Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:As the study arms might not be comparable at baseline, even in RCTs, we used Becker’s strategy to adjust for the reported difference between arms at baseline when calculating SMDs; for pre-and-post intervention studies without a comparison arm and for serial cross-sectional intervention studies, we assumed the value for the comparison arm was zero [51].
Category: