Data extraction
Data was collected using the Cochrane handbook for systematic reviews of interventions v6.0 as guidance. A database was used to enter data from all eligible papers. Key data points included study design, inclusion and exclusion criteria, patient age and gender, operation, closure techniques, incision length, dressings, operating surgeon, post-operative management, time of removal, follow-up, scar cosmesis assessment used, timing of assessment, scar assessor, cosmetic outcome, and other secondary outcome measures.