Batista 2014.

Methods	Quasi‐randomised controlled trial.
Participants	16 women who sought care for engorgement at the Human Milk Bank of the Hospital Universitario Evangelico de Curitiba, Curitiba, Brazil. Inclusion criteria: women aged 18 or over who were between 3 and 10 days postpartum with moderate and/or intense bilateral engorgement, regardless of location in the breast. Exclusion criteria: women with a history of mammoplasty and/or breast prosthesis; use of synthetic oxytocin; use of analgesics in the 6 hours prior to the study; use of cream or talc on the breasts on the exam day; having had a bath up until an hour before the study; exposure to sunlight or light in the 2 hours before the study; history of a palpable or non‐palpable breast lesion; previous history of lactational mastitis; obstructive glandular engorgement; tissue integrity impaired in any region of the breast; unwilling to participate.
Interventions	Intervention group (8 participants): 1 min of electromechanical breast massage followed by mechanical pumping, if softening of the breast occurred. If no softening occurred following initial massage, then massager applied for a further 2 min before pumping. The domestically manufactured, vibro‐therapeutic massager under the trademark 'Physical' was used; whereas for milk expression a 'Medela' pump in high vibration mode, at maximum suction, was applied, first to the hands of the participant and subsequently, to their breasts. Control group (8 participants): 1 min of manual breast massage followed by manual pumping, if softening occurred. If no softening occurred following initial massage, then a further 2 min of manual massage performed prior to pumping.
Outcomes	Temperature of the breasts measured with thermography. The degree of swelling, breast tenderness and intensity of symptoms were measured before the intervention, to determine inclusion eligibility, but, unfortunately, they were not measured post‐intervention.
Notes	No information was provided on the massage technique used nor on the duration of pumping (milk expression). No statement on potential conflict of interest or source of funding is provided.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	˝The investigator flipped a coin. With the result ˝face˝, the first lactating woman would be in the control group...If it was crown˝˝, the lactating woman belonged to the experimental group...Thus the two methods of treatment were alternated starting from the initial random selection.˝
Allocation concealment (selection bias)	High risk	˝The two methods of treatment were alternated.˝
Blinding (performance bias and detection bias) Women	High risk	The types of interventions did not allow blinding of women.
Blinding (performance bias and detection bias) Clinical staff	High risk	The types of interventions did not allow blinding of clinicians.
Blinding of outcome assessment (detection bias)	Unclear risk	Blinding of outcome assessors is not mentioned and it is not clear whether the outcome assessor was independent of the clinician performing the intervention.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	A sample size of 196 women was calculated but only 16 were in the final sample. According to the authors the ˝sample was compromised due to the lack of availability of the instrumentation, the acclimatization period required for application of the thermography protocol, and the lack of signed consent forms˝. It is unclear whether women dropped out before or after study inclusion, and if afterwards, how many belonged to each group.
Selective reporting (reporting bias)	High risk	˝In the evaluation, two methods were applied: clinical exam and thermographic exam...˝ but only breast temperature is reported pre‐and post‐intervention. According to the authors, the degree of breast swelling, breast tenderness and intensity of engorgement symptoms were measured pre‐intervention but they are not reported in the article. It is unclear whether the measurements were repeated post‐intervention. The latter outcomes would have been more useful for assessing the effectiveness of the intervention, as they are common symptoms of breast engorgement, unlike a rise in breast temperature.
Other bias	High risk	Varying degrees of engorgement among women prior to treatment are alluded to but no data specifically given for study groups. A sample size of 196 women was calculated but only 16 were in the final sample suggesting that the study is severely underpowered.