Somatic Symptoms in the German General Population from 1975 to 2013

Multiple physical symptoms and coping strategies over the last decade - Knowledge from two Danish population-based cross-sectional studies in 2012 and 2022

OBJECTIVE

To compare the prevalence of multiple physical symptoms, coping scores, and associations between multiple physical symptoms and coping in two population-based surveys within a 10-year interval.

METHODS

A nationwide study on symptoms and healthcare-seeking, the Danish Symptom Cohort, was carried out in 2012 and repeated in 2022. For each survey, 100,000 randomly selected individuals were invited, and individuals aged 20-64 years were eligible for inclusion. Multiple physical symptoms were identified using the 25-item Bodily Distress Syndrome checklist, and coping was assessed with the Brief Approach/Avoidance Coping Questionnaire. Statistical analyses included multinomial and logistic regressions.

RESULTS

A total of 35,877 were included in 2012 and 18,330 in 2022. Overall, 35.1% reported multiple physical symptoms in 2022 compared with 23.8% in 2012. The mean sum score for approach was lower in 2022 than in 2012 with a statistically significant mean difference of -1.27 (Cohen's d = -0.34), while diversion and resignation scores were significantly higher in 2022 with mean differences of 0.34 (Cohen's d = 0.11) and 0.52 (Cohen's d = 0.17), respectively. Regression analyses showed that lower approach scores and higher diversion and resignation scores were associated with an increased probability of having multiple physical symptoms in 2022, thereby confirming the results from 2012.

CONCLUSION

Over the decade, symptom reporting may have increased while coping strategies may have changed towards a slightly higher use of avoidance and lower use of approach. It seems relevant to identify modifiable contributing factors in society to prevent an acceleration of symptom reporting and avoidant behavior.

Revisiting the symptom iceberg based on the Danish symptom cohort - Symptom experiences and healthcare-seeking behaviour in the general Danish population in 2022

Introduction

Healthcare-seeking behaviour may change over time, and some groups are more likely to avoid relevant help seeking, which possibly contributes to social inequity in health. Thus, we developed an expansion of and follow-up to the Danish Symptom Cohort (DaSC) from 2012 and formed the DaSC II, which encompassed a population-based questionnaire study investigating symptoms and healthcare-seeking behaviour. In this paper, we describe the conceptual framework, development and content validity of the questionnaire and a responder analysis of the participants in the DaSC II. We present the symptom iceberg in the Danish general population by estimating the prevalence of symptoms and proportion of contacts to general practitioners (GPs) in 2022. Moreover, we discuss differences in healthcare-seeking behaviour with reference to the 2012 DaSC.

Methods

100,000 randomly selected Danish citizens aged ≥20 years, along with the 44,713 respondents from the 2012 cohort, were invited to participate in a survey. The questionnaire was pilot and field tested prior to distribution. Descriptive statistics were used to estimate symptom prevalence and proportion of GP contacts, and to execute the respondent analysis.

Results

Nine out of ten respondents reported at least one symptom within the preceding four weeks and reported an average of 4.6 symptoms. One in four symptoms were presented to a GP. The highest proportion of GP contacts was found for haematuria (63.3 %) and shortness of breath (51.8 %). For several symptoms, differences between the sexes were found in relation to both prevalence and GP contacts. The proportion of GP contacts was higher in 2022 than in 2012 and was most pronounced for general, frequently experienced symptoms and to a lesser extent for cancer alarm symptoms.

Conclusion

Many symptoms go unreported, which may delay relevant diagnosis; more research on certain symptom categories and population subgroups is needed. Future studies based on the DaSC II form a basis for interventions targeting symptom awareness, healthcare-seeking behaviour and social equity in society and health.

Intersectional inequalities in somatic symptom severity in the adult population in Germany found within the SOMA.SOC study

Somatic symptoms are common in a wide range of medical conditions. In severe cases, they are associated with high individual and economic burden. To explore social inequalities in somatic symptom severity (SSS) and to identify social groups with highest SSS, we applied an intersectional research approach. Analyses are based on cross-sectional data of the adult population living in Germany (N = 2413). SSS was assessed with the Somatic Symptom Scale-8. A multiple linear regression model with three-way interaction of gender, income and history of migration and post-hoc pairwise comparison of estimated marginal means was conducted. Analyses revealed intersectional inequalities in SSS along the axis of gender, income, and history of migration. Highest SSS was found in males with low income whose parent(s) immigrated, females with low income who immigrated themselves, and females with low income and no history of migration. Intersectional approaches contribute to a more comprehensive understanding of health disparities. To reduce disparities in SSS, proportionate universal interventions combining universal screening and targeted treatment seem promising.

Functional Somatic Disorders, Their Subtypes, and Their Association With Self-Rated Health in the German General Population

OBJECTIVE

The heterogeneous conceptualizations and classifications of persistent and troublesome physical symptoms impede their adequate clinical management. Functional somatic disorder (FSD) is a recently suggested interface concept that is etiologically neutral and allows for dysfunctional psychobehavioral characteristics as well as somatic comorbidity. However, its prevalence and impact are not yet known.

METHODS

We analyzed 2379 participants (mean age = 48.3 years, 52.5% female) from a representative German community survey using operationalized FSD criteria. These criteria defined FSD types based on somatic symptom count, type, and severity assessed by the Bodily Distress Syndrome Checklist. In addition, the associations of those types with health concerns, comorbidity, psychological distress, and self-rated health were determined.

RESULTS

There were four clearly demarcated groups with no relevant bothering symptoms, with one or with few bothering symptoms from one organ system, and with multiple bothering symptoms from at least two organ systems. Psychological distress, health concerns, and comorbidity steadily increased, and self-rated health decreased according to the number and severity of symptoms. Somatic symptom burden, health concerns, and comorbidity independently predicted self-rated health, with no interaction effect between the latter two.

CONCLUSIONS

Our data support an FSD concept with two severity grades according to persistent and troublesome symptoms in one versus more organ systems. The delimitation of subtypes with psychobehavioral characteristics and/or with somatic comorbidity seems useful, while still allowing the demarcation of a group of participants with high symptom burden but without those additional characteristics.

Comparing the occurrence of chronic physical disorders in self-employed individuals with that of employees: A systematic review

BACKGROUND

A stringent systematic review of population-based observational studies focusing on the physical health of self-employed individuals as a basis for the development of targeted prevention strategies is lacking.

OBJECTIVE

We aimed to systematically evaluate all the studies of good quality that compared the occurrence of chronic physical disorders in self-employed individuals with that of employees.

METHODS

We searched three major medical databases (MEDLINE, Web of Science, Embase) following the Cochrane guidelines. The quality of the studies was rated based on the slightly modified validated assessment tool that was developed by Hoy et al.RESULTS:We included 16 population-based studies of good quality, with data from 15,369,964 participants in total. The two longitudinal evaluations of Swedish national registers with the longest follow-up periods showed increased cardiovascular mortality and incidence estimates of cardiovascular disease in self-employed individuals compared with those of white-collar (i.e., nonmanual) employees but decreased risk estimates compared with those of blue-collar (i.e., manual) workers. The results of the shorter cohort studies were heterogeneous. In cross-sectional studies, prevalence estimates for musculoskeletal, respiratory and malignant diseases were higher among self-employed individuals than among employees.

CONCLUSION

The long-term cardiovascular disease risk and mortality of self-employed individuals seemed to be higher than those of white-collar employees but lower than those of blue-collar employees. As a basis for targeted prevention strategies, further longitudinal studies in different settings are required to better understand the development of physical health disorders for specific self-employment categories such as sole proprietors, small entrepreneurs, family businesses and others.

Efficacy of Heart Rate Variability Biofeedback for Somatic Symptom Disorder: A Pilot Randomized Controlled Trial

OBJECTIVE

Patients with somatic symptom disorder (SSD) often receive targeted intervention only after a long duration of illness. Moreover, the reported effect sizes of interventions for SSD are small. Therefore, improvement and evaluation of interventions are needed. Preliminary evidence suggests autonomic imbalance, for example, lower heart rate variability (HRV) in SSD. HRV biofeedback (HRV-BF) as a method for self-regulation shows initial positive effects in chronic pain and functional syndromes. The aim of this study was to evaluate the efficacy of a brief HRV-BF intervention for SSD.

METHODS

Of a total of 50 participants with SSD ( Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ) who were recruited and randomly assigned to four sessions of HRV-BF ( n = 25) or autogenic training (AT; n = 25), 49 participants were analyzed (female, 77.6%; mean [standard deviation] age = 45.3 [14.4] years). The primary outcomes were somatic symptom severity (Screening for Somatoform Disorders, numeric rating scale) and HRV. Secondary outcomes were psychological characteristics of SSD (e.g., the Somatic Symptom Disorder 12 scale, health concerns, emotion regulation). The data were collected before and after intervention and were analyzed with repeated-measures analyses of variance and post hoc t tests.

RESULTS

Symptom severity improved after both, HRV-BF and AT. Standard Deviation of the NN Interval and psychological symptoms improved significantly more strongly in the HRV-BF than in the AT group (e.g., Standard Deviation of the NN Interval: ηp2 interaction = 0.10, p = .047).

CONCLUSIONS

The improvements in somatic symptoms, but specifically in cognitive-affective symptoms and autonomic regulation, suggest that HRV-BF with only four sessions is a potentially useful intervention option for SSD. Thus, adding this short HRV-BF intervention to existing psychological treatments for SSD may be promising.Trial Registration : German Clinical Trial Register identifier DRKS00017099 ( https://www.drks.de ).

Stability and predictors of somatic symptoms in men and women over 10 years: A real-world perspective from the prospective MONICA/KORA study

OBJECTIVE

To assess the stability of somatic symptoms in community-dwelling participants.

METHODS

The study included 2472 participants (1190 men, 1282 women; mean age 44.3 ± 10.9) from the prospective population-based MONICA-S3 cohort (1994/95) and the 10-year follow-up KORA-F3 cohort. Somatic symptoms were assessed by an adapted version of the Somatic Symptom Scale-8 (SSS-8a) with scores ranging from 0 to 24. Somatic symptom stability was assessed by weighted kappa values (κ). Generalized Estimating Equation models assessing symptom stability were adjusted for sociodemographic, lifestyle, clinical and psychosocial risk factors, as well as pre-existing medical conditions.

RESULTS

The mean (±SD) SSS-8a was lower in men (S3: 6.88 ± 3.87, F3: 6.60 ± 3.86) than women (S3: 8.43 ± 4.0, F3: 8.31 ± 4.2) at both time points. However, somatic symptoms remained moderately stable in both genders over 10 years (κ =0.42 in men and κ = 0.48 in women), with the largest stability observed in trouble sleeping for men (κ =0.41) and pain in the joints for women (κ =0.41). Pre-existing somatic symptoms were significantly associated with increasing symptoms at follow-up [men: β = 0.82 (SE 0.12), women: β = 0.85 (SE 0.12)], followed by age and psychosocial factors, whereas higher education and recent health care utilization were inversely associated with increasing symptoms. Although hypertension and obesity were associated with increasing somatic symptoms in men, pre-existing medical conditions were not associated with increasing somatic symptoms in men nor women.

CONCLUSIONS

The current findings indicate that somatic symptoms remain moderately stable in the general population during 10 years of follow-up, mainly driven by sociodemographic and psychosocial factors.

Gender specific somatic symptom burden and mortality risk in the general population

Gender specific all-cause mortality risk associated with a high somatic symptom burden (SSB) in a population-based cohort was investigated. The study population included 5679 women and 5861 men aged 25-74 years from the population-based MONICA/KORA Cohort. SSB was assessed following the Somatic Symptom Scale-8 and categorized as very high (≥ 95th percentile), high (60-95th percentile), moderate (30-60th percentile), and low (≤ 30th percentile). The impact of SSB on all-cause mortality risk within a mean follow-up period of 22.6 years (SD 7.1; 267,278 person years) was estimated by gender-specific Cox regression models adjusted for sociodemographic, lifestyle, somatic and psychosocial risk factors, as well as pre-existing medical conditions. Approximately 5.7% of men and 7.3% of women had very high SSB. During follow-up, 3638 (30.6%) mortality cases were observed. Men with a very-high SSB had 48% increased relative risk of mortality in comparison to men with a low SSB after adjustment for concurrent risk factors (1.48, 95% CI 1.20-1.81, p < .0001), corresponding to 2% increased risk of mortality for each 1-point increment in SSB (1.02; 95% CI 1.01-1.03; p = 0.03). In contrast, women with a very high SSB had a 22% lower risk of mortality (0.78, 95% CI 0.61-1.00, p = 0.05) and women with high SSB had an 18% lower risk of mortality (0.82; 95% CI 0.68-0.98, p = 0.03) following adjustment for concurrent risk factors. The current findings indicate that an increasing SSB is an independent risk factor for mortality in men but not in women, pointing in the direction of critical gender differences in the management of SSB, including women's earlier health care utilization than men.

[Functional somatic symptoms: Clinical varieties, diagnostic challenges, therapeutic principles]

Functional somatic symptoms are common and multiform. They occur in all genders and age groups, with and without somatic or mental comorbidity. Dysfunctional illness behaviour on the patients' (e. g., excessive attention or anxiety) and also on the caregivers' side (e. g., nocebo messages, redundant investigations or risky treatments) can promote chronification. Empathy, well balanced diagnostics, comprehensible information within individual multifactorial explanatory models, refocussing, activation, and - in more severe forms - additional measures such as psychotherapy are recommended.

Spontaneously reported persistent symptoms related to coronavirus disease 2019 one year after hospital discharge : A retrospective cohort single-center study

Background

There are no outcome studies for coronavirus disease 2019 (COVID-19) survivors one year after hospital discharge in Germany.

Methods

This retrospective cohort study included all patients with polymerase chain reaction (PCR)-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hospitalized in the departments of internal medicine of the Klinikum Saarbrücken, a tertiary care hospital, between March 15 and December 31, 2020. A telephone interview with survivors was conducted at least 12 months after discharge. The interview was initiated with an open-ended question whether the patient had fully recovered from the disease. In the event of a subjective incomplete recovery, the patient was prompted to report any continuous or frequent symptoms that had not occurred prior to COVID-19. Finally, independent of the open-ended question response, all patients were asked closed questions which addressed new symptom onset of persistent fatigue, cognitive dysfunction, headache, muscle and joint pain following COVID-19.

Results

In all, 235 survivors were contacted and 162 could be included in the analysis. In 55 of 162 interviews (34.0%) at least one persistent COVID-19 symptom (PCS) was spontaneously reported. Four of 55 survivors with PCS reported five additional symptoms on the closed questions. One survivor, who responded positively to the open-ended question, reported new onset PCS in response to the closed questions. Physical fatigue (24.7%), cognitive dysfunction (14.8%), shortness of breath (8.6%), muscle and joint pain (6.8%) and headache (6.2%) were the most frequently reported PCS.

Conclusions

Despite an interview technique aimed to reduce attribution bias by patients, one third of COVID-19 inpatient survivors report PCS one year after hospitalization.

The complete article is written in English.

[Psychological Distress in Former Eastern and Western States 30 Years After the Reunification]

OBJECTIVE

Investigating the effects of internal migration on somatoform complaints (GBB-8) as well as psychological distress (PHQ-4; captures symptoms of anxiety and depression).

METHODS

A representative sample from 2019 is used and divided into four groups (West, East, East-West, West-East). A variance analysis was conducted.

RESULTS

The West group reports significantly more distress and somatoform symptoms than the East group. The group East-West report significantly more distress and somatoform complaints.

CONCLUSION

The influence of internal migration, especially from East to West Germany, should be considered in future studies.

Somatic symptoms in the Eastern and Western states of Germany 30 years after unification: Population-based survey analyses

Background Following German reunification, physical health indicators in the formerly separated states (German Democratic Republic- East/ Federal Republic of Germany-West) have converged. However, it remains unclear how these societal changes have impacted somatic complaints, a major indicator of physical and mental health. Therefore, we investigated how somatic symptom reporting in men and women evolved regarding residency. Methods We administered cross-sectional surveys representative of the German population with comparable sample size in 1994 (N = 3047), 2001 (N = 2050), 2013 (N = 2508) and 2019 (N = 2531) following random route procedure. Men and women aged 14-99 reported demographics and filled the Gießen Complaint List, a standardized questionnaire, to assess major physical symptoms. Results Residency in the Eastern states was a determinant of higher symptom load in 2001 (β = 0.11, SE = 0.02, [95% CI = 0.07 to 0.15], p < .001) where symptom reporting has been consistently higher compared to the West from 1994 through 2013. However, in 2019, the pattern reversed and residency in the East was associated with lower symptom load (β = -0.15, SE =0.02, [95% CI = -0.19 to -0.11], p < .001). Predictors of high symptom load among all surveys were higher age, female sex, and low household income. Conclusions Symptom reporting did not converge, but reversed in 2019, with a higher symptom load in the Western states. This finding is particularly intriguing since other determinants, e.g., socioeconomic factors have converged, but have remained unfavorable in the East.

Fatigue as the Chief Complaint – Epidemiology, Causes, Diagnosis, and Treatment

BACKGROUND

Fatigue is a main or secondary reason for 10-20% of all consultations with a primary care physician.

METHODS

This review is based on pertinent publications retrieved by a comprehensive, selective literature search on the epidemiology, etiology, and diagnostic evaluation of fatigue as a leading symptom of disease, as well as on the treatment of its common causes. Information was also included from the literature search we conducted for the German clinical practice guideline on fatigue that was issued by the German College of General Practitioners and Family Physicians (Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin, DEGAM).

RESULTS

Fatigue can be due to any of a broad spectrum of diseases, including decompensation of already known conditions. Sleep disorders and sleep-related disorders of breathing, depression (18.5%), and excessive psychosocial stress are the most common causes of persistent fatigue. Previously undiagnosed cancer is a rare cause, accounting for only 0.6% of cases (95% confidence interval [0.3; 1.3]). Anemia and other organic causes are rare as well (4.3% [2.7; 6.7]). Investigations beyond the history, physical examination, and simple laboratory tests are needed only in the presence of additional symptoms or findings. If the diagnosis remains unclear, watchful waiting and regularly scheduled follow-up help prevent an excessive focus on somatic causes, leading to overdiagnosis. Irrespective of specific causes, psychoeducative and psychotherapeutic approaches should be discussed with the patient, as well as an individually adapted exercise program.

CONCLUSION

The work-up of fatigue as a chief complaint should be guided by investigating common and/or potentially dangerous disorders. Since the latter are rare, an exclusively somatic focus should be avoided in order to prevent overdiagnosis.

Assessment of functional somatic disorders in epidemiological research: Self-report questionnaires versus diagnostic interviews

OBJECTIVE

Self-reported symptom questionnaires are often used for identifying individuals with functional somatic disorders (FSD) in epidemiological research. Studies on their validity in establishing clinically valid cases are, however, lacking. We aimed to compare and dissect the processes of identifying participants with FSD with symptom questionnaires and FSD diagnoses established by diagnostic interviews.

METHODS

Individuals from the adult Danish population (n = 1590) filled in symptom questionnaires and participated in a diagnostic research interview, performed over telephone by trained family physicians. The two methods were described and compared in different steps: 1) Agreement on presence of symptoms, 2) agreement after FSD symptom pattern criteria had been applied, and 3) agreement on final FSD diagnoses.

RESULTS

Agreement on symptom presence was high (>82%). Using FSD symptom pattern criteria, the two methods agreed in 30-62% of cases within each category. Discrepancies were mainly due to participants fulfilling symptom patterns in the interview but not in the questionnaires. Agreement between final FSD questionnaire cases and final FSD interview diagnoses was moderate (>68%) with lower FSD prevalence in the interview (26.2% vs 44.5%). Discrepancies were largely explained by the interviewers assessing the symptom patterns to be caused by an alternative physical or mental condition.

CONCLUSION

Prevalence of final FSD diagnoses were markedly lower in the diagnostic interview compared to self-reported questionnaires cases; mainly because of the clinical evaluation of symptom attribution and impairment. Symptom questionnaires may be valuable as screening tools and as trans-diagnostic comparison while diagnostic interviews are necessary in establishing clinically significant FSD diagnoses.

Association of Psychometric Indices and Normal Electrodiagnostic Studies in Referral for Suspected Carpal Tunnel Syndrome

BACKGROUND/AIM

The aim of this study was to investigate psychometric indices and their association with electrodiagnostic studies (EDX).

PATIENTS AND METHODS

A total of 100 patients referred for EDX testing of the upper limbs were prospectively enrolled. Demographic data, laboratory test results, referral physician specialty, main symptom, WHODAS 2.0-12 item version, Hospital Anxiety and Depression Scale (HADS), Boston Carpal Tunnel Questionnaire (BCTQ) and a Numeric Rating Scale (NRS) indicating the extent of their discomfort were collected.

RESULTS

Normal EDX results were elicited from 56% of patients. Only the presence of numbness in the right hand, pain in the left hand and older age were significantly associated with an abnormal EDX result. The more depressed and anxious the patients were, the more they scored on psychometric scales.

CONCLUSION

The large prevalence of normal EDX studies raises the issue of unnecessary referrals. A proportion of patients are referred only according to their reported symptoms. Psychological factors affect the way a person expresses physical discomfort, leading to unnecessary EDX referrals and inevitably with normal results.

A Conditional Process Model to Explain Somatization During Coronavirus Disease 2019 Epidemic: The Interaction Among Resilience, Perceived Stress, and Sex

Background

More than 15% of Chinese respondents reported somatic symptoms in the last week of January 2020. Promoting resilience is a possible target in crisis intervention that can alleviate somatization.

Objectives

This study aims to investigate the relationship between resilience and somatization, as well as the underlying possible mediating and moderating mechanism, in a large sample of Chinese participants receiving a crisis intervention during the coronavirus disease 2019 epidemic.

Methods

Participants were invited online to complete demographic information and questionnaires. The Symptom Checklist-90 somatization subscale, 10-item Connor–Davidson resilience scale, and 10-item Perceived Stress Scale were measured.

Results

A total of 2,557 participants were included. Spearman correlation analysis revealed that lower resilience was associated with more somatic symptoms (p < 0.001). The conditional process model was proved (indirect effect = −0.01, 95% confidence interval = [−0.015, −0.002]). The interaction effects between perceived stress and sex predicted somatization (b = 0.05, p = 0.006).

Conclusion

Resilience is a key predictor of somatization. The mediating effects of perceived stress between resilience and somatization work in the context of sex difference. Sex-specific intervention by enhancing resilience is of implication for alleviating somatization during the coronavirus disease 2019 epidemic.

Functional pain disorders - more than nociplastic pain

BACKGROUND

Nociplastic pain has been recently introduced as a third mechanistic descriptor of pain arising primarily from alterations of neural processing, in contrast to pain due to tissue damage leading to nociceptor activation (nociceptive) or due to lesion or disease of the somatosensory nervous system (neuropathic). It is characterized by hyperalgesia and allodynia, inconsistency and reversibility, as well as dynamic cross-system interactions with biological and psychobehavioral factors. Along with this renewed understanding, functional pain disorders, also classified as chronic primary pain, are being reframed as biopsychosocial conditions that benefit from multimodal treatment.

OBJECTIVE

To summarize the current understanding of nociplastic pain and functional pain disorders, with a focus on conditions that are common in neurology practice.

METHODS

This was a narrative literature review.

RESULTS

Chronic back pain, fibromyalgia syndrome and complex regional pain syndrome are best understood within a biopsychosocial framework of pain perception that considers structural factors (predispositions and sequelae) and psychobehavioral mechanisms. Although pain is often the primary complaint, it should not be the only focus of treatment, as accompanying symptoms such as sleep or mood problems can significantly impact quality of life and offer useful leverage points for multimodal treatment. Analgesic pharmacotherapy is rarely helpful on its own, and should always be imbedded in a multidisciplinary setting.

The BDS checklist as measure of illness severity: a cross-sectional cohort study in the Danish general population, primary care and specialised setting

OBJECTIVE

The bodily distress syndrome (BDS) checklist has proven to be useful in the diagnostic categorisation and as screening tool for functional somatic disorders (FSD). This study aims to investigate whether the BDS checklist total sum score (0-100) can be used as a measure of physical symptom burden and FSD illness severity.

DESIGN

Cross-sectional.

SETTING

Danish general population, primary care and specialised clinical setting.

PARTICIPANTS

A general population cohort (n=9656), a primary care cohort (n=2480) and a cohort of patients with multiorgan BDS from specialised clinical setting (n=492).

OUTCOME MEASURES

All data were self-reported. Physical symptoms were measured with the 25-item BDS checklist. Overall self-perceived health was measured with one item from the 36-item Short-Form Health Survey (SF-36). Physical functioning was measured with an aggregate score of four items from the SF-36/SF-12 scales 'physical functioning', 'bodily pain' and 'vitality'. Emotional distress was measured with the mental distress subscale (SCL-8) from the Danish version of the Hopkins Symptom Checklist-90. Illness worry was measured with the six-item Whiteley Index.

RESULTS

For all cohorts, bifactor models established that despite some multidimensionality the total sum score of the BDS checklist adequately reflected physical symptom burden and illness severity. The BDS checklist had acceptable convergent validity with measures of overall health (r=0.25-0.58), physical functioning (r=0.22-0.58), emotional distress (r=0.47-0.62) and illness worry (r=0.36-0.55). Acceptability was good with a low number of missing responses to items (<3%). Internal consistency was high (α ≥0.879). BDS score means varied and reflected symptom burden across cohorts (13.03-46.15). We provide normative data for the Danish general population.

CONCLUSIONS

The BDS checklist total sum score can be used as a measure of symptom burden and FSD illness severity across settings. These findings establish the usefulness of the BDS checklist in clinics and in research, both as a diagnostic screening tool and as an instrument to assess illness severity.