Annotated Abstracts of Journal Articles
2013, 4th Quarter
Annotations by Anna Dickerman, MD and Michael Sharpe, MD, FAPM
December 2013
ANNOTATION (Dickerman & Sharpe)
The Findings: The new DSM-5 diagnosis of Somatic Symptom Disorder (SSD) has predictive validity and clinical utility, with better prediction of overall mental function at 12-month follow-up compared to DSM-IV somatoform disorder.
Strength and Weaknesses: This study had a large sample size, was a prospective study, and had a high rate of response from subjects. However, the authors only examined patients in a specialized treatment setting (an inpatient unit in Germany). Thus, the findings may not be generalizable to a broader population of patients with somatic symptom disorders. The study also used preliminary DSM-5 diagnostic criteria which had not yet been finalized.
Relevance: There has been a major shift in DSM-5 toward defining somatic symptom disorders on the basis of positive psychiatric symptoms (e.g., distress and dysfunction) rather than the absence of medical explanation for symptoms (which is inherently unreliable). This article adds to the existent body of literature suggesting that the DSM-5 criteria for SSD are indeed clinically useful and represent an improvement over the DSM-IV predecessor in terms of predictive, construct, and descriptive utility.
Objective: To compare the predictive validity and clinical utility of DSM-IV
somatoform disorders and DSM-5 Somatic Symptom Disorder (SSD) at 12-month
follow-up.
Methods: In a sample of psychosomatic inpatients (n=322, mean age=45.6 years (SD
10.0), 60.6% females) we prospectively investigated DSM-IV somatoform disorders
and the DSM-5 diagnosis of SSD plus a variety of psychological characteristics,
somatic symptom severity, and health-related quality of life at admission,
discharge, and follow-up.
Results: DSM-IV diagnoses and DSM-5 SSD similarly predicted physical functioning
at follow-up; SSD also predicted mental functioning at follow-up. Bodily
weakness, intolerance of bodily complaints, health habits, and somatic
attribution at admission were significant predictors of physical functioning at
follow-up. The change in physical functioning during inpatient therapy was a
significant predictor for the course of physical functioning until follow-up.
Conclusions: Psychological symptoms appear to be predictively valid diagnostic
criteria for the 12-month functional outcome in patients with SSD. Mental
functioning can be better predicted by the DSM-5 diagnosis than by DSM-IV
diagnoses. Not the change in single psychological features but in physical
functioning during the treatment interval predicted the change in physical
functioning until follow-up.
Tomenson B, Essau C, Jacobi F, Ladwig KH, Leiknes KA, Lieb R, et al
Br J Psychiatry 2013 Nov; 203(5):373-80
See also the related Editorial in same issue:
Sharpe M: Somatic symptoms: beyond “medically unexplained”
Br J Psychiatry 2013 Nov; 203(5):320-1
ANNOTATION (Dickerman & Sharpe)
The Finding: Total burden of somatic symptoms is a more meaningful predictor of overall health status and healthcare usage as compared to “medically unexplained” symptoms. This finding is sustained even after adjustment for potential confounders such as anxiety, depression, and general medical illness.
Strengths and Weaknesses:This multisite study had a very large total n of > 28,000. Different outcome measures were used at different sites, which is both a strength (greater generalizability) and a weakness (not able to combine or compare results from different sites). The subject population was somewhat limited from an ethnocultural standpoint. In general, severity of medical illness was not measured and presence of medical illness was not verified by a doctor or other health care practitioner. Further prospective studies are needed to replicate the findings.
Relevance: This paper provides further support for the shift in DSM-5 away from the conventional focus on lack of an underlying medical diagnosis when evaluating and treating patients with somatic symptom disorders. Somatic symptoms are associated with high prevalence of functional impairment, and management should be focused on reducing distress and dysfunction related to somatic symptoms.
Background: The diagnosis of somatisation disorder in DSM-IV was based on ‘medically unexplained’ symptoms, which is unsatisfactory.
Aims: To determine the value of a total somatic symptom score as a predictor of health status and healthcare use after adjustment for anxiety, depression and general medical illness.
Method: Data from nine population-based studies (total n = 28 377) were analysed.
Results: In all cross-sectional analyses total somatic symptom score was associated with health status and healthcare use after adjustment for confounders. In two prospective studies total somatic symptom score predicted subsequent health status. This association appeared stronger than that for medically unexplained symptoms.
Conclusions: Total somatic symptom score provides a predictor of health status and healthcare use over and above the effects of anxiety, depression and general medical illnesses.
Gierk B, Kohlmann S, Kroenke K, Spangenberg L, Zenger M, Brähler E, Löwe B
ANNOTATION (Dickerman & Sharpe)
The Finding:
The SSS-8 is a new self-report measure for somatic symptom burden with good reliability and validity.
Strengths and Limitations: This study had a large sample size. However, the findings were drawn from the general population, so the SSS-8 requires further study in patients receiving clinical care. The response rate was somewhat low (56.6%), which may limit the generalizability of the findings. The study was performed using a cross-sectional design, so longitudinal studies are needed to determine test-retest reliability, responsiveness to treatment, and “minimum clinicall important difference” (e.g., identification of which intraindividual SSS-8 score difference is clinically meaningful).
Relevance: Emerging evidence suggests that total somatic symptom burden is an important predictor of overall functional status and healthcare usage (see Publication #2). The SSS-8 is a subjective report measure that is easy to administer and may be a useful quantitative marker for overall somatic symptom burden in many medical settings. The SSS-8 may be a helpful diagnostic tool for identifying the presence of somatic symptom disorder in both clinical and research settings.
Importance: Somatic symptoms are the core features of many medical diseases, and they are used to evaluate the severity and course of illness. The 8-item Somatic Symptom Scale (SSS-8) was recently developed as a brief, patient-reported outcome measure of somatic symptom burden, but its reliability, validity, and usefulness have not yet been tested.
Objective: To investigate the reliability, validity, and severity categories as well as the reference scores of the SSS-8.
Design, Setting, and Participants: A national, representative general-population survey was performed between June 15, 2012, and July 15, 2012, in Germany, including 2510 individuals older than 13 years.
Main Outcomes and Measures: The SSS-8 mean (SD), item-total correlations, Cronbach α, factor structure, associations with measures of construct validity (Patient Health Questionnaire-2 depression scale, Generalized Anxiety Disorder-2 scale, visual analog scale for general health status, 12-month health care use), severity categories, and percentile rank reference scores.
Results: The SSS-8 had excellent item characteristics and good reliability (Cronbach α = 0.81). The factor structure reflects gastrointestinal, pain, fatigue, and cardiopulmonary aspects of the general somatic symptom burden. Somatic symptom burden as measured by the SSS-8 was significantly associated with depression (r = 0.57 [95% CI, 0.54 to 0.60]), anxiety (r = 0.55 [95% CI, 0.52 to 0.58]), general health status (r = -0.24 [95% CI, -0.28 to -0.20]), and health care use (incidence rate ratio, 1.12 [95% CI, 1.10 to 1.14]). The SSS-8 severity categories were calculated in accordance with percentile ranks: no to minimal (0-3 points), low (4-7 points), medium (8-11 points), high (12-15 points), and very high (16-32 points) somatic symptom burden. For every SSS-8 severity category increase, there was a 53% (95% CI, 44% to 63%) increase in health care visits.
Conclusions and Relevance: The SSS-8 is a reliable and valid self-report measure of somatic symptom burden. Cutoff scores identify individuals with low, medium, high, and very high somatic symptom burden.