Zsa Zsa Weerts

General introduction 11 1 Rome IV diagnostic criteria 1 for IBS* Recurrent abdominal pain, on average: At least 1 day per week in the last 3 months Associated with 2 or more of the following: 4. Related to defecation 5. Associated with a change in frequency of stool 6. Associated with a change in form (appearance of stool) *Onset of symptoms at least 6 months prior to diagnosis Box 1.3 Rome IV diagnostic criteria for IBS, published in 2016. Prevalence and socioeconomic burden of IBS IBS is highly prevalent and occurs in 5-20% of the population, with variations due to differences in diagnostic criteria used and geographical areas investigated. Furthermore, it has been shown that women and young people are more often affected. 24 Although IBS is not associated with increased mortality, it has a major impact at societal level. The high prevalence, increased healthcare utilization, and loss in productivity in patients with IBS result in both high direct and indirect costs. IBS patients, for example, have more consultations with a medical professional regarding their IBS, receive more diagnostic investigations, and use more prescribed or over the counter drugs than patients without the IBS diagnosis. Total annual direct costs per patient were estimated to range between $742-7547 (USA), €567-862 (France), and €791 (Germany). 25,26 Moreover, because IBS is associated with various comorbidities, studies have shown that the majority of healthcare charges in IBS patients was in fact for non-GI medical conditions and not for IBS. 27,28 In addition, IBS patients are more likely to be both absent from work (absenteeism) and impaired in productivity during work (presenteeism), compared to non-IBS patients. 29 Prior studies have estimated annual indirect costs per patient with IBS, being $748 (in Canada), $335 (in the United Kingdom), and €995 (in Germany). 25,30 As healthcare systems differ between countries, findings from studies on healthcare costs are difficult to compare. In the Netherlands, the economic burden of IBS in the first three years after diagnosis was investigated by Flik et al. , using an insurance database. 31 They observed that direct costs increased with 486 and 2328 euro after IBS was diagnosed in primary versus secondary care, respectively. Further data from a societal perspective on costs for the Dutch situation are lacking.