Comparison of psychiatric screening tests in a general medical setting using ROC analysis.

Receiver operating characteristic (ROC) analysis was used to evaluate the usefulness of three self-administered screening instruments in helping primary care physicians detect anxiety and depressive disorders. This research was secondary to an investigation of hypochondriasis. The three tests were the Whitely Index (WI), the Somatosensory Amplification Scale (SAS), and the Somatic Symptom Inventory (SSI). Participating subjects were 75 patients seen in a general medical clinic and diagnosed as being free of hypochondriasis by DSM-III-R criteria. Psychiatric disorder was assessed with the Diagnostic Interview Schedule, version III-A. The three instruments delineated patients with depressive disorders versus no depressive disorders and patients with anxiety disorders versus no anxiety disorders. For depressive disorder, the areas under the curve (AUC) were 0.87, 0.75, and 0.82 for the WI, SAS, and SSI, respectively. For anxiety disorders the AUCs were 0.79, 0.76, and 0.74, respectively, for the three tests. Although the WI yielded slightly higher values, the areas under the ROC curves did not differ significantly among the three tests. Because of its relatively short length--13 items--it was concluded that the WI can be useful for screening primary care patients, both with respect to depressive and anxiety disorders.