Okan 2007.

Methods	Randomized, blinded, cross‐over trial Painful intervention: heel lance Study location: NICU, Istanbul, Turkey Study period: not stated
Participants	31 preterm infants: mean (SD) PMA 30.5 weeks (2.7); PNA 20 days (16)
Interventions	2 mL sterile water 2 mL 20% sucrose 2 mL 20% glucose All solutions were given 2 min before heel lance. The infants were tested 3 times in a cross‐over manner
Outcomes	HR, respiratory rate, oxygen saturation and NFCS score at baseline, heel lance and at 1, 2, 3 and 4 min post heel lance; duration of first cry and total crying time
Notes	The differences in duration of crying time and blood collection were analyzed using the Friedman test Results were reported as means and SDs Adverse effects were not evaluated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Envelopes drawn randomly to determine sequence
Allocation concealment (selection bias)	High risk	Allocated by sealed envelopes. Solutions contained in identical bottles coded by nurse who was not part of the study. Did not mention whether envelopes were opaque or sequentially numbered
Blinding (performance bias and detection bias) All outcomes	Low risk	Sucrose and water solutions were provided blinded to staff
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: “Videotape records were later analyzed by two observers who were not aware of which solution was used. Each observer assessed the data independently and could not communicate their findings to the other.”
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported on all randomized 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
Other bias	Low risk	Appears free of other bias