Three decades of eating disorders in Dutch primary care: decreasing incidence of bulimia nervosa but not of anorexia nervosa

Background Whether the incidence of eating disorders in Western, industrialized countries has changed over time has been the subject of much debate. The purpose of this primary-care study was to examine changes in the incidence of eating disorders in The Netherlands during the 1980s, 1990s and 2000s. Method A nationwide network of general practitioners (GPs), serving a representative sample (similar to 1%) of the total Dutch population, recorded newly diagnosed patients with anorexia nervosa (AN) and bulimia nervosa (BN) in their practice during 1985-1989, 1995-1999, and 2005-2009. GPs are key players in the Dutch healthcare system, as their written referral is mandatory in order to get access to specialized (mental) healthcare, covered by health insurance. Health insurance is virtually universal in The Netherlands (99% of the population). A substantial number of GPs participated in all three study periods, during which the same case identification criteria were used and the same psychiatrist was responsible for making the final diagnoses. Incidence rates were calculated and for comparison between periods, incidence rate ratios. Results The overall incidence rate of BN decreased significantly in the past three decades (from 8.6 per 100 000 person-years in 1985-1989 to 6.1 in 1995-1999, and 3.2 in 2005-2009). The overall incidence of AN remained fairly stable during three decades, i.e. 7.4 per 1 00 000 person-years in 1985-1989, 7.8 in 1995-1999, and 6.0 in 2005-2009. Conclusions The incidence rate of BN decreased significantly over the past three decades, while the overall incidence rate of AN remained stable.