10), 0.75
LRTI (n=113)	1.93 (0.96)	1.75 (0.90)	0.03 (−0.27 to 0.33), 0.86
Non-LRTI (n=630)	1.71 (0.91)	1.68 (0.89)	−0.01 (−0.14 to 0.13), 0.93
Age ≤16 (n=200)	1.49 (0.79)	1.57 (0.92)	0.08 (−0.14 to 0.31), 0.46
Age ≥17 (n=543)	1.82 (0.94)	1.75 (0.89)	−0.06 (−0.20 to 0.09), 0.44

*Adjusted for baseline symptom severity, dosing, steam, antibiotic prescribing, and smoking (as smoking significantly predicted symptom severity). Outcome is severity of symptoms so lower symptom severity (or negative change) is better. Denominators vary because of missing data.