Anne Toussaint1, Kurt Kroenke2, Fitsum Baye3, Spencer Lourens4. 1. Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Hamburg-Eppendorf and Schön Klinik Hamburg Eilbek, Hamburg, Germany. Electronic address: a.toussaint@uke.de. 2. VA HSR&D Center for Health Information and Communication, Roudebush VA Medical Center, Indianapolis, IN, United States; Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States; Regenstrief Institute, Inc., Indianapolis, IN, United States. Electronic address: kkroenke@regenstrief.org. 3. Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN, United States. Electronic address: fbaye@iu.edu. 4. Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN, United States. Electronic address: slourens@iu.edu.
Abstract
PURPOSE: The Patient Health Questionnaire - 15 (PHQ-15) and the Somatic Symptom Scale - 8 (SSS-8) are self-report measures which assess somatic symptom burden. The present study investigates whether the two measures are comparable in terms of their psychometric properties and estimates of symptom burden. METHOD:Item characteristics, reliability, symptom severity and construct validity with regard to other relevant psychological, health-related quality of life and disability measures were compared for the PHQ-15m and the SSS-8 in 294 primary care patients who participated in a randomized comparative effectiveness trial targeting pain and mood symptoms. RESULTS: The reliabilities of the PHQ-15m and the SSS-8 were α=0.66 and α=0.72, respectively. Both measures were highly correlated (r=0.79). All item characteristics were comparable and both instruments showed the same pattern of correlations with instruments measuring depression, anxiety, pain, quality of life and impairment (r=0.25 to 0.53). A 1-point score increase (worsening of somatic symptoms) on either instrument resulted in a 3.7% to 3.9% increase in the number of disability days reported for the last four weeks. Using the same severity thresholds (5: low, 10: medium, 15: high), both measures identified nearly identical subgroups of patients with regard to health-related quality of life and disability. CONCLUSION: The PHQ-15m and the SSS-8 are comparable measures in terms of reliability and validity and severity classifications. These findings are in line with previous results and support the use of the SSS-8 as a valuable and short alternative to the original PHQ-15 in settings with limited assessment time.
RCT Entities:
PURPOSE: The Patient Health Questionnaire - 15 (PHQ-15) and the Somatic Symptom Scale - 8 (SSS-8) are self-report measures which assess somatic symptom burden. The present study investigates whether the two measures are comparable in terms of their psychometric properties and estimates of symptom burden. METHOD: Item characteristics, reliability, symptom severity and construct validity with regard to other relevant psychological, health-related quality of life and disability measures were compared for the PHQ-15m and the SSS-8 in 294 primary care patients who participated in a randomized comparative effectiveness trial targeting pain and mood symptoms. RESULTS: The reliabilities of the PHQ-15m and the SSS-8 were α=0.66 and α=0.72, respectively. Both measures were highly correlated (r=0.79). All item characteristics were comparable and both instruments showed the same pattern of correlations with instruments measuring depression, anxiety, pain, quality of life and impairment (r=0.25 to 0.53). A 1-point score increase (worsening of somatic symptoms) on either instrument resulted in a 3.7% to 3.9% increase in the number of disability days reported for the last four weeks. Using the same severity thresholds (5: low, 10: medium, 15: high), both measures identified nearly identical subgroups of patients with regard to health-related quality of life and disability. CONCLUSION: The PHQ-15m and the SSS-8 are comparable measures in terms of reliability and validity and severity classifications. These findings are in line with previous results and support the use of the SSS-8 as a valuable and short alternative to the original PHQ-15 in settings with limited assessment time.
Authors: Lauren K Robinson; Laura Sterling; Joel Jackson; Eric Gentry; Fabiana Araujo; Cynthia LaFond; Kristen C Jacobson; Royce Lee Journal: SAGE Open Nurs Date: 2022-05-10
Authors: Marie Weinreich Petersen; Marianne Rosendal; Eva Ørnbøl; Per Fink; Torben Jørgensen; Thomas Meinertz Dantoft; Andreas Schröder Journal: BMJ Open Date: 2020-12-10 Impact factor: 2.692
Authors: Jonna Hybelius; Anton Gustavsson; Sandra Af Winklerfelt Hammarberg; Eva Toth-Pal; Robert Johansson; Brjánn Ljótsson; Erland Axelsson Journal: Pilot Feasibility Stud Date: 2022-07-19