Detection of eating disorders in a small rural town: an epidemiological study.

The occurrence of eating disorders among 517 school girls (11 to 20 years of age) in a small rural Italian town was studied using a three-stage prospective procedure. The screening stage was aimed at defining risk and sub-risk groups. One year later, the risk group (N = 44) and a random sample of the sub-risk (N = 25) and of the screen-negative group (N = 32) were interviewed to detect cases of anorexia/bulimia nervosa. The case registers of four hospitals over a period of 3 years were investigated to detect any additional cases that may have been overlooked in the survey. A minimum point prevalence rate of 1.30% clinical anorexia nervosa, 1.30% sub-clinical anorexia nervosa and 0.87% sub-clinical bulimia nervosa was found for age 15 and above. No case of clinical bulimia nervosa was detected. For age 15 and below no clinical or sub-clinical cases were found. All cases of (sub-)clinical eating disorder initially belonged to the predefined sub-risk and risk groups. Because of the low positive predictive value of any single risk factor, this study shows that early case detection can be improved by using multiple risk indices. In this rural area the prevalence was as high as in metropolitan or urban areas. Urban-rural differences should be assessed in further studies.