Chen 2010a.

Methods	That "computer randomisation form was used to allocate the participants" was mentioned in the text. Traditional Chinese medicine (TCM) plus placebo group versus oseltamivir group
Participants	Participants were confirmed with influenza A H1N1 according to the Diagnostic Standard by Ministry of Health, China (Second edition, 2009). Ages ranged from 5 to 65 years and temperature was above 37.5 degrees Celsius. Patients had influenza symptoms. Patients with serious diseases of any origin, for example, kidney, heart, lung, blood vessel, nervous system, metabolic diseases, immunodeficiency diseases, tumours, hepatitis or cirrhosis, pregnant woman, or accepting hormone or immune inhibitor therapy, were excluded. In total 55 participants were included. 31 (male 18, female 13) were allocated to the TCM plus placebo group, 22 (male 9, female 13) to the control group
Interventions	Participants in the TCM group were given modified Yin Qiao Shan or Huo Bo Xia Lin Tang or Pu Ji Xiao Du Yin for the acute phase of the influenza and placebo (simulation agent of oseltamivir) 75 mg, twice a day for 5 days. In the convalescent phase, participants were given 150 ml Shang Ju Yin in the morning and evening in the TCM group. Oseltamivir was given to participants in the control group (75 mg) twice a day
Outcomes	Primary outcome: 1. Length of disease (time to symptom clearance) Secondary outcomes: 1. Length of hospitalisation 2. Rate of complications 3. Adverse events
Notes	Adverse reaction mentioned: 1 participant had diarrhea in the TCM group, 1 case of rash and 1 case of vomiting in the control group. There was no statistically significant difference between the 2 groups
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Who generated the randomisation sequence and which software was used was not mentioned; the numbers of participants in the 2 arms were not balanced (31:22). This suggests that the randomisation is questionable
Allocation concealment (selection bias)	High risk	Allocation concealment not described
Blinding (performance bias and detection bias) All outcomes	High risk	No TCM placebo was used
Selective reporting (reporting bias)	Unclear risk	There was potential selective reporting bias due to the imbalanced numbers of participants in the 2 arms 2 participants withdrew due to allergic reactions or adverse reactions
Other bias	High risk	The prescriptions were made by the authors
Blinding of participants and personnel (performance bias) All outcomes	High risk	Although a placebo was used, the participants still knew which intervention was the TCM
Blinding of outcome assessment (detection bias) All outcomes	High risk	The outcome assessors knew who took the TCM