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:We assessed the following aspects of study quality:
 (1) Study design (RCT, quasi-RCT, quasi-experimental
 study)
 (2) Method of allocating participants to trial arms (3) Concealment of allocation sequence from trial staff
 and from personnel who recruit participants into the trial (for RCTs)
 (4) Blinding of participants, program staff, and outcome
 assessors (we did not expect most studies in this field
 to blind participants and/or facilitators, as preliminary research suggests that these interventions often involve time and personal contact)
 (5) Baseline differences between trial arms, methods of
 controlling for differences in analyses
 (6) Attrition: percentage dropout at each follow-up,
 differential attrition between trial arms, and differences between dropouts and participants who are retained
 (7) Method of outcome assessment (e.g., ACASI, bio-
 markers, self-report)
 (8) Analytic procedures: Intention to treat, complete case,
 per-protocol, or treatment-on-the-treated
 We did not make any exclusions due to study quality, but instead report these aspects of methodological quality in the review.
Category: