Prognostic value of duration of illness and early intervention in bulimia nervosa: a systematic review of the outcome literature

OBJECTIVE: Early intervention is often regarded as an important step for the prevention of a chronic eating disorder. The primary aim of this review was to systematically evaluate the outcome literature and to better describe the effects of early intervention on the course of bulimia nervosa.

METHOD: Twenty-four follow-up studies were subjected to nine "best-evidence" criteria for methodological soundness. Of these 24 studies, 5 met all methodological criteria and were considered in more detail.

RESULTS: Only one of these five studies found a significant association between duration of illness and outcome. These studies were re-examined to exclude studies that included patients who were not first admissions in order to distinguish between the effect of duration of illness versus early intervention. This re-examination excluded four of the five studies, and the remaining study provided no data regarding prior treatment.

DISCUSSION: Based on this selection of studies, it was concluded that there is no consistent evidence to support that early intervention necessarily implies a better long-term outcome. Due to the multiple methodological problems that plague follow-up studies, future research would be improved by employing designs that directly test the impact of early versus late intervention.