Assessing somatic symptom burden

A psychometric comparison of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8)

Benjamin Gierk, Sebastian Kohlmann, Anne Toussaint, Inka Wahl, Christian A. Brünahl, Alexandra M. Murray, Bernd Löwe

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    Objective: The Patient Health Questionnaire-15 (PHQ-15) is a frequently used questionnaire to assess somatic symptom burden. Recently, the Somatic Symptom Scale-8 (SSS-8) has been published as a short version of the PHQ-15. This study examines whether the instruments' psychometric properties and estimates of symptom burden are comparable. 

    Methods: Psychosomatic outpatients (N= 131) completed the PHQ-15, the SSS-8 and other questionnaires (PHQ-9, GAD-7, WI-7, SF-12). Item characteristics and measures of reliability, validity, and symptom severity were determined and compared. 

    Results: The reliabilities of the PHQ-15 and SSS-8 were α= 0.80 and α= 0.76, respectively and both scales were highly correlated (r= 0.83). The item characteristics were comparable. Both instruments showed the same pattern of correlations with measures of depression, anxiety, health anxiety and health-related quality of life (r= 0.32 to 0.61). On both scales a 1-point increase was associated with a 3% increase in health care use. The percentile distributions of the PHQ-15 and the SSS-8 were similar. Using the same thresholds for somatic symptom severity (5, 10, and 15 points), both instruments identified nearly identical subgroups of patients with respect to health related quality of life. 

    Conclusion: The PHQ-15 and the SSS-8 showed similar reliability and validity but the comparability of severity classifications needs further evaluation in other populations. Until then we recommend the use of the previously established thresholds. Overall, the SSS-8 performed well as a short version of the PHQ-15 which makes it preferable for assessment in time restricted settings.

    Original languageEnglish
    Pages (from-to)352-355
    Number of pages4
    JournalJournal of Psychosomatic Research
    Volume78
    Issue number4
    DOIs
    Publication statusPublished - Apr 2015

    Fingerprint

    Psychometrics
    Health
    Reproducibility of Results
    Anxiety
    Quality of Life
    Surveys and Questionnaires
    Medically Unexplained Symptoms
    Outpatients
    Depression
    Delivery of Health Care
    Population

    Cite this

    Gierk, Benjamin ; Kohlmann, Sebastian ; Toussaint, Anne ; Wahl, Inka ; Brünahl, Christian A. ; Murray, Alexandra M. ; Löwe, Bernd. / Assessing somatic symptom burden : A psychometric comparison of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8). In: Journal of Psychosomatic Research. 2015 ; Vol. 78, No. 4. pp. 352-355.
    @article{378919cf35724c6e80cac1c43ca73261,
    title = "Assessing somatic symptom burden: A psychometric comparison of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8)",
    abstract = "Objective: The Patient Health Questionnaire-15 (PHQ-15) is a frequently used questionnaire to assess somatic symptom burden. Recently, the Somatic Symptom Scale-8 (SSS-8) has been published as a short version of the PHQ-15. This study examines whether the instruments' psychometric properties and estimates of symptom burden are comparable. Methods: Psychosomatic outpatients (N= 131) completed the PHQ-15, the SSS-8 and other questionnaires (PHQ-9, GAD-7, WI-7, SF-12). Item characteristics and measures of reliability, validity, and symptom severity were determined and compared. Results: The reliabilities of the PHQ-15 and SSS-8 were α= 0.80 and α= 0.76, respectively and both scales were highly correlated (r= 0.83). The item characteristics were comparable. Both instruments showed the same pattern of correlations with measures of depression, anxiety, health anxiety and health-related quality of life (r= 0.32 to 0.61). On both scales a 1-point increase was associated with a 3{\%} increase in health care use. The percentile distributions of the PHQ-15 and the SSS-8 were similar. Using the same thresholds for somatic symptom severity (5, 10, and 15 points), both instruments identified nearly identical subgroups of patients with respect to health related quality of life. Conclusion: The PHQ-15 and the SSS-8 showed similar reliability and validity but the comparability of severity classifications needs further evaluation in other populations. Until then we recommend the use of the previously established thresholds. Overall, the SSS-8 performed well as a short version of the PHQ-15 which makes it preferable for assessment in time restricted settings.",
    keywords = "PHQ-15, Psychometrics, Somatic symptom burden, Somatization, SSS-8",
    author = "Benjamin Gierk and Sebastian Kohlmann and Anne Toussaint and Inka Wahl and Br{\"u}nahl, {Christian A.} and Murray, {Alexandra M.} and Bernd L{\"o}we",
    year = "2015",
    month = "4",
    doi = "10.1016/j.jpsychores.2014.11.006",
    language = "English",
    volume = "78",
    pages = "352--355",
    journal = "Journal of Psychosomatic Research",
    issn = "0022-3999",
    publisher = "Elsevier",
    number = "4",

    }

    Assessing somatic symptom burden : A psychometric comparison of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8). / Gierk, Benjamin; Kohlmann, Sebastian; Toussaint, Anne; Wahl, Inka; Brünahl, Christian A.; Murray, Alexandra M.; Löwe, Bernd.

    In: Journal of Psychosomatic Research, Vol. 78, No. 4, 04.2015, p. 352-355.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Assessing somatic symptom burden

    T2 - A psychometric comparison of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8)

    AU - Gierk, Benjamin

    AU - Kohlmann, Sebastian

    AU - Toussaint, Anne

    AU - Wahl, Inka

    AU - Brünahl, Christian A.

    AU - Murray, Alexandra M.

    AU - Löwe, Bernd

    PY - 2015/4

    Y1 - 2015/4

    N2 - Objective: The Patient Health Questionnaire-15 (PHQ-15) is a frequently used questionnaire to assess somatic symptom burden. Recently, the Somatic Symptom Scale-8 (SSS-8) has been published as a short version of the PHQ-15. This study examines whether the instruments' psychometric properties and estimates of symptom burden are comparable. Methods: Psychosomatic outpatients (N= 131) completed the PHQ-15, the SSS-8 and other questionnaires (PHQ-9, GAD-7, WI-7, SF-12). Item characteristics and measures of reliability, validity, and symptom severity were determined and compared. Results: The reliabilities of the PHQ-15 and SSS-8 were α= 0.80 and α= 0.76, respectively and both scales were highly correlated (r= 0.83). The item characteristics were comparable. Both instruments showed the same pattern of correlations with measures of depression, anxiety, health anxiety and health-related quality of life (r= 0.32 to 0.61). On both scales a 1-point increase was associated with a 3% increase in health care use. The percentile distributions of the PHQ-15 and the SSS-8 were similar. Using the same thresholds for somatic symptom severity (5, 10, and 15 points), both instruments identified nearly identical subgroups of patients with respect to health related quality of life. Conclusion: The PHQ-15 and the SSS-8 showed similar reliability and validity but the comparability of severity classifications needs further evaluation in other populations. Until then we recommend the use of the previously established thresholds. Overall, the SSS-8 performed well as a short version of the PHQ-15 which makes it preferable for assessment in time restricted settings.

    AB - Objective: The Patient Health Questionnaire-15 (PHQ-15) is a frequently used questionnaire to assess somatic symptom burden. Recently, the Somatic Symptom Scale-8 (SSS-8) has been published as a short version of the PHQ-15. This study examines whether the instruments' psychometric properties and estimates of symptom burden are comparable. Methods: Psychosomatic outpatients (N= 131) completed the PHQ-15, the SSS-8 and other questionnaires (PHQ-9, GAD-7, WI-7, SF-12). Item characteristics and measures of reliability, validity, and symptom severity were determined and compared. Results: The reliabilities of the PHQ-15 and SSS-8 were α= 0.80 and α= 0.76, respectively and both scales were highly correlated (r= 0.83). The item characteristics were comparable. Both instruments showed the same pattern of correlations with measures of depression, anxiety, health anxiety and health-related quality of life (r= 0.32 to 0.61). On both scales a 1-point increase was associated with a 3% increase in health care use. The percentile distributions of the PHQ-15 and the SSS-8 were similar. Using the same thresholds for somatic symptom severity (5, 10, and 15 points), both instruments identified nearly identical subgroups of patients with respect to health related quality of life. Conclusion: The PHQ-15 and the SSS-8 showed similar reliability and validity but the comparability of severity classifications needs further evaluation in other populations. Until then we recommend the use of the previously established thresholds. Overall, the SSS-8 performed well as a short version of the PHQ-15 which makes it preferable for assessment in time restricted settings.

    KW - PHQ-15

    KW - Psychometrics

    KW - Somatic symptom burden

    KW - Somatization

    KW - SSS-8

    UR - http://www.scopus.com/inward/record.url?scp=84925218391&partnerID=8YFLogxK

    U2 - 10.1016/j.jpsychores.2014.11.006

    DO - 10.1016/j.jpsychores.2014.11.006

    M3 - Article

    VL - 78

    SP - 352

    EP - 355

    JO - Journal of Psychosomatic Research

    JF - Journal of Psychosomatic Research

    SN - 0022-3999

    IS - 4

    ER -