Carmona í Farrés 2019.

Study characteristics
Methods	Randomised controlled with 2 arms Dialectical behavioral therapy ‐ mindfulness Dialectical behavioral therapy ‐ interpersonal effectiveness Duration of trial: 10 weeks Country: Spain Setting: outpatient
Participants	Method of recruitment of participants: Patients for this single‐centre randomised trial were recruited from the outpatient facility of the Hospital de la Santa Creu i Sant Pau (Barcelona, Spain). Overall sample size: 70 Diagnosis of borderline personality disorder: Structured clinical interview for DSM IV axis II personality disorders (SCID II) Means of assessment: Diagnostic interview for borderline (DIB‐R) Mean age: 31.9 years Sex: 90% female Comorbidity: no comorbidity Inclusion criteria Borderline personality disorder diagnosis based on 2 semi‐structured interviews Aged 18–50 years Not receiving any other type of psychotherapy at the time of study enrollment No previous training in mindfulness, other meditation‐contemplative practices (e.g. compassion or loving‐kindness practices), or any other mind‐body practice No comorbidities with any of the following conditions: schizophrenia, drug‐induced psychosis, organic brain syndrome, substance dependence, bipolar disorder, mental retardation, or major depressive episode in course Exclusion criteria Comorbidities with any of the following conditions: schizophrenia, drug‐induced psychosis, organic brain syndrome, substance dependence, bipolar disorder, mental retardation, or major depressive episode in course
Interventions	Experimental group Treatment name: dialectical behavioral therapy (DBT) ‐ mindfulness Number randomised to group: 35 Duration: 10 weeks Control/comparison group Comparison name: dialectical behavioral therapy (DBT) ‐ interpersonal effectiveness Number randomised to group: 35 Duration: 10 weeks Both groups Concomitant psychotherapy: not allowed to receive any other type of psychotherapy Concomitant pharmacotherapy: Patients were allowed to continue taking any medications prescribed prior to study inclusion, provided that no modifications of the medication type or dose were made during the intervention period. Proportions of participants taking standing psychotropic medication during trial observation period: unclear
Outcomes	Primary Borderline personality disorder severity, assessed by the Borderline Symptom List‐23 (BSL) Secondary Impulsivity, assessed by the Barrett Impulsiveness Scale‐11 (BIS) Attrition, in terms of patients lost after randomisation in each group
Notes	Sample size calculation: no 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: "An independent statistician randomized the participants using a computer‐generated sequence (blocks of four participants without stratification)." (Carmona í Farrés 2019 [pers comm])
Allocation concealment (selection bias)	Low risk	Quote: "An independent statistician randomized the participants using a computer‐generated sequence (blocks of four participants without stratification), allocation was concealed". (Carmona í Farrés 2019 [pers comm])
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "the evaluators of the patients were blinded to the participants' treatment arm throughout the study." (Carmona í Farrés 2019 [pers comm])
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Analyses were conducted on the per‐protocol sample, comprising participants who completed at least 80% of the intervention and for whom all data points (pre‐ and post‐intervention) were available." (Carmona í Farrés 2019, p. 5) "Analyses of primary outcomes [i.e., DERS, BIS‐11] were also conducted in the intention‐to‐treat (ITT) sample, including all enrolled participants, regardless of whether they completed the intervention or not. Missing data were treated with the last observation carried forward method (Little and Rubin 1987). Further analyses [i.e., BSL‐23] were run only for subjects considered completers." Reported data (means, SDs) which were used for effect size calculation in this review were based on completers. "Of the 70 participants who participated in the study, a total of 18 dropped out: 13 in the DBT‐M group (37.14%) and 7 (20%) from the DBT‐IE group. There were no differences between completers and non‐completers in baseline demographic characteristics." (Carmona í Farrés 2019, p. 6)
Selective reporting (reporting bias)	Low risk	Comment: Reported outcomes matched study protocol.
Other bias	Low risk	Allegiance bias: No obvious allegiance bias Adherence bias: "In relation to treatment adherence, the group sessions were witnessed by video camera, after the session a feedback to the therapists were provided, but there is no available to Spanish any validated DBT adherence tool measurement." (Soler 2019a [pers comm]). Adequate measures taken to ensure treatment adherence. Attention bias: Equal amounts of attention spent on both groups. Both the DBT‐M and DBT‐IE interventions were delivered in a group format consisting of 9–12 participants. The treatment sessions were 2.5 h in length and held once weekly over a 10‐week period.