Razek 2009.

Study characteristics
Methods	Quasi‐RCT study at 2 sites (maternal and child health centres) in Jordan
Participants	120 infants ages 1 to 12 months Painful procedure: Vaccination (type not specified) Study period: Not specified
Interventions	Intervention: Breastfeeding before, during, and after vaccination Control: No intervention
Outcomes	Cry duration from time of needle insertion until all crying activity stopped NIPS score during vaccination Wong‐Baker FACES Pain Rating Scale score during vaccination Heart rate before and after injection
Notes	Power calculation: No
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"All infants included in the study were divided into two equivalent groups (of 60 infants)." (p. 100) No random sequence generation. *Quasi‐RCT study
Allocation concealment (selection bias)	Unclear risk	"All infants included in the study were divided into two equivalent groups (of 60 infants)." (p. 100) Not enough information to assess how allocation was concealed. *Quasi‐RCT study
Blinding of participants and personnel (performance bias) All outcomes	High risk	"The mothers cradled their infants during breast‐feeding to maintain full‐body skin‐to‐skin contact during immunization injections." (p. 101) Personnel could not be blinded to whether or not infant was breastfeeding.
Blinding of outcome assessment (detection bias) All outcomes	High risk	"The mothers cradled their infants during breast‐feeding to maintain full‐body skin‐to‐skin contact during immunization injections." (p. 101) The researcher completing the cry duration and pain scores (NIPS, Wong‐Baker) could not be blinded to whether the infant was breastfeeding or not.
Incomplete outcome data (attrition bias) All outcomes	Low risk	"The subjects of this study were 120 infants chosen according to the following inclusion criteria: full‐term, age between 1 and 12 months old, breast‐feed, no concurrent illness." (p. 100) Outcome data reported for all 120 infants.
Selective reporting (reporting bias)	High risk	In Table 7 NIPS data are not presented consistent with the tool ‐ data is presented with scores from 0 to 4, rather than 0 to 7, and includes language from Wong‐Baker FACES Pain Rating Scale.
Sample size	Unclear risk	Between 50 and 199 infants per arm.
Other bias	High risk	Study used the Wong‐Baker FACES Pain Rating Scale, which is meant to be used for self assessment only.