The reliability and validity of a screening Questionnaire for 13 DSM-IV Axis I disorders (the Psychiatric Diagnostic Screening Questionnaire) in psychiatric outpatients.

BACKGROUND: The purpose of this study was to examine the reliability and validity of a new multidimensional screening instrument for 13 DSM-IV Axis I disorders.
METHOD: The Psychiatric Diagnostic Screening Questionnaire (PDSQ) is a 90-item self-administered questionnaire that screens for 13 DSM-IV disorders in 5 areas (eating, mood, anxiety, substance use, and somatoform disorders). A consecutive series of 500 psychiatric outpatients completed the PDSQ immediately before their intake evaluation. Seventy-four patients completed the scale a second time less than a week after the initial administration, and 51 patients completed a booklet of questionnaires that included established measures of the same symptom domains assessed by the PDSQ.
RESULTS: The PDSQ subscales achieved moderate-to-high levels of internal consistency (mean Cronbach's alpha coefficient = 0.82) and test-retest reliability (mean correlation coefficient = 0.84). Subscale scores were significantly associated with blind clinical diagnoses, and individual PDSQ items correlated much more highly with their own subscale than with other subscales. The PDSQ subscales were much more highly correlated with established measures of the same symptom domain (mean correlation coefficient = 0.72) than with measures of other types of psychopathology (mean correlation = 0.17).
CONCLUSION: The PDSQ is a reliable and valid measure of multiple DSM-IV disorders that is brief enough to be incorporated into routine clinical outpatient practice without disruption, yet lengthy enough to be a psychometrically sound instrument.