The incidence and prevalence of anorexia nervosa in three suburban health districts in south west London, U.K.

OBJECTIVE

To determine incidence and prevalence of anorexia nervosa in a defined geographical area of south west London, UK, total population 519,900.

METHOD

Hospital and community health workers in the defined area were contacted initially by letter asking them to identify all cases (new or existing) of anorexia nervosa known to them in the period July 1991-June 1992, using DSM-III-R criteria. A semistructured interview was conducted with the respondents to confirm the diagnosis. The large database record of the senior authors' specialist anorexia nervosa service, including inpatient and outpatient service records, was concurrently screened for cases living in the defined area.

RESULTS

The prevalence of anorexia nervosa was found by this method to be 20.2 cases per 100,000 population (0.02% total population). Prevalence in females aged 15-29 years was 115.4 cases per 100,000 (0.1% of young females). Similarly, the annual incidence of anorexia nervosa was found to be 2.7 cases per 100,000 total population. In females aged 15-29 years the incidence was 19.2 cases per 100,000.

DISCUSSION

Such prevalence and incidence figures are probably significant underestimates since the disorder can often defy detection or correct diagnosis and, with our own methodology, some identified cases may not have been reported to the study. However, these results can be used as a start for resource planning and service development.