Khan 2014.

Study characteristics
Methods	Design: quasi‐RCT Unit of randomisation: not specified Type of study: study on pneumonia treatment
Participants	Location/setting: study was carried out in Paediatric Department (ward), Islamic International Medical College‐Trust, (IIMC‐T), Railway Hospital, Rawalpindi, Pakistan Sample size: 222 children Dropout/withdrawals: none Sex: males and females (39% females and 61% males) Age range: 2 months to 5 years Diagnostic criteria: not specified Severity of condition: severe pneumonia
Interventions	Intervention (sample size): 200 mg oral vitamin C drops once daily until symptoms of severe pneumonia were improved (N = 111) Control (sample size): placebo drops (sodium citrate with colouring agent mixed in water) were given once daily until severe pneumonia improved (N = 111) Concomitant interventions: IV amoxicillin and supportive treatment Follow‐up: clinical progress of both groups was taken thrice daily in terms of oxygen saturation, respiratory rate, and chest indrawing. The number of days to improvement of severe pneumonia was recorded. Improvements in respiratory rates was reported in less than 4 days, chest indrawing in less than 2 days, and oxygen saturation in less than 1 day.
Outcomes	Primary outcomes: duration of Illness: mean number of days for improvement in respiratory rate, mean number of days for improvement in oxygen saturation, and mean number of days for improvement in chest indrawing Secondary outcomes: not specified Timing of outcome assessment: not specified
Notes	Study start date: 1 April 2010 Study end date: 31 March 2011 Limitations: not specified Funding source: not specified Conflicts of interest: not specified
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation not done.
Allocation concealment (selection bias)	High risk	Randomisation not done.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "In other group children received placebo drops (consisted of sodium citrate along with coloring agent mixed in water), which matched exactly with vitamin C drops in color and taste." (p. 56) Comment: adequately done
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "In other group children received placebo drops (consisted of sodium citrate along with colouring agent mixed in water), which matched exactly with vitamin C drops in colour and taste." (p. 56) Comment: insufficient information regarding outcome assessor
Incomplete outcome data (attrition bias) All outcomes	Low risk	There was no loss to follow‐up.
Selective reporting (reporting bias)	Unclear risk	We did not find a study protocol. Outcomes specified in the methodology section have been reported in the results section.
Other bias	Low risk	No other potential bias detected.