Self-reported cognitive and everyday functioning in persons with psychosis: the Patient Perception of Functioning Scale.
This study examined the reliability and validity of a brief, face-valid self-report measure designed to assess subjective judgments of functioning. The Patient Perception of Functioning Scale (PPFS) is a 6-item scale with ratings for both community functioning and cognition.


METHODS
Sixty-eight subjects with psychotic disorders were recruited to complete the PPFS on 2 occasions and to complete a battery of neurocognitive tests. Objective ratings of overall illness severity (Clinical Global Impression), illness severity (Global Assessment of Functioning), and functioning (Social and Occupational Functioning Assessment Scale and Role Functioning Scale) were also obtained.


RESULTS
The internal consistency and test-retest correlation coefficients revealed that the PPFS possesses good reliability characteristics. The PPFS did not show relationships to demographic, historical, or illness-related variables such as diagnosis or length of illness. The PPFS did show significant associations with several dimensions of community functioning. However, no significant associations were found with neurocognitive measures or clinical status.


CONCLUSIONS
In populations with psychotic disorders, self-reported ratings of community function and cognition may converge less with objective cognitive measures than with objective ratings of everyday functioning. Several factors inherent to self-report methodology may have contributed to the poor convergent validity results. Theoretical underpinnings and operationalization of the underlying constructs of some neuropsychological instruments may not closely match how patients conceptualize those constructs.
Ehmann
Thomas S
TS
Early Psychosis Intervention Program c/o Peace Arch Hospital, 15521 Russell Avenue, White Rock, BC, Canada V4B 2R4. tomehmann@yahoo.com
Goldman
Robert
R
Yager
Jodi
J
Xu
Yikang
Y
MacEwan
G W
GW
D000328:Adult; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000523:psychology*; D015203:Reproducibility of Results; D012647:Self-Assessment; D012720:Severity of Illness Index