Examine the public health impacts of functional somatic disorders using the DanFunD study.

Background: Persistent physical symptoms (e.g. pain, fatigue) are prevalent in the population and some persons may develop a functional somatic disorder (FSD). We still need to explore the limits between general bodily sensations and FSD, and great controversies exist as regard delimitation, occurrence, risk factors, prognosis, and costs of FSD in the general population. This is mainly due to the lack of focused, sufficient powered, population-based epidemiological studies. Material and Methods: The DanFunD study is the largest focused population-based study on FSD and has the potential to answer these crucial questions regarding the FSD disorders. DanFunD has its origin in the Copenhagen area of Denmark and was initiated in 2009 by an interdisciplinary team of researchers including basic scientists, clinical researchers, epidemiologists, and public health researchers. A population-based cohort of nearly 10,000 people have filled in detailed questionnaires, gone through a thorough health examination, and a biobank is established. The cohort was re-examined after five years. Results:The prevalence of FSD in the Danish population is about 10-15% and is twice as common in women as in men. Persons with FSD report impaired daily activities and low self-perceived health, which qualifies FSD as a major public health problem. The research plan to unravel the risk factors for FSD employs a bio-psycho-social approach according to a detailed plan. Preliminary results are presented, and work is in progress. Likewise, plans for assessing prognosis and health care costs are provided. Conclusion: We invite researchers in the field to collaborate on this unique data material.

The impact of the Covid-19 pandemic on mental and physical health in Denmark - a longitudinal population-based study before and during the first wave.

BACKGROUND: In the continuation of the first wave of the Covid-19 outbreak in Denmark, unprecedented restrictions with great impact on the citizen's everyday life were implemented. The objectives of this study were to investigate the influence of the Covid-19 pandemic on mental and physical health in the Danish population during the spring 2020 first wave outbreak and lockdown. METHODS: A sample from the adult Danish population (n = 2190) were included. Self-reported measures of illness worry (Whiteley-6-R), emotional distress (SCL-90), and physical symptom load (SLC-90) were obtained before and during the first wave of the pandemic and compared with Wilcoxon signed-rank tests. Impact of covariates on physical and mental health was evaluated with ordinal regression analyses. Results from a tailored questionnaire regarding the Covid-19 pandemic were presented to explore the direct impact of the pandemic. RESULTS: We only found minor increases in illness worry, emotional distress and physical symptom load (0-1 points difference, p ≤ 0.007) during the Covid-19 pandemic compared to before the pandemic. Sex, age, education, and physical disease were not associated with illness worry, emotional distress, or physical symptom load. Overall, the participants were trustful in the authorities' recommendations and felt that they managed the pandemic and the restrictions to a great extent despite that some expected great/major future consequences of the pandemic. CONCLUSIONS: This study suggested that the first wave of the Covid-19 pandemic only had minor impact on mental and physical health in the Danish general population. Future studies should address the impact of the second wave of the pandemic and the renewed implementation of the concomitant restrictions.

Neuroticism, perceived stress, adverse life events and self-efficacy as predictors of the development of functional somatic disorders: longitudinal population-based study (DanFunD).

BACKGROUND: Functional somatic disorder (FSD) is a unifying diagnosis that includes functional somatic syndromes such as irritable bowel, chronic widespread pain (CWP) and chronic fatigue. Several psychological factors are associated with FSD. However, longitudinal population-based studies elucidating the causal relationship are scarce. AIMS: To explore if neuroticism, perceived stress, adverse life events (ALEs) and self-efficacy can predict the development of FSD over a 5-year period. METHOD: A total of 4288 individuals who participated in the DanFunD baseline and 5-year follow-up investigations were included. FSD was established at both baseline and follow-up, with symptom questionnaires and diagnostic interviews. Neuroticism was measured with the short-form NEO Personality Inventory, perceived stress with the Cohen's Perceived Stress Scale, ALEs with the Danish version of the Cumulative Lifetime Adversity Measure and self-efficacy with the General Self-Efficacy Scale. Associations were investigated with multiple logistic regression models. RESULTS: Perceived stress predicted incident FSD, irritable bowel, CWP and chronic fatigue (odds ratios: 1.04-1.17). Neuroticism predicted incident FSD and chronic fatigue (odds ratios: 1.03-1.16). ALEs predicted incident FSD, CWP and chronic fatigue (odds ratios: 1.06-1.18). An increase in perceived stress from baseline to follow-up was associated with incident FSD, irritable bowel, CWP and chronic fatigue (odds ratios: 1.05-1.22). Contrary, an increase in self-efficacy seemed to be a protective factor (odds ratios: 0.89-0.99). CONCLUSIONS: High neuroticism, high perceived stress and a high number of ALEs are risk factors for the development of FSD. Particularly perceived stress seems to be an important contributor to the onset of FSD.

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.

Coping strategies among individuals with multiple physical symptoms: A general population-based cross-sectional study.

OBJECTIVE: Coping has been suggested as a perpetuating factor for physical symptoms. The aim of this study was to examine the use of the coping strategies approach, resignation, and diversion in individuals with multiple physical symptoms according to the construct of Bodily Distress Syndrome (BDS). METHODS: This cross-sectional study was part of the nationwide web-based survey Danish Symptom Cohort (DaSC). In total, 100,000 individuals were invited to participate, and individuals eligible for the present study were respondents aged 20-64 years without a current or recent pregnancy. Multiple physical symptoms were identified using the BDS checklist, and coping was assessed by the Brief Approach/Avoidance Coping Questionnaire. Statistical analyses included descriptive statistics and multinomial and logistic regression. RESULTS: A total of 35,810 respondents were included in the study, of which 8512 (23.8%) fulfilled the criteria for having multiple physical symptoms. This group of respondents had lower coping scores on approach and higher coping scores on resignation and diversion compared with the non-BDS group. The regression analyses showed that high scores on approach were associated with a lower probability of having multiple symptoms (adjusted OR 0.92, 95% CI: 0.91-0.92), whereas high scores on diversion and resignation were associated with a higher probability of having multiple symptoms (adjusted OR 1.10; 95% CI: 1.09-1.11 and adjusted OR 1.19; 95% CI: 1.18-1.20, respectively). CONCLUSION: The study supports the hypothesis that experiencing multiple physical symptoms is associated with certain coping strategies. This is relevant knowledge for health care professionals who will be treating this patient group.

Examining associations between early adverse life events and health anxiety using the DanFund study.

Childhood adverse life events, in particular illness-related events, have been proposed as a risk factor for development of health anxiety. OBJECTIVE: To examine: 1) The association between accumulated early adverse life events and health anxiety in adulthood and 2) The influence of specific types of life events, i.e., illness, injury, loss, and the impact of their exposure time on health anxiety in adulthood. METHOD: A population-based, cross-sectional study including 7454 participants from the Danish study of Functional Disorders (DanFunD). Health anxiety was assessed with Whiteley-6-R and early adverse life events with the Cumulative Lifetime Adversity Measure. Caseness was defined as a Whiteley-6-R score ≥ 90%ile. Generalised linear models were used to estimate the association with relative risk (RRa, adjusted for sociodemographics). RESULTS: A cumulative effect was found for each additional adverse life event with 8.03% increased risk of health anxiety. Two categories were associated with a higher risk: violence (RRa = 1.65, 95% CI: 1.37-1.99, P < 0.001) and relationship stress (RRa = 1.34; 95% CI: 1.15-1.57, P < 0.001). Respondents with self-reported childhood illness were also more likely to report health anxiety (RRa = 1.52, 95% CI 1.11-2.09, P = 0.009). Timewise, health anxiety seemed associated with illness during school age and injury during adolescence. CONCLUSIONS: Accumulated adverse life events, early exposure to specific categories and specific health-related life events were associated with self-reported health anxiety in adulthood. Our findings provide new knowledge on the potential role of early life events in health anxiety which could inform early intervention.

High Perceived Stress and Low Self-Efficacy are Associated with Functional Somatic Disorders: The DanFunD Study.

Objective: Several psychological factors have been proposed to be associated with functional somatic disorders (FSD) including functional somatic syndromes, such as irritable bowel, chronic widespread pain, and chronic fatigue. However, large randomly selected population-based studies of this association are sparse. This study aimed to investigate the association between FSD and perceived stress and self-efficacy, respectively, and to investigate if FSD differed from severe physical diseases on these aspects. Methods: This cross-sectional study included a random sample of the adult Danish population (n = 9656). FSD were established using self-reported questionnaires and diagnostic interviews. Perceived stress was measured with Cohen's Perceived Stress Scale and self-efficacy with the General Self-Efficacy Scale. Data were analysed with generalized linear models and linear regression models. Results: FSD were associated with higher perceived stress and lower self-efficacy, especially for the multi-organ and the general symptoms/fatigue FSD types and for chronic fatigue. However, controlling for the personality trait neuroticism altered the associations with self-efficacy so it became insignificant. The analysis did not support an important interaction between perceived stress and self-efficacy on the likelihood of having FSD. Individuals with FSD presented levels of perceived stress that were not equal, ie higher, to those in individuals with severe physical diseases. Conclusion: FSD were positively associated with perceived stress and negatively associated with self-efficacy. Our study may point to stress being part of the symptomatology of FSD. This underlines the severity of having FSD and stresses the relevance of the resilience theory in the understanding of the condition.

Are Sexual Assaults Related to Functional Somatic Disorders? A Cross-Sectional Study.

An increasing number of sexual assaults (SAs) are being reported. This study investigated associations between SA and FSD, conceptualized as bodily distress syndrome (BDS), and five functional somatic syndromes (FSSs): chronic widespread pain (CWP), irritable bowel (IB), chronic fatigue (CF), multiple chemical sensitivity (MCS), and whiplash-associated disorder (WAD). Participants (n = 7493) from the population-based cohort Danish Study of Functional Disorders (DanFunD) completed questionnaires on FSD, emotional distress, SA, and sociodemographics. Risk ratios (RRs) for each FSD and emotional distress were calculated in nine models with SA as the primary exposure using generalized linear models with binomial family and log link and were adjusted for other potential risk factors. The results showed that SA was associated with single-organ FSD (RR = 1.51; 95% CI = 1.22-1.87), multi-organ FSD (RR = 3.51; 95% CI = 1.89-6.49), CWP (RR = 1.28; 95% CI = 0.83-1.98), IB (RR = 2.00; 95% CI = 1.30-3.07), CF (RR = 1.81; 95% CI = 1.42-2.32), WAD (RR = 2.62; 95% CI = 1.37-5.03), MCS (RR = 3.04; 95% CI = 1.79-5.17), emotional distress (RR = 1.75; 95% CI = 1.21-2.54), and health anxiety (RR = 1.65; 95% CI = 1.10-2.46). Overall, SA victims experienced significantly more somatic symptoms than individuals not exposed to SA. Adjusting for physical and emotional abuse did not change the observed associations. Our results suggest a large impact of SA on the overall somatic and mental health of SA victims. Due to the cross-sectional study design, further studies are required.

Detection of illness worry in the general population: A specific item on illness rumination improves the Whiteley Index.

OBJECTIVE: The Whiteley Index (WI) is the most widely used screening tool for health anxiety/illness worry. Diverse versions (different number of items and factors) have been used. We aimed to examine psychometric properties of 7 items of the WI besides adding a new item on obsessive illness rumination for better future detection of health anxiety. METHODS: Data from a large population-based study in Denmark (N = 9656). Construct validity was examined by exploratory (EFA) and confirmatory factor analysis (CFA) plus hypothesis testing. Criterion validity was evaluated via Receiver Operating Characteristic curves and area under the curve (AUC) using a diagnostic criterion as gold standard. RESULTS: Factor loadings of EFA revealed viable one-factor models (6, 7, or 8 items) and two-factor models (7 or 8 items). Factor one indicated a dimension of illness worry. Factor two indicated a somatic symptoms dimension. The new item on obsessive illness rumination merged well with the existing items. EFA of two-factor models and one-factor 6-item model showed good fit. CFA resembles these findings. A one-factor 6-item model (including the item on obsessive illness rumination and excluding two items concerning somatic symptoms) was chosen as the optimal model and presented good criterion validity: AUC 0.88 (95%CI(0.84;0.92)). Main hypotheses concerning associations with somatic symptoms, anxiety, and depression were met. CONCLUSIONS: We found good psychometric properties for a new one-factor 6-item version of the WI. Through elimination of items concerning somatic symptoms and inclusion of obsessive illness rumination, we propose a clear, unidimensional and improved measure of illness worry: Whiteley-6-R.

Adverse life events in the general population - a validation of the cumulative lifetime adversity measure.

Background: Negative life events are a predictor for mental illness. However, most research has focused on selected domains, e.g. childhood or recent adversity. The Cumulative Lifetime Adversity Measure (CLAM), a newly introduced questionnaire not yet validated, examines cumulative effect of a range of events including number of exposure to the same event. This measure gives opportunity to collect detailed data on lifetime adversity in large cohort studies. Objective: The aim of this study was translation of the CLAM into Danish and validation of the CLAM in a large general population cohort. Secondly, we aimed to describe the occurrence of adverse life events in a large representative sample of the general population in Denmark. Methods: Translation and validation followed the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) for formative models. Content and construct validity were evaluated including hypothesis testing of accumulated lifetime adversity having a U-shaped pattern with low levels of cumulated lifetime adversity as opposed to no or high levels being associated with lower emotional distress, functional impairment, and pain impairment. The field testing sample was the DanFunD cohort (n = 7493) randomly drawn in a Danish population and examined between 2012 and 2015. Results: Pilot interviews showed that the questions were confronting but not offensive, straight forward, and easy to answer. Acceptability was good. U-shaped patterns between accumulated lifetime adversity and the outcome measures were found. Quadratic term: Emotional distress (ß(95%CI) 0.007(0.002;0.012), p < 0.007), functional impairment (ß(95%CI) -0.002(-0.003;-0.001), p < 0.001), and pain impairment (ß(95%CI) 0.004(0.002;0.006), p = 0.001). Field testing provided basic numbers for adverse life events for the Danish general population, with a cumulated lifetime adversity mean (SD), 5.9 (3.7). Compared to the US there were lower rates of violence, social/environmental stress, and disaster. Conclusions: The results from the original version were replicated, indicating high construct validity. Furthermore, content validity was good.

Antecedentes: Los eventos vitales negativos son un predictor de trastorno mental. Sin embargo, la mayoría de las investigaciones se han centrado en dominios seleccionados, por ej. infancia o adversidad reciente. La Medida de Adversidad Acumulada a lo Largo de la Vida (CLAM en su sigla en inglés), un cuestionario recientemente introducido que no ha sido validado todavía, examina el efecto acumulado de un rango de eventos, incluyendo el número de exposiciones al mismo evento. Esta medida permite recolectar información detallada sobre la adversidad a lo largo de la vida en estudios de cohorte grandes.Objetivo: El objetivo de este estudio fue la traducción de la CLAM al idioma danés y la validación de la CLAM en una cohorte grande de población general. En segundo lugar, buscamos describir la ocurrencia de los eventos vitales adversos en una muestra representativa grande de la población general en Dinamarca.Métodos: La traducción y la validación siguió los Estándares basados en Consensos para la selección de los Instrumentos de Medición en Salud (COSMIN en su sigla en inglés) para modelos formativos. La validez de contenido y constructo fueron evaluadas incluyendo la puesta a prueba de la hipótesis de que la adversidad acumulada a lo largo de la vida tiene un patrón de forma en U con bajos niveles de adversidad acumulada a lo largo de la vida, en lugar de niveles nulos o altos, está asociado con más baja angustia emocional, discapacidad funcional, y deterioro del dolour. La muestra de prueba de campo fue una cohorte de DanFunD (n=7493) obtenida aleatoriamente de una población danesa y examinada entre el 2012-2015.Resultados: Las entrevistas piloto mostraron que las preguntas fueron confrontativas pero no ofensivas, directas, y fáciles de contestar. La aceptabilidad fue buena. Se encontraron patrones en forma de U entre la adversidad acumulada a lo largo de la vida y las medidas de los resultados. En términos cuadráticos: Angustia emocional (ß(IC 95%) 0,007(0,002;0,012), p<0.007), discapacidad funcional (ß(IC 95%) −0,002(−0,003;-0,001), p<0.001), y deterioro del dolour (ß(IC 95%) 0,004(0,002;0,006), p=0.001). La prueba de campo proporcionó los números básicos para los eventos vitales adversos para la población general danesa, con una adversidad acumulada a lo largo de la vida promedio (DE), 5.9 (3.7). En comparación con los Estados Unidos, se reportan tasas más bajas de violencia, estrés social/ambiental, y desastre.Conclusiones: Los resultados de la versión original fueron replicados, indicando una validez de constructo alta. Además, la validez de contenido fue buena.

Sick Leave within 5 Years of Whiplash Trauma Predicts Recovery: A Prospective Cohort and Register-Based Study.

BACKGROUND: 10-22% of individuals sustaining whiplash trauma develop persistent symptoms resulting in reduced working ability and decreased quality of life, but it is poorly understood why some people do not recover. Various collision and post-collision risk factors have been studied, but little is known about pre-collision risk factors. In particular, the impact of sickness and socioeconomic factors before the collision on recovery is sparsely explored. The aim of this study was to examine if welfare payments received within five years pre-collision predict neck pain and negative change in provisional situation one year post-collision. METHODS AND FINDINGS: 719 individuals with acute whiplash trauma consecutively recruited from emergency departments or primary care after car accidents in Denmark completed questionnaires on socio-demographic and health factors immediately after the collision. After 12 months, a visual analogue scale on neck pain intensity was completed. 3595 matched controls in the general population were sampled, and national public register data on social benefits and any other welfare payments were obtained for participants with acute whiplash trauma and controls from five years pre-collision to 15 months after. Participants with acute whiplash trauma who had received sickness benefit for more than 12 weeks pre-collision had increased odds for negative change in future provisional situation (Odds Ratio (OR) (95% Confidence Interval (CI) = 3.8 (2.1;7.1)) and future neck pain (OR (95%CI) = 3.3 (1.8;6.3)), controlling for other known risk factors. Participants with acute whiplash trauma had weaker attachment to labour market (more weeks of sick leave (χ2(2) = 36.7, p < 0.001) and unemployment (χ2(2) = 12.5, p = 0.002)) pre-collision compared with controls. Experiencing a whiplash trauma raised the odds for future negative change in provisional situation (OR (95%CI) = 3.1 (2.3;4.4)) compared with controls. CONCLUSIONS: Sick leave before the collision strongly predicted prolonged recovery following whiplash trauma. Participants with acute whiplash trauma had weaker attachment to labour market pre-collision compared with the general population. Neck pain at inclusion predicted future neck pain. Acute whiplash trauma may trigger pre-existing vulnerabilities increasing risk of developing whiplash-associated disorders.

The influence of psychosocial factors on recovery following acute whiplash trauma.

Persistent pain and disability after whiplash trauma has become an increasingly significant problem in many industrialized countries entailing comprehensive individual as well as social costs. The dissertation includes two areas of research within whiplash trauma. The first part contains two empirical articles focusing on risk factors for poor recovery. The second part contains a systematic review and an empirical article and concerns the influence of coping strategies on recovery with a special emphasis on possible gender differences. All empirical articles in the dissertation are based on self-reported questionnaire data on a patient cohort of whiplash-exposed. Patients are consecutively included in the study within the first ten days of collision recruited from emergency departments and general practitioners in four counties in Denmark from April 2001 to June 2003. One of the empirical articles in the dissertation is supplemented with data from a social register of transfer benefits on the patient cohort as well as on a matched register control cohort in the general population. In this dissertation we wish to answer the following questions: 1) Do self-reported pre-collision health-related and socio-demographic factors affect self-reported work capability and neck pain one year after acute whiplash trauma? 2) Do transfer benefits before the accident predict negative change in future health-related provisional situation and future neck pain? 3) Do persons with acute whiplash trauma experience more negative change in future health-related provisional situation compared to a matched register control group? 4) Does research in the use of coping strategies after whiplash trauma show that these predict poor restitution and is there any research on gender differences in the use of coping strategies in whiplash-exposed? 5) Do gender and coping strategies interact in the prediction of future neck pain following acute whiplash trauma? Self-reported unspecified pain, female gender, low educational level, unemployment and blue collar work before the collision predicted future self-reported affected work capacity. Pre-collision self-reported unspecified pain, high psychological distress, female gender and low educational level predicted future self-reported neck pain. Self-reported characteristics before the collision are shown to be important for recovery after acute whiplash trauma. Whiplash exposure was a major risk factor for future negative change in provisional situation as whiplash-exposed more than tripled their risk of negative change in provisional situation compared to matched controls in the general population. Being unemployed, sick-listed, and receiving social assistance pre-accident were all associated with future negative change in health-related provisional situation. Sick-listing before the accident not only predicted negative change in provisional situation, but future neck pain as well. Furthermore, as few as 1-18 weeks of sick-listing within the five years preceding the collision more than doubled the risk of future negative provisional situation. Coping strategies are shown to affect recovery after whiplash trauma, but little information is available about which strategies are adaptive or maladaptive at different times in recovery. However, there is evidence of catastrophizing and reinterpreting pain sensations being maladaptive for patients exposed to whiplash trauma. There was not enough evidence to draw conclusions on the possible impact of gender in the use of coping strategies in patients exposed to whiplash trauma as only six studies contributed with findings, and only two studies treated the subject at some length. No interaction between gender and the five examined coping subscales on future neck pain were found. That is, use of coping strategies three months post-collision did not explain the different prognosis observed in men and women. However, we found that distraction, reinterpreting, catastrophizing, and praying and hoping predicted future considerable neck pain in both men and women. In conclusion, we propose that a complicated interrelationship of various factors before the collision constitutes a pre-disposing vulnerability that may be triggered by the whiplash trauma and act together with multifactorial maintaining factors after the accident in the course of developing persistent pain and disability after whiplash trauma. The findings from our study will make for further research and promote identification of patients at risk and hopefully contribute to preventive interventions and treatment that may decrease impairment in health-related quality of life and persistent symptoms and prevent the social decline that is a risk for some whiplash-exposed. This will in turn result in reduced social and economical costs not only for the individual, but also for society.

[Pre-collision pain and psychological distress predict poor outcome following acute whiplash trauma--secondary publication]. / Smertetilstand og psykologisk distress før uheldet praedikterer gener efter whiplash-traume--sekundaerpublikation.

Patients with acute whiplash trauma were followed to examine if pre-collision pain and psychological distress were associated with reduced work capability and neck pain at 12 month follow-up. Pre-collision unspecified pain was associated with reduced work capability, and neck pain and pre-collision psychological distress was associated with neck pain. In conclusion unspecified pain (as opposed to specified pain) and high accumulation of pre-collision psychological distress (as opposed to a single psychological disorder) before the collision was associated with poor recovery at follow-up.