Psychometric properties of a performance-based measurement of functional capacity, the UCSD Performance-based Skills Assessment - Brief version.

The UCSD Performance-based Skills Assessment - Brief version (UPSA-B) describes the functions of patients without negative influences of environmental factors such as unemployment or shortage in housing. The aim of the present study is to further explore the psychometric properties of the UPSA-B as well as to ensure that the Swedish version can be used in clinical practice and for research purposes. Participants were 211 patients, 135 men and 76 women, diagnosed with schizophrenia, schizoaffective disorder, or delusional disorder. Results indicate that the UPSA-B is a reliable instrument with good psychometric properties regarding validity and reliability. The instrument also had a capacity to reveal differences between various patient groups, both diagnostic groups and groups based on remission status. The conclusion drawn is that the UPSA-B is a valuable instrument that could be used in future cross-national studies to describe the level of functioning for patients with schizophrenia and other psychotic illnesses.