Research

Validity and reliability of the Functioning Assessment Short Test (FAST) in bipolar disorder

Adriane R Rosa^1,2, Jose Sánchez-Moreno^2,3, Anabel Martínez-Aran², Manel Salamero², Carla Torrent², Maria Reinares², Mercè Comes², Francesc Colom², Willemijn Van Riel², Jose Luis Ayuso-Mateos³, Flávio Kapczinski¹ and Eduard Vieta²

¹  Bipolar Disorders Program & Molecular Psychiatry Laboratory, Hospital Clinic of Porto Alegre, Ramiro Barcelos, 2350, 90035-003, Porto Alegre, RS, Brazil

²  Bipolar Disorders Program, Clinical Institute of Neuroscience, Hospital Clinic of Barcelona, Villarroel 170, Barcelona 08036, Barcelona, Spain

³  Department of Psychiatry. Universidad Autonoma de Madrid. Hospital Universitario de la Princesa, Madrid, Spain

Clinical Practice and Epidemiology in Mental Health 2007, 3:5doi:10.1186/1745-0179-3-5

Published:	7 June 2007

Abstract

Background

Numerous studies have documented high rates of functional impairment among bipolar disorder (BD) patients, even during phases of remission. However, the majority of the available instruments used to assess functioning have focused on global measures of functional recovery rather than specific domains of psychosocial functioning. In this context, the Functioning Assessment Short Test (FAST) is a brief instrument designed to assess the main functioning problems experienced by psychiatric patients, particularly bipolar patients. It comprises 24 items that assess impairment or disability in six specific areas of functioning: autonomy, occupational functioning, cognitive functioning, financial issues, interpersonal relationships and leisure time.

Methods

101 patients with DSM-IV TR bipolar disorder and 61 healthy controls were assessed in the Bipolar Disorder Program, Hospital Clinic of Barcelona. The psychometric properties of FAST (feasibility, internal consistency, concurrent validity, discriminant validity (euthymic vs acute patients), factorial analyses, and test-retest reliability) were analysed.

Results

The internal consistency obtained was very high with a Cronbach's alpha of 0.909. A highly significant negative correlation with GAF was obtained (r = -0.903; p < 0.001) pointing to a reasonable degree of concurrent validity. Test-retest reliability analysis showed a strong correlation between the two measures carried out one week apart (ICC = 0.98; p < 0.001). The total FAST scores were lower in euthymic (18.55 ± 13.19; F = 35.43; p < 0.001) patients, as compared with manic (40.44 ± 9.15) and depressive patients (43.21 ± 13.34).

Conclusion

The FAST showed strong psychometrics properties and was able to detect differences between euthymic and acute BD patients. In addition, it is a short (6 minutes) simple interview-administered instrument, which is easy to apply and requires only a short period of time for its application.