Physical symptoms that are frequently unexplained among survivors of the Enschede fireworks disaster

Most studies after disasters have focused on mental health problems such as post-traumatic stress disorder (PTSD), depression and anxiety among survivors. Besides mental health problems, survivors may develop physical health symptoms that are frequently unexplained such as headache, fatigue and stomachache as a result of the traumatic event. To date, these symptoms have not often been studied after disasters. The studies described in this thesis examine symptoms that are frequently medically unexplained among residents affected by the Enschede fireworks disaster. As a result of the explosion of a fireworks depot in a residential area in Enschede, the Netherlands, 23 persons were killed, more than 900 people were injured and about 1200 people were forced to relocate because their houses were destroyed or severely damaged. After this disaster, a longitudinal study of the health consequences of the disaster was started. The study consisted of a 3-wave longitudinal health survey that was performed three weeks (wave 1), 18 months (wave 2) and almost 4 years (wave 3) after the disaster. In addition to this longitudinal health survey, the electronic medical records (EMRs) of general practitioners (GPs) were used to study changes in health problems among survivors. The main objectives of this thesis were 1) to examine the prevalence of symptoms among survivors of disasters, 2) to explore risk factors for these symptoms among survivors and 3) to investigate whether self-reported symptoms show similarities with medically unexplained symptoms (MUS) that are presented to the GP. A review of the literature showed that the prevalence rate of self-reported symptoms was elevated among survivors of different kinds of disasters. Among the survivors of the fireworks disaster, the level of self-reported symptoms was higher compared to controls up to four years after the disaster. Besides this, the mean number of symptoms presented to the GP was higher in the two years after the disaster compared to the year prior to the disaster. We identified several important risk factors for symptoms among survivors such as female gender, immigrant status and psychological problems. The risk factors for physical symptoms among survivors were comparable with the risk factors for MUS in the general population. In addition, the results showed several similarities between the self-reported symptoms and MUS presented to the GP such as associated functional impairment and a higer level of illness behavior. Several methodological issues, such as the design, selective response and possible bias are discussed. Besides this, the advantages and disadvantages of the use of questionnaires and EMRs in epidemiological studies after disasters are discussed. The findings indicate that elevation of physical symptoms are part of the distress reaction following traumatic exposure. For that reason, it is recommended to measure these symptoms in studies after disasters. Also, since the self-reported symptoms showed several similarities with MUS, it can be concluded that questionnaires can be used to measure physical symptoms that are frequently unexplained