Objectives: To report on long-term trends in hospital admission rates for anorexia nervosa using two English datasets. Design: We used data on hospital day-case and inpatient care across five decades in the Oxford Record Linkage Study (ORLS), and similar data for all England from 1990. We analysed rates of admission for anorexia nervosa in people aged 10-44 years, using hospital episodes (counting every admission) and first-recorded admissions (counting only the first record for each person). Setting: Former Oxford NHS Region; and England. Participants: None; anonymous statistical records were used. Results: In the longstanding ORLS, the age-standardised first-recorded admission rate for women was 2.7 (95% confidence interval 1.6-3.8) per 100,000 female population aged 10-44 years in 1968-1971; 2.7 (2.1-3.3) in 1992-1996; and 6.3 (5.5-7.2) in 2007-2011. Male rates were zero in the 1960s; 0.07 (0.0-0.1) per 100,000 men in 1992-1996; and 0.4 (0.2-0.6) in 2007-2011. In England, female rates increased from 4.2 (4.0-4.4) in 1998-2001 to 6.9 (6.7-7.1) in 2007-2011; and the corresponding male rates were 0.2 (0.1-0.3) and 0.5 (0.4-0.6). Episode-based admission rates rose more than person-based rates. The highest rates by far were in girls and women aged 15-19 years. Conclusions: In recent years, anorexia nervosa has become a greater burden on secondary care: not only have admission rates increased but so too have multiple admissions per person with anorexia nervosa. The increase in admission rates might reflect an increase in prevalence rates of anorexia nervosa in the general population, but other explanations, including lower clinical thresholds for admission, are possible and are discussed.
KeywordsAnorexia nervosa, eating disorders, admission rates, hospital trends, mortality rates Anorexia nervosa (AN) is an eating disorder characterised by a distorted body image with a pathological fear of becoming fat, leading to extreme weight loss and low body mass index (<17.5 kg/m 2 ). It is more common in women than men: in a review of 29 cross-sectional surveys, it was stated that 'its incidence is about ten times higher in females than males'.1 A survey in the USA found a smaller female-to-male difference: the authors reported a total estimated lifetime prevalence of 0.6%, with 0.9% for women and 0.3% for men.2 These authors suggested that sex differences may not be as pronounced as previously thought because of greater reluctance of men than women to seek help.2 anorexia nervosa has a very variable course and prognosis: less than half of all patients fully recover, one-third improve with only residual symptoms and 20% follow a chronic course.3 The all-cause age-standardised mortality ratio (SMR) in young people with anorexia nervosa has been estimated at 10 (relative to SMR ¼ 1 in the general population of equivalent age), which is about three times higher than that of other psychiatric disorders. 4,5