Evaluation of the brief adjustment scale-6 (BASE-6): A measure of general psychological adjustment for measurement-based care

The current study evaluated the Brief Adjustment Scale-6 (BASE-6), a measure of general psychological adjustment. The psychometric properties of the BASE-6 are documented using 3 adult samples, including online participants (Sample 1: n = 459), college students (Sample 2: n = 244), and a clinical sample (Sample 3: n = 296). Acceptability ratings comparing the BASE-6 to the Outcome Questionnaire-45.2 (OQ-45.2; Lambert et al., 1996) are provided. Factor analyses showed the items were well represented by a single factor, indicating a unidimensional factor structure. The BASE-6 demonstrated good internal consistency (α =.87-.93) and there was good test-retest reliability (intraclass correlation =.77) across 1 week. In Samples 1 and 2, there was moderate to high convergent validity with the OQ-45.2 total score (r =.66-.81, p <.001), and Symptom Distress (r =.66-.80, p <.001), Interpersonal (r =.54-.68, p <.001), and Social Role (r =.57-.69, p <.001) subscales. In Sample 3, there was high convergent validity with the Patient Health Questionnaire-9 (r =.80, p <.001) and the Generalized Anxiety Disorder-7 (r =.76, p <.001). BASE-6 item and total scores were generally higher in the clinical sample compared with the nonclinical samples. Participants perceived the BASE-6 as easier to use, and more acceptable on a weekly basis compared with the OQ-45.2. Results provide preliminary evidence that the BASE-6 has acceptable psychometric properties and may show promise in the context of measurement-based care.