Symon 1994.

Study characteristics
Methods	Randomised cross‐over study design 60 nasogastric feeds (20 by plunge, 30 by gravity) were given to 31 babies in the intensive care section of the study unit. No baby received more than 3 study feeds, and no baby received more than 1 study feed on any given day. All feeds were given by 1 researcher to obviate inter‐observer error, and all were given while the baby was in a sleeping or resting state
Participants	31 infants at 24 to 32 weeks' gestation (mean 28.5); at the time of feeding, corrected gestational age ranged from 26 to 37 weeks (mean 31.3) Age for plunge feeds ranged from 1 to 73 days (mean 18.6 days) and for gravity feeds from 1 to 53 days (mean 21.6 days) All participants had birth weight < 1750 grams. The average weight of babies was 1240 grams when feeds were given by plunge. and 1216 grams when feeds were given by gravity
Interventions	Push vs gravity gavage feeding
Outcomes	Respiratory rate before, during, and after feed Heart rate before, during, and after feed
Notes	No information provided (such as period between treatment changeover) regarding possible carryover effects from one treatment to another
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided. Authors state (quote): “Each feed was allocated randomly to either the gravity or plunge method”
Allocation concealment (selection bias)	High risk	Clinical staff not blinded to intervention
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	Low risk	All outcome data reported
Selective reporting (reporting bias)	Unclear risk	We were unable to obtain study protocol
Other bias	Unclear risk	No information provided (such as period between treatment changeovers) regarding possible carryover effects from one treatment to another