Patterns of diagnostic transition in eating disorders: a longitudinal population study in Sweden

Abstract

Background: Transition across eating disorder diagnoses is common, reflecting instability of specific eating disorder presentations. Previous studies have examined temporal stability of diagnoses in adult treatment-seeking samples but have not uniformly captured initial presentation for treatment. The current study examines transitions across eating disorder diagnostic categories in a large, treatment-seeking sample of individuals born in Sweden and compares these transitions across two birth cohorts and from initial diagnosis.

Methods: Data from Swedish eating disorders quality registers were extracted in 2013, including 9622 individuals who were seen at least twice from 1999 to 2013. Patterns of remission were examined in the entire sample and subsequently compared across initial diagnoses. An older (born prior to 1990) and younger birth cohort were also identified, and analyses compared these cohorts on patterns of diagnostic transition.

Results: Although diagnostic instability was common, transition between threshold eating disorder diagnoses was infrequent. For all diagnoses, transition to remission was likely to occur following a diagnosis state that matched initial diagnosis, or through a subthreshold diagnostic state. Individuals in the younger cohort were more likely to transition to a state of remission than those in the older cohort.

Conclusions: Results indicate more temporal continuity in eating disorder presentations than suggested by previous research and highlight the importance of early detection and intervention in achieving remission.

Keywords: Anorexia nervosa; binge-eating disorder; bulimia nervosa; classification; crossover; diagnosis; eating disorders.

Figure 1.

Plot showing transitions among the eating disorders across the first three assessment points (A1-3). Size of the bubbles indicate the proportion of individuals presenting with each diagnosis, within each assessment point. The width of a line between two diagnoses represents the share of the total flow between two assessment points. AN = anorexia nervosa, BED = binge-eating disorder, BN = bulimia nervosa, ENDOS = eating disorder not otherwise specified, A1-A2: n = 9622, A3: n = 3499.

Figure 2.

Figure showing transition probabilities from diagnosis at Time X to diagnosis at Time Y for the full sample, controlling for number of visits. Arrows exogenous to each diagnosis indicate the likelihood of stability from Time X to Time Y (e.g. the likelihood of AN cases at Time X retaining an AN diagnosis at Time Y is .52). Bolded arrows pointing towards a diagnosis represent the likelihood of transition to that diagnosis at Time Y from the diagnosis where the arrow originates at Time X (e.g. the likelihood of AN cases at Time X transitioning to RM at Time Y is .21). AN = anorexia nervosa, BN = bulimia nervosa, BED = binge-eating disorder, EDNOS = eating disorder not otherwise specified; RM = remission.

Figure 3.

Heat map showing transitions among the eating disorders comparing younger and older cohorts. Ratios less than one indicate that transition is more likely in the younger cohort; ratios greater than one indicate that transition is more likely in the older cohort. AN = anorexia nervosa, BN = bulimia nervosa, BED = binge-eating disorder, ENDOS = eating disorder not otherwise specified; RM = remission.