Gray 2015.

Methods	RCT Painful intervention: vaccination (hepatitis B) Study location: University of Chicago Hospital, Chicago, Illinois, USA Study period: July to August 2008
Participants	29 healthy, full‐term newborns undergoing vaccination Exclusion criteria included preterm birth (< 37 weeks’ completed PMA), birthweight < 2 kg, any Apgar score < 6, congenital abnormalities, medical complications, or drug exposure. Infants with previous oxygen administration, ventilatory support, or NICU admission were excluded
Interventions	Sucrose group (n = 15): 1.0 mL 24 % sucrose 2 min before vaccination Sucrose + warmth group (n = 14): 1.0 mL 24% sucrose 2 min before vaccination + radiant warmth from an infant warmer before the vaccination Infants in the sucrose + warmth group were placed under an Ohmeda Ohio Infant Warmer (Model No. 3000; GE Healthcare, Fairfield, CT), and their clothing was removed, except for a diaper (nappy)
Outcomes	Duration of cry and grimace (s), HR variability and HR
Notes	Duration of cry and grimace were provided as means and SDs and in graph form. Respiratory sinus arrhythmia and HR reported in graph form Both groups received sucrose
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "We randomly assigned each infant in the study to sucrose alone or sucrose plus warmer groups by using a sealed envelope randomisation system"
Allocation concealment (selection bias)	High risk	No information about whether the envelopes were opaque and sequentially numbered
Blinding (performance bias and detection bias) All outcomes	High risk	The study could not be blinded to warmth vs. no warmth
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Video tapes were analyzed by assessors blinded to group assignment – probably, but could the warmer be seen?
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported on all infants
Selective reporting (reporting bias)	Unclear risk	The study protocol was not available to us so we could not judge whether there were any deviations from it. We could not find a Trils registration number
Other bias	Low risk	Appears free of other bias