A Systematic review
Cognitive behaviour therapy compared to other psychotherapies for treatment of bulimia nervosa: a systematic review
Systematic review
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We have conducted a systematic review about the effect of cognitive behaviour therapy compared to other psychotherapies for treatment of bulimia nervosa. We have included 14 randomized controlled trials in total.
Key message
Bulimia nervosa is an eating disorder characterized by repeated episodes of binging where the binge eating is followed by behaviours to prevent weight gain. Bulimia nervosa affects approximately 2% of women between the ages of 14 and 44 years.
We have conducted a systematic review about the effect of cognitive behaviour therapy compared to other psychotherapies for treatment of bulimia nervosa. We have included 14 randomized controlled trials in total.
Cognitive behaviour therapy compared to other psychotherapies for people who suffer from bulimia nervosa:
- Probably leads to more people who stop binging and purging, a better mean bulimic symptom score, similar number of people dropping out of treatment and similar mean weight/ BMI at end of treatment (moderate certainty of the evidence)
- Possibly leads to similar improvement in general psychiatric symptoms and psychosocial/ interpersonal functioning at the end of treatment but there is considerable variation in scores between studies (low certainty of the evidence)
- There is very little information about drop out due to adverse events (very low certainty of the evidence)
Summary
Background
Bulimia nervosa is an eating disorder characterized by repeated episodes of binging where the binge eating is followed by behaviours to prevent weight gain. Bulimia nervosa affects approximately 2% of women between the ages of 14 and 44 years.
Objective
We have conducted a systematic review about the effect of cognitive behaviour therapy compared to other psychotherapies for the treatment of bulimia nervosa in persons over 16 years.
Method
We searched for randomized controlled trials in the following databases (November 2015): MEDLINE; Embase; Cochrane CENTRAL; PsycINFO; CINAHL, SveMed+, Web of Science, ClinicalTrials.gov and ICTRP World Health Organization.
Two persons assessed all references for inclusion independently of each other. All references considered potentially relevant were assessed in full text. Two persons independently evaluated the risk of bias in the included studies.
The relevant population was persons over 16 years who suffer from bulimia nervosa. Relevant interventions was cognitive behavioural therapy compared with other psychotherapies. One person extracted information and another person double-checked that the important and correct information were collected. We evaluated our confidence in the results using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation).
Results
We have included 14 randomized controlled trials in total. Cognitive behaviour therapy compared to other psychotherapies for people who suffer from bulimia nervosa:
- Probably leads to more people who stop binging and purging (RR 0.84 (95% CI 0.72 to 0.97)), a better mean bulimic symptom score (SMD -0.23 (95% CI -0.45 to -0.01)), similar number of people dropping out of treatment (RR 1.11 (95% CI 0.88 to 1.39)) and similar mean weight/ BMI at end of treatment (SMD -0.04 (95% CI -0.13 to 0.22)) (moderate certainty of the evidence)
- Possibly leads to improvement in mean depression score (SMD -0.36 (95% CI -0.71 to -0.02)), but there is considerable variation in peoples’ general psychiatric symptoms (low certainty of the evidence)
- Possibly leads to similar improvement in general psychiatric symptoms (SMD -0.18 (95% CI -0.55 to 0.18)) and psychosocial/ interpersonal functioning at the end of treatment (SMD -0.53 (95% CI -1.21 to 0.15) but there is considerable variation in scores between studies (low certainty of the evidence)
- There is very little information about drop out due to adverse events (very low certainty of the evidence)
Discussion
All of the 14 randomized controlled trials included in this systematic review were conducted in high-income countries. The trials were small, only between 14 and 293 persons in each trial, and most of the trials had an unclear risk of bias.
The methods of diagnosis and the criteria for the diagnosis of bulimia nervosa has been changing over time. Therefore, there were some variation in how serious the symptoms were among the people who took part in the different studies. The conclusion of the meta-analysis of the outcomes mean bulimic symptom scores and mean depression scores changed when conducted without the one study that only included people with the non purging type of bulimia. This clearly demonstrates the importance of the changing diagnostic criteria.
Conclusion
Cognitive behaviour therapy compared to other psychotherapies for people who suffer from bulimia nervosa probably leads to more people who stop binging and purging and a better mean bulimic symptom score at end of treatment.