Multiple measures of patient functioning exist, but may not always help to understand the impact on the patient1

Key message: Although many measures of functioning exist, little is known about how these measures help to understand the impact of functional impairment.^{[Wilson C et al., 2016]}

• To comprehensively evaluate functional outcome in schizophrenia, a combination of performance-based and other assessment modalities may be required.^{[McKibbin et al., 2004]}

Background
Global Assessment of Functioning (GAF).^{[Robertson et al., 2013]}

• The GAF is a subjective measure based on a clinician’s opinion of a patient’s level of functioning and has been found to be a reliable and valid tool.
• Impairments in psychological, social and occupational/school functioning are considered, but those related to physical or environmental limitations are not.
• The clinical rated scale ranges from 0 (inadequate information) to 100 (superior functioning).

Personal and Social Performance scale (PSP).^{[Nasrallah et al., 2008]}

• The PSP was developed through focus groups and reliability studies.
• 27 different areas of personal and social dysfunction were identified by focus groups and these were incorporated into four domains (“socially useful activities”, “personal and social relationships”, “self-care”, and “disturbing and aggressive behaviors”).
• PSP provides an overall rating score from 1 to 100, with higher scores representing better personal and social functioning.

University of California San Diego Performance-Based Skills Assessment (UPSA).^{[Patterson et al., 2001]}

• The UPSA is a performance-based measure of capacity to perform everyday functioning.
• Patient performance in 5 domains is assessed (Household Chores; Communication; Finance; Transportation; and Planning Recreational Activities).
• The total time required to complete the UPSA is ~30 minutes.
• Total scores for each subscale are calculated by transforming raw scores into a 0–10 scale, yielding comparable scores on each scale. Each score is multiplied by 2 to give a 100-point summary score.

References:
Wilson C, et al. Early Interv Psychiatry. 2016; 10(1): 81–7.

Robertson DA, et al. Schizophr Res. 2013; 146(1–3): 363–5.

Nasrallah H, et al. Psychiatry Res. 2008; 161(2): 213–24.

Patterson TL, et al. Schizophr Bull. 2001; 27(2): 235–45.

McKibbin CL, et al. Schizophr Res. 2004; 72(1): 53–67.