Health Care Use and Costs of Functional Somatic Disorders

Study Overview
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Brief Summary
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The goal of this observational case-control study is to learn about direct healthcare use and costs of functional somatic disorders. The aim of the proposed study is to investigate the use and costs of direct healthcare for individuals with functional somatic disorders. Researchers will compare direct healthcare use and costs of individuals with functional somatic disorders and compare them with that of healthy controls and individuals with other severe physical disease, respectively.

Detailed Description
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Functional somatic disorders (FSD) are common conditions characterized by persistent patterns of physical symptoms that cannot be better explained by other physical or mental conditions. The conditions may cause severe impairment for the patients who are often characterized by impaired physical and mental health, lower social status, and poor labour market association. In 2005, it was estimated that FSD accounted for 3% of hospitalizations and 10-20% of health care expenses in Denmark, and a newer Danish primary care study has shown patients with FSD to have higher annual health care costs compared with conventionally-defined conditions. In foreign nations, studies in clinical samples have shown increased direct and indirect health care costs of FSD which showed a dose-response relationship with severity of the FSD. One Canadian population-based study found increased health care use and costs in children, adolescents, and young adults with a first health record diagnosis of somatic symptom and related disorders. Even though these previous studies provide valuable knowledge to the field of FSD, their methodology may give rise to bias, i.e. inclusion of highly selected patient samples, the use of various diagnostic criteria for defining FSD, and the establishment of FSD by means of self-report. Evidently, studies investigating the socioeconomic burden in terms of direct health care use and costs of FSD in a randomly obtained population-based sample using solid methodology such as validated symptom criteria and diagnostic interviews for establishing FSD are highly lacking. The objectives of this proposed study are: To describe and investigate the healthcare use and healthcare costs for individuals with FSD and compare them with individuals without FSD, and individuals with severe physical disease

Official Title
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Health Care Use and Costs of Functional Somatic Disorders: A Population-based Study (DanFunD)

Conditions
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Bodily Distress Syndrome, Irritable Bowel, Fibromyalgia, Chronic Widespread Pain, Chronic Fatigue Syndrome

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: None Exclusion Criteria: not born in Denmark not being a Danish citizen pregnancy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 76 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| DanFunD baseline<br>Data from the DanFunD baseline cohort will be included. It comprises a total of 9,656 (33.7% of the invited participants) men and women aged 18-76 years born in Denmark and living in the Western part of greater Copenhagen. Individuals with FSD are identified by means of self-reported questionnaires (n=9,656) and diagnostic research interviews (n=1,590). Participants with FSD will be defined as follows: FSD operationalised by the Bodily Distress Syndrome single- and multi-organ type will be defined with both self-reported questionnaires and diagnostic interviews. Three functional somatic syndromes, i.e. irritable bowel, chronic widespread pain, and chronic fatigue will be defined with questionnaires. Severe physical disease will be defined by means of self-report as having received at least one of the following five diagnoses: Cancer, stroke, myocardial infarction, other heart disease, and obstructive pulmonary disease. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Use of primary healthcare resources 10 years before baseline | Data on use of healthcare in primary care will be extracted from the Danish National Health Service Register for Primary Care. This category will include number of face-to-face consultations in general practise, medical specialists, physiotherapists, chiropractors, and psychologists. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Costs of primary healthcare resources 10 years before baseline | Data on costs of healthcare in primary care will be extracted from the Danish National Health Service Register for Primary Care. This category will include number of face-to-face consultations in general practise, medical specialists, physiotherapists, chiropractors, and psychologists. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Use of primary healthcare resources 4 years after baseline | Data on use of healthcare in primary care will be extracted from the Danish National Health Service Register for Primary Care. This category will include number of face-to-face consultations in general practise, medical specialists, physiotherapists, chiropractors, and psychologists. | 4-year period after the day the participant participated in the DanFunD baseline investigation | 
| Costs of primary healthcare resources 4 years after baseline | Data on costs of healthcare in primary care will be extracted from the Danish National Health Service Register for Primary Care. This category will include number of face-to-face consultations in general practise, medical specialists, physiotherapists, chiropractors, and psychologists. | 4-year period after the day the participant participated in the DanFunD baseline investigation | 
| Use of secondary healthcare resources 10 years before baseline | Data on use of healthcare in secondary care will be extracted from the National Patient Registry. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Costs of secondary healthcare resources 10 years before baseline | Data on costs of healthcare in secondary care will be extracted from the National Patient Registry. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Use of secondary healthcare resources 4 years after baseline | Data on use of healthcare in secondary care will be extracted from the National Patient Registry. | 4-year period after the day the participant participated in the DanFunD baseline investigation | 
| Costs of secondary healthcare resources 4 years after baseline | Data on costs of healthcare in secondary care will be extracted from the National Patient Registry. | 4-year period after the day the participant participated in the DanFunD baseline investigation | 
| Use of prescription medication 10 years before baseline | Data on number of prescriptions will be extracted from The Danish Register Prescription Sales. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Costs of prescription medication 10 years before baseline | Data on costs of prescriptions will be extracted from The Danish Register Prescription Sales. | 10-year period before the day the participant participated in the DanFunD baseline investigation | 
| Use of prescription medication 4 years after baseline | Data on number of prescriptions will be extracted from The Danish Register Prescription Sales. | 4-year period after the day the participant participated in the DanFunD baseline investigation | 
| Costs of prescription medication 4 years after baseline | Data on costs of prescriptions will be extracted from The Danish Register Prescription Sales. | 4-year period after the day the participant participated in the DanFunD baseline investigation |