After recruiting volunteers, the implementation process is as follows: Screening and initial assessment. Volunteers are assessed with a short interview and complete self-report questionnaires (pre-test). Those who meet the entry criteria are selected to enter the random assignment stage.
In the next step, random assignment is performed. The random assignment sequence is generated using the RAND function in Excel software and simple randomization. In one column, 15 numbers code 1 (compassion-focused therapy group), 15 numbers code 2 (schema-aware acceptance and commitment therapy), and 15 numbers code 3 (control group) are entered, and 45 random numbers are generated in the adjacent column with the RAND function. The data is sorted in descending order based on the random number column, and the order of codes 1, 2, and 3 is determined completely randomly. This sequence is stored in an encrypted file.An independent researcher who has no role in administering the treatment generates the sequence and announces each participant's allocation code after they enter the study. Thus, the principal investigator who enters the participants into the study is unaware of the allocation sequence
Blinding Procedures in This Study
Due to the nature of the group-based psychological interventions, full blinding of all parties involved was not feasible. The blinding status of each role is described below:
Participants: Not blinded. Each participant was aware from the outset of their allocation to one of the two active intervention groups (Compassion-Focused Group Therapy or Schema-Informed Acceptance and Commitment Therapy) or to the waitlist control group, as the nature of group-based treatment (attendance versus non-attendance at sessions) precluded participant blinding. All participants, including those in the waitlist control group, were informed during the informed consent process, prior to enrollment, that they would be randomly allocated to one of three groups.
Principal Investigator: Not blinded. The principal investigator became aware of group allocation after the randomization process, given responsibility for coordinating intervention delivery. However, the principal investigator had no role in generating the randomization sequence (this was delegated to an independent researcher) and had no involvement in outcome assessment at post-test or follow-up, to prevent influence on results.
Therapists (intervention delivery personnel): Not blinded. The therapists (the principal investigator's student and a clinical psychology graduate student) were necessarily aware of the treatment protocol they delivered but had no role in outcome data collection or statistical analysis.
Data collectors and outcome assessors: Blinded. The outcome assessor was an individual independent of the therapy team and the principal investigator, responsible for conducting the structured clinical interview (SCID) and administering self-report questionnaires at post-test and 6-month follow-up. This individual did not attend therapy sessions, had no access to the randomization allocation file, and participants were instructed to refrain from disclosing their group assignment or session content to the assessor.
Statistical analyst: Blinded. Data were labeled with de-identified numeric codes (without group names or intervention type) prior to being provided to the statistical analyst. Primary analyses were conducted without knowledge of the correspondence between codes and group names; the decoding key was released to the analyst only after completion of the primary analyses.
Data Safety and Monitoring Board (DSMB): Given the small scale of this trial (single-center, limited sample size) and the low-risk nature of the psychological interventions, a formal DSMB was not established; safety and procedural oversight was instead conducted by the faculty supervisor and the university research ethics committee. [If a DSMB exists in your actual study, its blinding status must be reported in the same manner.]
Manuscript preparers: During preparation of the final report and descriptive analysis, the authors had access to the correspondence between codes and group names, as interpretation of findings required knowledge of intervention type. However, the primary (hypothesis-driven) statistical analyses were conducted and reported by the independent analyst prior to unblinding, to prevent biased interpretation.
Important ethical note: All participants, including those in the waitlist control group, were fully informed—prior to enrollment—of the study's research nature, the possibility of not receiving active treatment during the study period, and the guarantee of receiving effective treatment after study completion, and provided written informed consent. At no stage were participants left unaware of their participation in the research.