Johnston 2008.

Methods	Randomized cross‐over trial
Participants	61 preterm infants (PMA 30.5 ± 1 weeks) Postnatal age, range, days: 1 to 14 Birth weight, mean ± SD, grams: 1421 ± 490 Painful procedure: heel lance Study period: April 2003 to December 2005
Interventions	Intervention: 15 minutes of skin‐to‐skin care before and during heel stick Comparison: swaddling in incubator 15 minutes before painful procedure Provider: mother
Outcomes	PIPP score at 30, 60, 90 and 120 minutes Time to return to baseline heart rate
Notes	Country: Canada Power calculation: yes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Ordering of conditions was determined randomly by a computer‐generated program in the study centre and assignment was accessed on the web site by the site research nurse after consent was obtained."
Allocation concealment (selection bias)	Low risk	"...assignment was accessed on the web site by the site research nurse after consent was obtained."
Blinding (performance bias and detection bias) All outcomes	Low risk	"The camera was in close up focus on the infant's face with very little surrounding area, no sound, with minimal colour, and turned to an angle in the kangaroo condition as to mimic the prone position in order to decrease the possibility of unblinding by research assistants who scored the tapes. Research assistants, who were blinded to the purpose of the study by being told that the study was about infant facial actions, coded facial actions in the laboratory of the PI."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes were clearly presented for all infants included in the study. Dropout rates were detailed in Figure 2
Selective reporting (reporting bias)	Low risk	Data were clearly reported for all outcome measures in Figures 2‐5
Other bias	Low risk	Study was apparently free of other sources of bias