DIFFERENTIAL-DIAGNOSIS OF PALPITATIONS - PRELIMINARY DEVELOPMENT OF ASCREENING INSTRUMENT

Objective: To develop a self-report screening instrument to assist in the differential diagnosis of medical outpatients complaining of palpi tations. Design: Patients completed self-report questionnaires assessi ng somatization, cardiac symptoms, and hypochondriacal concerns about health. Principal components analysis was performed to identify a subs et of questions that could be used to distinguish patients with palpit ations who have panic disorder from those with palpitations who do not have panic disorder. Patients: Sixty-seven medical outpatients referr ed for Holter monitoring because of a complaint of palpitations. Main Outcome Measures: Patients with Palpitations were classified into 2 gr oups, those with and those without current panic disorder (established with a structured, diagnostic interview). The sensitivity, specificit y, and posttest probability of the screening instrument were determine d. Results: A reliable, stable, 10-item instrument was derived. It see ms to tap diffuse, vague, or generalized somatic complaints and worry about physical illness. With the use of a criterion cutoff score of 21 , this instrument had a sensitivity of 0.81, a specificity of 0.80, an d a posttest probability of .57 in detecting current panic disorder in patients with palpitations. Conclusion: A psychometrically sound and brief self-report instrument was developed to assist in the differenti al diagnosis of palpitations. It can be used to identify patients whos e symptoms are more likely to result from panic disorder and in whom a mbulatory monitoring might be deferred.