Han 2011.

Methods	Trial design: RCT Trial grouping: parallel Ethics and informed consent: unclear Follow‐up period: 3 days Sample size estimate: no ITT analysis: yes; number randomised: 100; number analysed: 100 Funding: sponsored by manufacturers of the interventional product
Participants	Inclusion criteria: people admitted for posterior spinal surgery Exclusion criteria: people with previous skin disease, those undergoing emergency surgery those with operation time of < 3 h Pretreatment: not stated
Interventions	Intervention group: Kang’ huier transparent strip and foam dressing Control group: routine operating room protective measures
Outcomes	PU incidence Outcome type: dichotomous outcome Reporting: fully reported Unit of measure: numbers Direction: lower is better Data value: endpoint
Identification	Sponsorship source: Shandong Province Higher Education Reform Project Country: China Setting: spinal surgery Comments: no comments Author's name: MF Green Institution: a third‐grade class‐A hospital of Qingdao city Email: none provided Address: Nursing College of Medical College of Qingdao University, Shandong 266021 China
Notes	Authors state that the 2 PUs in the intervention group occurred outside the treated area
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described, states only that participants were randomly grouped. But authors did not explain how the sequence was generated
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding impossible due to the nature of the intervention
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding impossible due to the nature of the intervention
Incomplete outcome data (attrition bias) All outcomes	Low risk	100 participants enrolled and all accounted for in the results
Selective reporting (reporting bias)	Low risk	The only outcome pre‐specified was "pressure sore"
Other bias	Unclear risk	We had only the most important data interpreted. It is possible that there may have been biases about which we are unaware.