Psychometric evaluation of the Work Readiness Questionnaire in schizophrenia.

OBJECTIVE/INTRODUCTION: Unemployment can negatively impact quality of life among patients with schizophrenia. Employment status depends on ability, opportunity, education, and cultural influences. A clinician-rated scale of work readiness, independent of current work status, can be a valuable assessment tool. A series of studies were conducted to create and validate a Work Readiness Questionnaire (WoRQ) for clinicians to assess patient ability to engage in socially useful activity, independent of work availability. METHODS: Content validity, test-retest and inter-rater reliability, and construct validity were evaluated in three separate studies. RESULTS: Content validity was supported. Cronbach's α was 0.91, in the excellent range. Clinicians endorsed WoRQ concepts, including treatment adherence, physical appearance, social competence, and symptom control. The final readiness decision showed good test-retest reliability and moderate inter-rater reliability. Work readiness was associated with higher function and lower levels of negative symptoms. Low positive and high negative predictive values confirmed the concept validity. DISCUSSION: The WoRQ has suitable psychometric properties for use in a clinical trial for patients with a broad range of symptom severity. The scale may be applicable to assess therapeutic interventions. It is not intended to assess eligibility for supported work interventions. CONCLUSIONS: The WoRQ is suitable for use in schizophrenia clinical trials to assess patient work functional potential.

Reliability, validity and ability to detect change of the PANSS negative symptom factor score in outpatients with schizophrenia on select antipsychotics and with prominent negative or disorganized thought symptoms.

The PANSS is a valid instrument assessing schizophrenia symptom severity. Analyses have identified a five-factor solution. The negative symptom factor (NSFS) is robust, having been replicated in multiple analyses. The score has superior content validity versus the negative subscale. Aspects of validity in patients with predominant negative symptoms have yet to be established. The present data are from a Phase IIb study of add-on bitopertin therapy in schizophrenia outpatients with prominent negative or disorganized thought symptoms treated with antipsychotics. Analyses were conducted to evaluate reliability, validity and sensitivity to change. Test-retest screening to baseline was high (ICC=0.93). This was maintained in-study, for patients with no change in CGI negative symptom severity (CGI-S-N). Internal consistency at baseline was adequate (α=0.71) and increased at later assessments. Pearson correlation at baseline showed a good association between NSFS and CGI-S-N (0.63), but not overall CGI-S (0.31). Association with PSP at baseline was moderate (-0.39) and for change at Week eight good (-0.65). NSFS responders (≥20% improvement) at Week eight showed a significant improvement in function. The analyses demonstrated reliability, validity and ability to detect change of the NSFS, in schizophrenia patients with prominent negative or disorganized thought symptoms.