TY - JOUR
T1 - Head-to-head comparison of somatic symptom scales
T2 - The Patient Health Questionnaire (PHQ-15) and the somatization scale of the Four-Dimensional Symptom Questionnaire (4DSQ-S)
AU - Terluin, Berend
AU - Barends, Hieke
AU - van der Horst, Henriëtte E
AU - Dekker, Joost
AU - van der Wouden, Johannes C
N1 - Funding Information: This work was supported by grants of ZonMw (The Netherlands Organization for Health Research and Development), the SBOH (the Dutch employer of GP trainees) and the Stoffels-Hornstra Foundation , a non-profit organization supporting primary care research in the fields of cancer, brain diseases, cardiovascular diseases and ophthalmological diseases. The funding sources had no role in the design, analyses and interpretation of our study. Publisher Copyright: © 2022 The Author(s)
PY - 2022/11
Y1 - 2022/11
N2 - OBJECTIVE: The goal of this study was to compare the 15-item Patient Health Questionnaire (PHQ-15) and the somatization subscale of the Four-Dimensional Symptoms Questionnaire (4DSQ-S) with respect to their latent structure and reliability, and to examine whether their scores are affected by age and gender, and whether the scales measure the same construct(s).METHODS: The study population consisted of individuals with a tendency to experience persistent somatic symptoms, recruited in multiple healthcare settings, who completed the PHQ-15 and 4DSQ-S concurrently. We analyzed the scales' latent factor structure using confirmatory factor analysis (CFA), the scales' reliability, and differential item functioning (DIF) due to age and gender. We performed a head-to-head comparison by fitting structural equation models of the questionnaires' factors.RESULTS: We included 234 participants. CFA showed that both questionnaires fitted a bifactor model with a general factor and four specific factors, three of which (labeled "musculoskeletal", "gastrointestinal", and "cardiopulmonary") were substantively similar. Both scales were essentially unidimensional. The reliability of the PHQ-15 and 4DSQ-S was equally high (omega 0.933 and 0.942, respectively). DIF-analysis showed minor DIF for age in one item of each questionnaire, with negligible impact on the scale score. Head-to-head comparison showed that the PHQ-15 and 4DSQ-S measured the same constructs. We present PHQ-15 - 4DSQ-S cross-walk tables.CONCLUSIONS: Both questionnaires mainly measure a single somatic symptom burden dimension of which all symptoms (covered by the questionnaires) are adequate indicators. They do so equally accurately and they behave the same across gender and age categories.
AB - OBJECTIVE: The goal of this study was to compare the 15-item Patient Health Questionnaire (PHQ-15) and the somatization subscale of the Four-Dimensional Symptoms Questionnaire (4DSQ-S) with respect to their latent structure and reliability, and to examine whether their scores are affected by age and gender, and whether the scales measure the same construct(s).METHODS: The study population consisted of individuals with a tendency to experience persistent somatic symptoms, recruited in multiple healthcare settings, who completed the PHQ-15 and 4DSQ-S concurrently. We analyzed the scales' latent factor structure using confirmatory factor analysis (CFA), the scales' reliability, and differential item functioning (DIF) due to age and gender. We performed a head-to-head comparison by fitting structural equation models of the questionnaires' factors.RESULTS: We included 234 participants. CFA showed that both questionnaires fitted a bifactor model with a general factor and four specific factors, three of which (labeled "musculoskeletal", "gastrointestinal", and "cardiopulmonary") were substantively similar. Both scales were essentially unidimensional. The reliability of the PHQ-15 and 4DSQ-S was equally high (omega 0.933 and 0.942, respectively). DIF-analysis showed minor DIF for age in one item of each questionnaire, with negligible impact on the scale score. Head-to-head comparison showed that the PHQ-15 and 4DSQ-S measured the same constructs. We present PHQ-15 - 4DSQ-S cross-walk tables.CONCLUSIONS: Both questionnaires mainly measure a single somatic symptom burden dimension of which all symptoms (covered by the questionnaires) are adequate indicators. They do so equally accurately and they behave the same across gender and age categories.
KW - Anxiety/diagnosis
KW - Depression/diagnosis
KW - Humans
KW - Medically Unexplained Symptoms
KW - Patient Health Questionnaire
KW - Psychometrics/methods
KW - Reproducibility of Results
KW - Surveys and Questionnaires
UR - http://www.scopus.com/inward/record.url?scp=85138582631&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.jpsychores.2022.111031
DO - https://doi.org/10.1016/j.jpsychores.2022.111031
M3 - Article
C2 - 36156343
SN - 0022-3999
VL - 162
SP - 1
EP - 9
JO - Journal of psychosomatic research
JF - Journal of psychosomatic research
M1 - 111031
ER -