Development of the Ghent Multidimensional Somatic Complaints Scale

Network Analysis of Persistent Somatic Symptoms in Two Clinical Patient Samples

OBJECTIVE

Previous attempts to group persistent somatic symptoms (PSSs) with factor-analytic approaches have obtained heterogeneous results. An alternative approach that seems to be more suitable is the network theory. Compared with factor analysis, which focuses on the underlying factor of symptoms, network analysis focuses on the dynamic relationships and interactions among different symptoms. The main aim of this study is to apply the network approach to examine the heterogeneous structure of PSS within two clinical samples.

METHODS

The first data set consisted of n = 254 outpatients who were part of a multicenter study. The second data set included n = 574 inpatients, both with somatoform disorders. Somatic symptom severity was assessed with the Screening of Somatoform Disorder (SOMS-7T).

RESULTS

Results indicate that there are five main symptom groups that were found in both samples: neurological, gastrointestinal, urogenital, cardiovascular, and musculoskeletal symptoms. Although patterns of symptoms with high connection to each other look quite similar in both networks, the order of the most central symptoms (e.g., symptoms with a high connection to other symptoms in the network) differs.

CONCLUSIONS

This work is the first to estimate the structure of PSS using network analysis. A next step could be first to replicate our findings before translating them into clinical practice. Second, results may be useful for generating hypotheses to be tested in future studies, and the results open new opportunities for a better understanding for etiology, prevention, and intervention research.

Systematic review of measurement properties of questionnaires measuring somatization in primary care patients

OBJECTIVE

The aim of this review is to critically appraise the evidence on measurement properties of self-report questionnaires measuring somatization in adult primary care patients and to provide recommendations about which questionnaires are most useful for this purpose.

METHODS

We assessed the methodological quality of included studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. To draw overall conclusions about the quality of the questionnaires, we conducted an evidence synthesis using predefined criteria for judging the measurement properties.

RESULTS

We found 24 articles on 9 questionnaires. Studies on the Patient Health Questionnaire-15 (PHQ-15) and the Four-Dimensional Symptom Questionnaire (4DSQ) somatization subscale prevailed and covered the broadest range of measurement properties. These questionnaires had the best internal consistency, test-retest reliability, structural validity, and construct validity. The PHQ-15 also had good criterion validity, whereas the 4DSQ somatization subscale was validated in several languages. The Bodily Distress Syndrome (BDS) checklist had good internal consistency and structural validity. Some evidence was found for good construct validity and criterion validity of the Physical Symptom Checklist (PSC-51) and good construct validity of the Symptom Check-List (SCL-90-R) somatization subscale. However, these three questionnaires were only studied in a small number of primary care studies.

CONCLUSION

Based on our findings, we recommend the use of either the PHQ-15 or 4DSQ somatization subscale for somatization in primary care. Other questionnaires, such as the BDS checklist, PSC-51 and the SCL-90-R somatization subscale show promising results but have not been studied extensively in primary care.

Redefining and assessing emotional understanding based on the componential emotion approach

This article reports on a redefinition and a new operationalisation of the construct of emotional understanding based on the componential emotion approach. Emotional understanding was redefined as the ability to understand the likely emotional processes (i.e., appraisals, action tendencies, bodily reactions, expressions, and subjective feelings) that emerge when a person encounters goal-relevant events. In all, 10 emotions were identified to represent the variability in the emotion domain. For each emotion, a scenario was constructed that typically elicits that emotion. For each scenario, participants had to rate the likelihood of five emotions, five appraisals, five action tendencies, five bodily reactions, five expressions, and five subjective feelings. The new instrument, the Components of Emotional Understanding Test–South African Student version, was administered to 132 undergraduate students from diverse cultural backgrounds. Confirmatory factor analysis confirmed the expected one-factorial structure. Emotional understanding correlated positively with verbal cognitive ability, self-report emotional intelligence, and well-being and was negatively correlated with somatic complaints. Moreover, women outscored men, and no difference was observed between respondents with Black African and White cultural backgrounds.

Somatic symptom reports in the general population: Application of a bi-factor model to the analysis of change

OBJECTIVE

To investigate the latent structure of somatic symptom reports in the general population with a bi-factor model and apply the structure to the analysis of change in reported symptoms after the emergence of an uncertain environmental health risk.

METHODS

Somatic symptoms were assessed in two general population environmental health cohorts (AMIGO, n=14,829 & POWER, n=951) using the somatization scale of the four-dimensional symptom questionnaire (4DSQ-S). Exploratory bi-factor analysis was used to determine the factor structure in the AMIGO cohort. Multi-group and longitudinal models were applied to assess measurement invariance. For a subsample of residents living close to a newly introduced power line (n=224), we compared a uni- and multidimensional method for the analysis of change in reported symptoms after the power line was put into operation.

RESULTS

We found a good fit (RMSEA=0.03, CFI=0.98) for a bi-factor model with one general and three symptom specific factors (musculoskeletal, gastrointestinal, cardiopulmonary). The latent structure was found to be invariant between cohorts and over time. A significant increase (p<.05) was found only for musculoskeletal and gastrointestinal symptoms after the power line was put into operation.

CONCLUSIONS

In our study we found that a bi-factor structure of somatic symptoms reports was equivalent between cohorts and over time. Our findings suggest that taking this structure into account can lead to a more informative interpretation of a change in symptom reports compared to a unidimensional approach.

Development of an online library of patient-reported outcome measures in gastroenterology: the GI-PRO database

OBJECTIVES

Because gastrointestinal (GI) illnesses can cause physical, emotional, and social distress, patient-reported outcomes (PROs) are used to guide clinical decision making, conduct research, and seek drug approval. It is important to develop a mechanism for identifying, categorizing, and evaluating the over 100 GI PROs that exist. Here we describe a new, National Institutes of Health (NIH)-supported, online PRO clearinghouse-the GI-PRO database.

METHODS

Using a protocol developed by the NIH Patient-Reported Outcome Measurement Information System (PROMIS(®)), we performed a systematic review to identify English-language GI PROs. We abstracted PRO items and developed an online searchable item database. We categorized symptoms into content "bins" to evaluate a framework for GI symptom reporting. Finally, we assigned a score for the methodological quality of each PRO represented in the published literature (0-20 range; higher indicates better).

RESULTS

We reviewed 15,697 titles (κ>0.6 for title and abstract selection), from which we identified 126 PROs. Review of the PROs revealed eight GI symptom "bins": (i) abdominal pain, (ii) bloat/gas, (iii) diarrhea, (iv) constipation, (v) bowel incontinence/soilage, (vi) heartburn/reflux, (vii) swallowing, and (viii) nausea/vomiting. In addition to these symptoms, the PROs covered four psychosocial domains: (i) behaviors, (ii) cognitions, (iii) emotions, and (iv) psychosocial impact. The quality scores were generally low (mean 8.88 ± 4.19; 0 (min)-20 (max). In addition, 51% did not include patient input in developing the PRO, and 41% provided no information on score interpretation.

CONCLUSIONS

GI PROs cover a wide range of biopsychosocial symptoms. Although plentiful, GI PROs are limited by low methodological quality. Our online PRO library (www.researchcore.org/gipro/) can help in selecting PROs for clinical and research purposes.

Measurement and assessment of somatic symptoms

Somatic symptoms are common presentations in health settings. They can manifest as symptoms of another underlying mental disorder or be termed as medically unexplained. When they are medically unexplained they are invariably subsumed under the diagnostic categories of somatoform disorders. They are associated with interference in functioning, poor quality of life and are burdensome on health resources. The measurement of these symptoms is essential for understanding the individual and planning treatment. There are various instruments that have somatic symptoms measurement in their items. The tools have included somatic symptoms measurement in measuring general psychopathology, somatic symptoms as part of anxiety and depression, somatic symptoms specifically, and as a screening instrument for somatoform disorders. The advantages and disadvantages of common measures have been discussed. It appears that no one measure fulfils the essential criteria of an ideal measure for somatic symptoms. The measures of somatic symptoms should also be culturally sensitive and serve diagnostic, prognostic and heuristic purposes. These aspects are highlighted in the review.

Somatic complaint differences between Turkish immigrants and Belgians: do all roads lead to Rome?

OBJECTIVE

Turkish immigrants have been found to report more somatic complaints compared to western majority groups. The present study investigates the combination of two cultural explanations (somatization versus psychologization and emotion mediation) with two acculturative explanations (acculturative stress versus acculturative transition) to explain these differences.

DESIGN

In total, 144 Turkish immigrants, 353 Belgian majority members, and 222 Turkish majority members were asked to report the last three emotional episodes they encountered and to rate them on 24 emotion terms and 17 somatic sensations.

RESULTS

Turkish majorities scored higher on all somatic factors, anxiety-sadness, and self-conscious emotions followed by Turkish immigrants and Belgian majorities. Furthermore, path analysis showed (partial) mediation effects of anxiety-sadness and self-conscious factors on the differences in the somatic factors between Belgian and Turkish majorities.

CONCLUSION

These results indicate that the somatic differences do not result from a trade-off between somatization and psychologization, but that emotions mediate differences in somatic processes to a large extent. It was also found that differences between Turkish immigrants and Belgian majority members are to be attributed to acculturative transition, rather than to acculturative stress.