Farrell 2009.

Study characteristics
Methods	design: randomised controlled trial
Participants	sex: 32/32 females (100%) age: 35.6 years on average location: USA setting: outpatient exclusions: axis I diagnosis of a psychotic disorder confirmed by an open clinical interview, below average IQ level of functioning/severity of illness: mean baseline GAF score was 49.0, i.e. patients had "serious symptoms OR any serious impairment in social, occupational, or school functioning" BPD diagnosis according to: diagnostic criteria unclear means of assessment: Diagnostic Interview for Personality Disorders Revised, Borderline Syndrome Index
Interventions	group 1 (EG): Group Schema Focused Therapy + individual psychotherapy treatment as usual (GSFT + PTAU); thirty sessions of schema therapy group program in addition to weekly individual psychotherapy in the community (i.e. eclectic in orientation, primarily supportive) group 2 (CG): individual psychotherapy treatment as usual (PTAU), eclectic in orientation and primarily supportive; GSFT to be received after 14‐month waiting period duration: eight months concomitant psychotherapy: all participants were in individual psychotherapy (eclectic, mainly supportive) throughout the study concomitant pharmacotherapy: psychopharmacological treatment was not controlled for; all participants were stable on at least one psychotropic medication at the start of the study, mostly low doses of antipsychotics and/or SSRI
Outcomes	outcomes considered in this review self‐rated: BPD severity (BSI), general psychopathology (SCL‐90‐R‐GSI) observer‐rated: affective instability (DIB‐R‐affect subscale), impulsivity (DIB‐R‐impulsive subscale), interpersonal problems (DIB‐R‐interpersonal subscale), dissociation/stress‐related paranoia (DIB‐R‐cognitive subscale), mental health status (GAF) time‐points used here: eight months (post‐treatment)
Notes	analyses: per protocol (EG: N = 16, CG: N = 12)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Patients were randomly assigned using a random number table" (Farrell 2009, p. 319)
Allocation concealment (selection bias)	Unclear risk	No further details. After screening for eligibility of 40 patients, N = 8 were excluded. Reasons for exclusion are only given for 3 of them (1 declined participation, 2 did not meet inclusion criteria).Thus, N = 16 were allocated to EG, N = 16 to CG.
Blinding of outcome assessment (detection bias) All outcomes	High risk	"The DIB‐R structured interviews were conducted by two Ph.D. Clinical Psychologists not involved in treatment delivery. Efforts were made to keep them blind to treatment group membership, but for 10% of the subjects the blind was broken due to patient report." (Farrell 2009, p. 319) "Therapists were given a GAFS [Global Assessment of Function Scale] checklist to use so that the anchors for assigning scores were in front of them when they recorded their ratings. They were chosen as raters since they were removed from the hypotheses of the study, although not blind to their patients's group membership and no inter‐rater reliability was possible." (Farrell 2009, p. 319) Overall, observer‐rated outcomes were not assessed by blind raters.
Selective reporting (reporting bias)	Unclear risk	No indication for selective reporting, but Insufficient information to permit judgement of 'Yes' or 'No'.
Treatment adherence?	Low risk	"Two of the three groups had the two program developers as therapists and the third had one developer and one clinical psychologist [...] Weekly supervision meetings took place during the course of the study and random videotapes of sessions were reviewed for fidelity by the program developers. The manual developed for the study acted as an additional fidelity check. (Farrell 2009, p. 322)
Allegiance effect improbable?	High risk	"Two of the three groups had the two program developers as therapists and the third had one developer and one clinical psychologist" (Farrell 2009, p. 322)
Attention bias: equal amounts of attention to all groups (obligatory treatment components)?	High risk	More attention paid to EG participants.