Siddiqui 2013.

Methods	Single‐centre, RCT. Country: Pakistan.
Participants	67 adults aged ≥ 18 years with ARDS.
Interventions	Intervention group: PGE1 (alprostadil) 20 μg in 5 mL normal saline in a nebulizer continuously over 30 minutes. Control group: 5 mL normal saline in a nebulizer continuously over saline over 30 minutes. Used concealed syringes.
Outcomes	Primary endpoint: proportion of participants achieving 25% improvement in diastolic dysfunction, left ventricular end diastolic pressure, pulmonary artery systolic pressures and PaO2/FiO2 ratio from baseline as measured by repeat transthoracic echo and arterial blood gas analysis 30 minutes after treatment. No secondary outcomes.
Notes	Participant enrolment from May 2006 to February 2008. Contacted study author twice, 20 June 2016 and 24 March 2017 and received relevant response. Study took place in an adult, multidisciplinary, "open‐policy," 11 bed ICU in a tertiary care hospital of Karachi, Pakistan. The authors stated that measurement of pulmonary artery pressure was carried out with the application of echocardiography instead of pulmonary artery catheterization with the inherent risk of inaccuracies and bias in regards to measurements and inter‐observer variability. However, we were advised to approach the authors due to some questions in regards to the accuracy of the reported values of the pulmonary artery pressures in the publication (> 80 mmHg in both the intervention and control group). It became apparent that the authors had mistakenly reported on the systemic vascular mean systolic pressure and not the mean pulmonary artery systolic pressure. Furthermore, the authors provided additional information on lack of mortality data during the trial follow‐up. The trial was funded by the Pakistan Medical Research Council.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Parallel‐group study with balanced randomizations from a computer‐generated randomization list.
Allocation concealment (selection bias)	Low risk	Independent pharmacists dispensed either the intervention or the control from pharmacy in a syringe form concealed with aluminium foil.
Blinding (performance bias and detection bias) All outcomes	Low risk	All investigators, staff and participants were masked to outcome measurements and allocation.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	All randomized participants seemed to be accounted for in the tables. However, the authors were unable to report data on mean artery pulmonary pressure and had provided data on systemic artery pressure instead in the manuscript.
Selective reporting (reporting bias)	Low risk	Trial registration available on ClinicalTrials.gov: NCT00314548.
Other bias	Low risk	Appeared free of other bias.

For explanation of acronyms and abbreviations used in this table, see Appendix 1.