Sequence generation | ‘Yes’ if randomisation sequence number generation is described as ‘random number table’ or ‘computer generated’. ‘No’ if randomisation is performed according to alternate admission date, odd or even number of patient ID. ‘Unclear’ if this is not specifically described in the text. |
Allocation concealment | ‘Yes’ if allocation sequence is concealed from those assigning participants to intervention groups until the moment of assignment. An opaque envelope is a typical method to achieve allocation concealment. ‘No’ if the investigator is aware of the assignment before assignment. ‘Unclear’ if the text does not give information on this item. |
Eligibility clearly described | ‘Yes’ if the inclusion and exclusion criteria are explicitly described. ‘No’ if the inclusion and exclusion criteria are vague or only a general description is provided. |
Is the outcome assessor blind to the assignment? | ‘Yes’ if the outcome assessor is unaware of the assignment of patients; outcome assessors are those who evaluate chest X-ray for inflammatory biomarkers. ‘No’ if the outcome assessor is aware of the assignment. ‘Unclear’ if the study does not report information on this item. |
Is the treatment provider blind to the assignment? | Treatment provider includes anaesthesiologist and surgeon because both provide intervention directly to patients. ‘Yes’ if they are blind to the assignment of the participant. ‘No’ if the surgeon or anaesthesiologist is aware of the assignment. ‘Unclear’ if the study does not report information on this item. |
Is the patient blind to the assignment? | ‘Yes’ if the patient is blind to the treatment assignment. ‘No’ if the patient is not blind to the treatment assignment, for instance, the patient is told about the treatment assignment after operation. ‘Unclear’ if insufficient information is provided. |
Are baseline characteristics comparable between the treatment and control arms? | ‘Yes’ if >90% of investigated parameters are not statistically different between the treatment and control arms; component studies typically list the baseline characteristics (see table 1 of original paper). ‘No’ if otherwise. ‘Unclear’ if insufficient information is provided. |
Are point estimates and measures of variability presented for the primary outcome measures? | ‘Yes’ if point estimates and measures of variability are presented for the primary outcome measures. The point estimates included median and mean, and variability includes SE and IQR. ‘No’ if these are not present. ‘Unclear’ if insufficient information is provided. |
Is the sample size calculated? | ‘Yes’ if statistical power and α level are employed to calculate estimated sample size. ‘No’ if this is not described in the text. |
Is intention-to-treat analysis employed? | ‘Yes’ if the final analysis includes every subject who is randomised according to randomised treatment assignment. ‘No’ if the final analysis includes only those who have completed the study. ‘Unclear’ if insufficient information is provided. |