Freire 2008.

Methods	Randomized controlled trial with three groups (routine care; skin‐to‐skin; routine care + oral glucose)
Participants	95 preterm infants (PMA 28 to 36 weeks) Painful procedure: heel lance Study period: unclear
Interventions	Intervention: 10 minutes of skin‐to‐skin care before, during heel stick Control: standard care during painful procedure Comparison: sweet taste 2 minutes before painful procedure Provider: mother
Outcomes	PIPP score
Notes	Country: Brazil Power calculation: yes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"The groups were selected at random by a nurse on duty using closed envelopes" Not clear how the sequence was generated
Allocation concealment (selection bias)	Unclear risk	"The groups were selected at random by a nurse on duty using closed envelopes" Not clear whether the envelopes were opaque, sealed and sequentially numbered
Blinding (performance bias and detection bias) All outcomes	Low risk	"The examiner was blinded and trained to record any grimacing..." "Only the newborn's face was filmed in close‐up with little surrounding area and minimal colour to reduce the possibility of unblinding by the research assistants who recorded the tapes".
Incomplete outcome data (attrition bias) All outcomes	Low risk	There were 10 neonates excluded due to errors in the blinding of the video (30/Fig 1). Data were provided only for all other neonates
Selective reporting (reporting bias)	Low risk	All outcomes were clearly presented in Table 3
Other bias	Low risk	Study was apparently free of other sources of bias