A self-report scale to help make psychiatric diagnoses - The psychiatric diagnostic screening questionnaire

Background: The Psychiatric Diagnostic Screening Questionnaire (PDSQ) is a brief, psychometrically strong, self-report scale designed to screen for th e most common DSM-IV Axis I disorders encountered in outpatient mental heal th settings. In the present report, we describe the diagnostic performance (sensitivity, specificity, and positive and negative predictive values) of the PDSQ in an outpatient setting. Methods: Six hundred thirty psychiatric outpatients presenting for treatmen t were evaluated with the Structured Clinical Interview for DSM-IV after co mpleting the PDSQ. Patients arrived approximately 20 minutes before the sch eduled time of the appointment to complete the scale. Diagnostic raters wer e blind to responses on the scale. Results: The PDSQ's subscales' diagnostic performance varied in a predictab le manner according to the cutoff score-as the threshold for case identific ation increased, subscale sensitivity decreased and specificity increased. Mean subscale sensitivities of 80%, 85%, and 90% resulted in mean subscale specificities of 78%, 73%, and 66%, respectively, and negative predictive v alues of 95%, 96%, and 97%. Receiver operating curves were determined for e ach subscale and all areas under the curve were significant. Conclusions: The PDSQ is a diagnostic aid designed to be used in clinical p ractice to facilitate the efficiency of conducting initial diagnostic evalu ations. From a clinical perspective, it is most important that a diagnostic aid have good sensitivity, so that most cases are detected, and high negat ive predictive value, so that most noncases on the measure are indeed nonca ses. Our results indicate that most of the PDSQ subscales were able to achi eve this goal.