The objective of this observational study is to estimate the number of weeks of welfare benefits, i.e. sickness benefit, unemployment benefit and social assistance, for individuals with functional somatic disorders and compare them to

1. healthy individuals, and
2. individuals with severe physical disease.

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 (1). The conditions may cause severe impairment for the patients who present with reduced physical and mental health, lower social status, and poor labour market association (2-4).

In 2005, it was estimated that FSD accounted for 3% of hospitalizations and 10-20% of health care expenses in Denmark (5), and a newer Danish primary care study has shown patients with FSD to have higher annual health care costs compared with conventionally-defined conditions (6). In other countries, studies in clinical samples have shown increased direct and indirect health care costs of FSD (7, 8) showing a dose-response relationship with severity of the FSD (9). These studies into highly selected clinical samples may induce high risk of selection bias, and studies including random selected general population samples are therefore needed. One Canadian population-based study on health care costs of children, adolescents, and young adults with FSD also found increased health care use and costs for this group (10). Studies investigating the socioeconomic burden in terms of welfare benefits of FSD in an adult random sample from the general population are, however, lacking.

Objective To estimate the number of weeks of welfare benefits, i.e. sickness benefit, unemployment benefit and social assistance, for individuals with FSD and compare them to individuals without FSD and individuals with severe physical disease.

Inclusion Criteria:

• None

Exclusion Criteria:

• Not born in Denmark
• Not being a Danish citizen
• Pregnancy

Participants were randomly drawn from the adult general Danish population by means of the the Danish Civil Registration system.

The DanFunD baseline cohort comprises a total of 9,656 (33.7% of invited participants) men and women aged 18-76 years, born in Denmark, and living in the Western part of greater Copenhagen. All participants filled in questionnaires regarding physical symptoms and psychological factors, among others. A stratified subsample (n=2,450) of every tenth participant and every symptom high score participant on the DanFunD baseline symptom questionnaires were invited to participate in a diagnostic interview, the Research Interview for Functional somatic Disorders (RIFD), performed by trained family physicians (28); 1,590 (64.9%) accepted and participated in the interview.