A retrospective review of anorexia nervosa patients admitted to a specialised eating disorders inpatient unit comparing clinical and demographic characteristics of subtypes
Anorexia nervosa is a debilitating illness with the highest mortality rate of all psychiatric illnesses. Subtyping the illness into anorexia nervosa restricting subtype (AN-R) and anorexia nervosa binge-eating/purging subtype (AN-BP) has been a contentious issue since the inception of this subclassification in the 1994 DSM-IV. It has been proposed that there is little difference between the two subgroups and that categorising this eating disorder is of little utility and validity. The aim of this study was to compare the characteristics of a group of anorexic nervosa patients admitted to a specialised inpatient eating disorders unit in Johannesburg, South Africa, to investigate the differences, if any, between the AN-R and AN-BP groups. The hypothesis was that there are aspects of the subtypes which differ and therefore validate the delineation of anorexia nervosa into the two subgroups. The study sample consisted of 59 patients admitted to a specialised inpatient eating disorders unit with the diagnosis of anorexia nervosa, between January 2001 and December 2002. The study group was separated according to their sub-specific anorexia nervosa diagnosis: the AN-R sample (n=32) and the AN-BP sample (n=27). Various demographic and clinical features were reviewed. This study’s only significant result was the difference between the mean percentage of goal weight on admission between the two subtypes, with the average in the AN-R group being lower than that found in the AN-BP group (p-value=0.039). This study therefore does not provide sufficient evidence for the subclassification of anorexia nervosa. It is noted that a small sample size, inaccurate record-keeping and the possibility of diagnostic crossover may have influenced the outcome of this study.
A research report submitted to the Faculty of Medicine, Department of Psychiatry, University of the Witwatersrand in partial fulfilment for the degree of Master of Medicine (Psychiatry) Johannesburg 2015