The new DSM-5 somatic symptom disorder was introduced to improve the diagnosis of persons experiencing what used to be called somatoform disorders. So far, it is unclear whether existing self-report measures are useful to detect the new somatic symptom disorder. This study investigates the diagnostic accuracy of three self-report questionnaires that measure somatic complaints (15 item Patient Health Questionnaire [PHQ-15]) and psychological features (7-item Whiteley Index [WI-7]; Scale for Assessing Illness Behavior [SAIB]), in detecting somatic symptom disorder.
A nationally representative general population survey was performed resulting in 250 participants (minimum age = 14 years. 12.8% participation rate). Assessment took place at baseline and 12-month follow-up. Individual and combined diagnostic accuracy of the PHQ-15, WI-7, and SAIB in detecting somatic symptom disorder was evaluated using the area under the curve (AUC) of a receiver operating characteristic.
Diagnostic accuracy was adequate to good for each individual questionnaire (PHQ-15: AUC = 0.79, p < .001, 95% confidence interval [CI] = 0.73–0.85; WI-7: AUC = 0.76, p < .001, 95% CI = 0.69–0.83; SAIB: AUC = 0.77, p < .001, 95% CI = 0.71–0.83). Combining the PHQ-15 and the WI-7 slightly improved diagnostic accuracy (AUC = 0.82, p < .001, 95% CI = 0.77–0.88), as did the combination of all three questionnaires (AUC = 0.85, p < .001, 95% CI = 0.79–0.90).
The PHQ-15, WI-7, and SAIB are useful screening instruments to detect persons at risk for somatic symptom disorder, and a combination of these three instruments slightly improves diagnostic accuracy. Their use in routine care will lead to improved detection rates.
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From the Division of Clinical Psychology and Psychotherapy (Laferton, Stenzel), Psychologische Hochschule Berlin; Divisions of Clinical Psychology and Psychotherapy (Rief) and Clinical Biopsychology (Klaus, Mewes), Philipps University Marburg; Institute of Medical Psychology (Brähler), Medical School, University of Leipzig; and Department of Psychosomatic Medicine and Psychotherapy (Brähler), University Medical Center of the Johannes Gutenberg University Mainz, Germany.
Address correspondence and reprint requests to Johannes A.C. Laferton, PhD, Psychologische Hochschule Berlin, Am Köllnischen Park 2, 10179 Berlin, Germany. E-mail: email@example.com
Related editorial on pages 971–973
Received for publication March 27, 2017; revision received June 28, 2017.