Gray 2000.

Methods	Randomized controlled trial
Participants	30 term infants (≥ 37 weeks) Postnatal age, range, hours: 33 to 55 Birth weight, mean (range), grams: 3300 (2600 to 3700) Painful procedure: heel lance Study period: March 1998 to October 1998
Interventions	Intervention: 10 to 15 minutes of skin‐to‐skin care before heel stick Control: standard care during painful procedure Provider: mother
Outcomes	Heart rate and cry duration in seconds during blood collection, and grimacing during recovery period
Notes	Country: United States Power calculation: yes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"They [healthy full‐term newborns] were assigned randomly the morning of the study."
Allocation concealment (selection bias)	Unclear risk	Methods of allocation concealment were not specified
Blinding (performance bias and detection bias) All outcomes	Unclear risk	"Their infant, wearing only a diaper, then was positioned on the mother so that skin‐to‐skin contact was maintained through her open gown. This arrangement left the infant’s face visible for filming from the side of the bed." "After a 2‐minute baseline period, during which the infant's face was filmed and heart rates were announced every 10 seconds from the monitor, the heel warmer was removed, and the heel was swabbed with alcohol." "videotape evaluations of infant pain reactions were conducted by research assistants who were not aware of either the purpose of the study or the number of different groups." "For grimacing, of course, knowledge of group assignment was unavoidable. The data obtained in these analyses were reliable among scorers." Not clear if mothers' skin/breasts could be noted by researchers
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data were provided for all infants randomized except grimacing in 3 infants (all in the skin‐to‐skin contact group) where blood collection lasted > 3 minutes. (3/Figure 2)
Selective reporting (reporting bias)	Low risk	Data were provided for all outcome measures listed in the methods section (Figures 2‐4)
Other bias	Low risk	"Since L.G. conducted all heel sticks because of scheduling difficulties with the phlebotomists, a potential bias of differential treatment has been introduced. We are not concerned about this potential bias for a number of reasons. First, the duration of the procedure and apparent discomfort that it caused in control infants, expressed in crying, for example, was of the same order of magnitude as that caused by the phlebotomist in other studies conducted in our laboratory. Second, as indicated, mean blood collection times for both groups were not statistically different. Third, we went through a number of iterations...before a successful set of parameters was attained. It would seem to us that any systematic bias on the part of L.G. would have become manifest from the outset and not after a number of procedural changes." Study is apparently free of other sources of bias