Kostandy 2008.

Methods	Randomized cross‐over trial
Participants	Only 10 infants (30 to 32 weeks' PMA) enrolled Postnatal age, range, days: 2 to 9 Birth weight, mean ± SD, grams: 1577 ± 327.00 Painful procedure: heel lance Study period: unclear
Interventions	Intervention: 30 minutes of skin‐to‐skin care before and during painful procedure Control: standard care during painful procedure Provider: mother provided skin‐to‐skin care
Outcomes	Cry duration at baseline, warming, heel stick, and recovery
Notes	Country: United States Power calculation: yes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomisation was by permuted block design to ensure highest possible equivalence among infants." The system of randomization is not mentioned
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	"Independent scorers of the videotapes were blind to the purpose and cross‐over design of the study." Not clear if mothers' skin/breasts could be noted by researchers
Incomplete outcome data (attrition bias) All outcomes	Low risk	"All mothers who were approached agreed to participate."
Selective reporting (reporting bias)	Low risk	Outcomes listed in methods match those reported
Other bias	Low risk	"26 subjects were needed to detect moderate difference in crying time; however, funding permitted recruitment of only 10 subjects." 24 hour between procedures ‐ carry‐over effect: "Heel sticks were done by a consistent neonatal phlebotomist who used the National Association of Neonatal Nursing's standardized heel stick procedure with a Tenderfoot(TM) spring‐loaded lancet."