Feigenbaum 2012.

Study characteristics
Methods	12‐month trial with 2 arms Dialectical behavioral therapy (DBT) Treament‐as‐usual (TAU) Duration of trial: 1 year Country: UK Setting: outpatient
Participants	Method of recruitment of participants: from secondary and tertiary care services Sample size: 42 Diagnosis of borderline personality disorder: Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM‐IV) Means of assessment: Structured Clinical Interview for DSM‐IV axis II disorders (SCID‐II) Mean age: DBT = 35.4 years (standard deviation = 7.8), treatment‐as‐usual = 34.6 years (standard deviation = 7.4) Sex: 72‐75% female Comorbidity: mood disorders, substance abuse, anxiety disorders, eating disorders Inclusion criteria Confirmed diagnosis of cluster borderline personality disorder Aged 18‐ 65 Exclusion criteria Long‐term psychotherapeutic treatment Met DSM‐IV criteria for comorbid psychotic disorder or bipolar I disorder Had opiate dependence requiring specialist treatment Had mental impairment or evidence of organic brain disorder
Interventions	Experimental group Treatment name: dialectical behavioral therapy (DBT) Number randomised to group: 26 Duration: 1 year Control/comparison group Comparison name: treatment‐as‐usual (TAU) Number randomised to group: 16 Duration: 1 year Both groups Concomitant psychotherapy: no data Concomitant pharmacotherapy: yes, including antidepressants, antipsychotics, and mood stabilisers Proportions of participants taking standing psychotropic medication during trial observation period: "Patients were on a range of medications at time of randomization (predominantly anti‐depressants, anti‐psychotics, and mood stabilizers). Those patients entering DBT were reviewed by a consultant psychiatrist for the appropriateness of medication." (p. 129) Exact proportions of participants in each group unclear
Outcomes	Primary Self‐harm, in terms of frequency and severity of self‐harm attempts, assessed with Deliberate self harm (SASII) Suicide‐related outcomes, assessed by the Suicide Attempt SelfInjury Interview (SASII) Psychosocial functioning, assessed by the functionality subscale of Clinical Outcomes in Routine Evaluation – Outcome Measure (CORE‐OM) Secondary Anger, assessed by the the Spielberger Anger scale (STAXI); dissociation and psychotic‐like symptoms, assessed by the Dissociative Experience Scale (DES) Depression, assessed by the Beck Depression Inventory (BDI) Attrition, in terms of patients lost after randomisation in each group
Notes	Sample size calculation: yes Ethics approval: yes Comments from review authors: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Treatment allocation was made offsite via telephone randomization using a stochastic minimization programme (MINIM) balancing for sector within the regions to avoid differences in terms of differential referral practices, gender, and presence of BPD. Clients were randomized so that two of three entered DBT and one of three TAU in order to build the caseloads for staff, as this was a new service with no existing clients.” (p. 124)
Allocation concealment (selection bias)	Low risk	Quote:"Treatment allocation was made offsite via telephone randomization…” (p. 124)
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "While we attempted blinding of assessments, as is often the case with psychosocial treatment trials, those carrying out the research assessments could mostly identify the treatment group of the patient.” (p. 137)
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: “All results were analyzed using an intention‐to‐treat analysis based on treatment assignment, 15/26 dropped out in DBT and only 1/16 in TAU. Substantial differences. Unclear [for] the discontinued participants whether they completed the treatment or not.” (p. 127) “Of the 26 assigned to DBT, one withdrew consent for the data to be used at end of treatment and five refused to enter the treatment during the pre‐commitment phase. A further nine patients dropped out of therapy between months 4 and 9 of treatment. (…) Of those assigned to TAU, only one individual dropped out of receiving any form of treatment.” “Those who discontinued treatment continued to contribute data and remained in the trial.” (p. 127)
Selective reporting (reporting bias)	Unclear risk	Comment: No information
Other bias	Unclear risk	Treartment adherence: “Adherence to the therapy was not formally measured. However, adherence to the model was monitored by the team through weekly case discussion, verbal reporting of session content, and listening to each other’s audio tapes.” (p. 125) Allegiance bias: First author is Senior international trainer in DBT for British Isles DBT (https://iris.ucl.ac.uk/iris/browse /profile?upi=JFEIG65). Attention bias: “Finally, while information was collected on the types of treatments and services utilized in TAU, the number of hours of TAU intervention was not recorded, thus, it is possible that the differences identified may be due to differing intensities of treatment”. (p. 138)