The Bipolar Functional Status Questionnaire (BFSQ) is a novel patient-reported instrument designed to assess day-to-day functioning among patients with bipolar disorder. The development and psychometric evaluation of the BFSQ are described.

Constructs of the BFSQ were identified through literature review, expert consultation, and patient interviews. Iterative sets of interviews with additional patients were conducted to inform item reduction and revisions. 596 patients completed the BFSQ and a series of other patient- and clinician-reported health assessments during a multi-site validation study. Participants included three patient groups: 148 patients who were hypomanic or recently recovered from a manic episode within the last month, 215 patients who were currently depressed or recently recovered from a dysthymic episode within the last month, and 233 patients whose mood had been stable for a minimum of 2 months. Test-retest was assessed in 187 stable patients using data from a second administration. Additional analysis evaluated the factor structure, internal consistency, reliability, and validity.

Exploratory and confirmatory factor analyses indicated that a one-factor structure best fit the data, providing support for a total score. Item-level descriptive statistics, Cronbach's alphas, and validity correlations all met standard criteria. Furthermore, the BFSQ demonstrated superior ability to discriminate among the three subgroups.

The BFSQ is a psychometrically sound measure of functional status among bipolar patients. Efforts are underway to gather evidence for its responsiveness. The ultimate goal is for the BFSQ to facilitate the identification of treatments, which maximize functional status and ultimately improve patient adherence to treatment.