Korkmaz 2017.

Methods	Single‐centre randomised controlled trial performed in Kayseri, Turkey. Allocation concealment: no. Randomisation: nurse on clinical service flipped a coin. Depending on the result, she openly prepared propranolol or physiological saline solution. Blinding of caregivers and personnel to intervention: no. Blinding of outcome ascertainment: yes (ophthalmologist). Complete follow‐up: no.
Participants	Preterm neonates (n = 205 enrolled, n = 171 analysed). Inclusion criteria: gestational age < 32 weeks, birth weight < 1500 grams and ≤ stage 2 ROP. Participants were stratified into 3 groups: no ROP; stage 1 ROP; stage 2 ROP. Intervention group: mean (SD) gestational age 28.2 (± 2.04) weeks; mean (SD) birth weight 1069 (± 289) grams. Control group: mean (SD) gestational age 28.4 (± 1.91) weeks; mean (SD) birth weight 1068 (± 284) grams. Exclusion criteria: infants with cardiovascular anomalies, renal failure, IVH > stage 1, NEC ≥ stage 2. Withdrawal criteria: renal failure, apneas, hypoglycaemia, bradycardia, hypotension, insufficient weight gain, or on parental request. Participants in the intervention group were excluded post‐randomisation if administration of propranolol was interrupted for more than 24 hours and upon failure to thrive.
Interventions	Intervention group (n = 83 analysed): oral propranolol (1 mg/ml saline solution) at a dose of 0.5 mg/kg 6‐hourly. Control group (n = 88 analysed): placebo (physiological saline solution). Duration of treatment: initiation of treatment ≥ 31 weeks' PMA. Duration of treatment not standardised and not reported.
Outcomes	Primary outcome: Incidence of laser therapy; platelet mass index. Secondary outcomes: not defined. The following outcomes were reported: platelet count, BPD, IVH, PDA, NEC, sepsis.
Notes	Dr Baştuğ (contact author) provided additional information on study methodology and data analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation was accomplished by a clinical nurse who flipped a coin. Unbalanced numbers of participants in intervention (n = 110, 54%) and control groups (n = 95, 46%).
Allocation concealment (selection bias)	High risk	Study drug was prepared openly in the neonatal unit.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of the intervention was not attempted.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors (Ophthalmologists) were blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	A total of 34/205 (17%) infants were excluded post‐randomisation due to serious adverse events of propranolol (n = 9), withdrawal of parental consent (n = 6), poor adherence to administration of propranolol (n = 13), and use of anti‐VEGF (n = 6). The vast majority of exclusions occurred in the intervention group, resulting in unbalanced numbers of dropouts (study group, n = 27/110 (25%) excluded; control group, n = 7/95 (7%) excluded).
Selective reporting (reporting bias)	High risk	No study protocol available. Trial was not registered.
Other bias	Low risk	None detected.