Somatic symptom burden and health anxiety in the population and their correlates.

OBJECTIVE: Somatic symptom burden and health anxiety demonstrate overlapping clinical characteristics but their relationship in the general population is unclear. This study examined the association between these dimensions after adjustment for confounders and their respective correlation with outcome measures. METHODS: A randomly selected population-based sample of 3014 respondents aged 15-65 was interviewed by telephone using a structured questionnaire that included the 15-item Patient Health Questionnaire (PHQ-15), Whiteley-7, Kessler-6, Sheehan Disability Scale, socio-demographic variables and items regarding health care utilization. Respondents who scored 10 or above on PHQ-15 and 4 or above on Whiteley-5 were regarded as having high somatic symptom burden and high health anxiety respectively. RESULTS: Somatic symptom burden and health anxiety are moderately correlated after adjustment for confounders (p<.001). Both have important effects on psychological distress, functional impairment and health care utilization independent of each other (ps<.001). A considerable number of respondents (5.7%) reported both high somatic symptom burden and high health anxiety and this group showed the greatest general psychological distress, functional impairment and health care utilization. CONCLUSION: This study demonstrates the close association of somatic symptom burden and health anxiety but also their independent association with psychological distress, functional impairment and health care utilization. The findings support the concept of the DSM-5 category of somatic symptom disorder, but also demonstrate that individuals with high somatic symptom burden or high health anxiety alone may merit separate diagnoses. More sophisticated studies of the relationship between somatic symptom burden and health anxiety are needed.

Somatization and health anxiety as predictors of health care use.

OBJECTIVE: To assess whether the number of somatic symptoms and health anxiety are independent predictors of future health care use after adjusting for confounders. METHODS: In a random sample of the adult UK population, questionnaires assessed the number of somatic symptoms (Somatic Symptom Inventory), health anxiety (Whiteley Index), anxiety/depression (Hospital Anxiety and Depression Scale), the number of physical illnesses and demographic variables. The number of consultations in primary care was obtained from medical records for 1 year before and after questionnaire assessment, and negative binomial regression analyses identified predictors of consultation rate. RESULTS: The sample included 961 participants (58.0% response) with complete medical record data for 609 participants. After adjustment for consultation rate in the prior year, the predictors of subsequent consultation rate in primary care were the number of physical illnesses, off work through illness, Whiteley Index (incidence rate ratio [IRR] = 1.22, 95% confidence interval [CI] = 1.09-1.35), and the Whiteley Index-by-Somatic Symptom Inventory interaction term. Reported physical abuse predicted an increased consultation rate in women (IRR = 2.30, 95% CI = 1.08-4.90) but a reduced rate in men (IRR = 0.43, 95% CI = 0.22-0.84), interaction p = 0.003. CONCLUSIONS: These data raise the possibility that both increased health anxiety and number of bothersome somatic symptoms predict frequent medical consultations. A more complex model of predicting future health care use is needed than has been studied previously, which is potentially relevant to the current discussions of the proposed DSM-V and International Classification of Diseases, 11th Revision, diagnostic guidelines regarding complex somatic symptom disorders.

The epidemiology of multiple somatic symptoms.

BACKGROUND: The risk factors for a high total somatic symptom count are unclear; and it is not known whether total somatic symptoms count is a predictor of impaired health status. METHOD: A prospective population-based cohort study in North West England. Randomly sampled residents (1443 participants; 58% response) completed questionnaires to determine number of somatic symptoms (SSI), health status and a wide range of risk factors; 741 completed questionnaires 1 year later. We used logistic regression to identify risk factors for high SSI at follow-up and for persistently high SSI. We used ANCOVAR and multiple regression to assess whether baseline SSI predicted health status at follow-up. RESULTS: Twenty-one percent of participants scored over 25 on the Somatic Symptom Inventory (SSI) at baseline and 14% at both baseline and follow-up. Risk factors for a persistent high SSI were: fewer than 12 years of education, separated, widowed or divorced status, reported psychological abuse during childhood, co-existing medical illnesses, anxiety and depression. In multivariate analysis baseline SSI predicted health status (SF12 physical component score and health-related quality of life (EuroQol)) 12 months later. Persistent high SSI was a clinically meaningful predictor of these outcomes. CONCLUSIONS: Our data support a biopsychosocial approach to somatic symptoms rather than the dualistic approach of identifying "medically unexplained" symptoms. The risk factors for total somatic symptom count were those associated with psychiatric disorders including physical illness. A persistent high somatic symptom count provides a readily measured dimension of importance in epidemiology as a predictor of health status.

Psychiatric disorder, irritable bowel syndrome, and extra-intestinal symptoms in a population-based sample of twins.

OBJECTIVES: To determine, in a population-based sample of twin pairs, if extra-intestinal symptoms (EIS) are closely associated with both irritable bowel syndrome (IBS) and psychiatric disorders and whether such associations are explained on a genetic basis. METHODS: A random sample of twins between the ages of 44 and 64 years enrolled in the Minnesota Twins Registry completed the Modified Mayo Clinic Bowel Disease Questionnaire, a questionnaire on extra-intestinal symptoms, and the Psychiatric Diagnostic Screening Questionnaire. RESULTS: Of the 3,048 participants (51% response rate), 371 (12.2%) fulfilled Rome II criteria for IBS; 61 (16.4%) had a psychiatric disorder compared with 7.6% (n=204) of those without IBS (P<0.001). In regression analysis both IBS and psychiatric disorders were independently associated with the number of extra-intestinal symptoms (P<0.0005). Concordance rates for high EIS score were 30.0% for monozygote (MZ) twins and 16.7% in dizygote (DZ) twins (P=0.020) and the OR for concordance remained substantially higher for MZ than DZ twins after adjustment for psychiatric disorder and presence of IBS (6.82 (95% CI 4.45-10.45) and 2.71 (95% CI 1.69-4.37)). In MZ twins discordant for IBS, EIS and IBS were significantly associated (P=0.004) and psychiatric disorder and EIS were significantly associated (P=0.001). CONCLUSIONS: Extra-intestinal symptoms are independently associated with both IBS and psychiatric disorders. There is evidence that there is a genetic basis to EIS, but the association with IBS and psychiatric disorders is not primarily explained by genetic influences.

The physical and social associations of common mental disorder in a tribal population in South India.

BACKGROUND: Previous studies have shown high prevalence rates of Common Mental Disorder (CMD) in developing countries, however few have studied its relationship with physical morbidity. AIMS: To examine the association between CMD and anaemia, malnutrition and physical symptoms. METHOD: Outpatients attending a hospital for tribal people in Kerala, India were interviewed to collect information on demographic characteristics, physical symptoms and life events. They were weighed and measured and their haemoglobin concentration was measured. Associations between these data and Self Report Questionnaire (SRQ) score were examined. RESULTS: Multivariate analysis showed high SRQ score was associated with more physical symptoms, being female, no education and more life events in the past year. CONCLUSIONS: The main associations of CMD are social. The association with physical symptoms may also be socially mediated.