Does level of motivation for change impact post-treatment outcomes in the eating disorders? Protocol for a systematic review with quantitative analysis.

BACKGROUND: Eating Disorders are highly prevalent and widespread mental health problems, with marked risk of chronicity and refractoriness to treatment. Affected individuals are hesitant to change their behaviours and therefore struggle to maintain motivation for therapy. This review aims to produce the first high-quality meta-analysis of the literature on the impact of level of motivation for change on post-treatment outcomes in anorexia nervosa, bulimia nervosa, binge-eating disorder, and other specified feeding or eating disorder (OSFED).

METHODS: A systematic review will be conducted using Cochrane library, Embase, MEDLINE, and PsychINFO. Research registrars and bibliographies of included articles will be screened, and experts will be contacted. The search strategy consists of terms related to eating disorders, motivation, and outcome. Randomized controlled trials, clinical controlled trials, time series, and before-after studies will be included. Participants will be adolescents and adults who are diagnosed with anorexia nervosa, bulimia nervosa, binge-eating disorder or OSFED and who are entering psychotherapy treatment. The predictor studied is defined as motivation for change at the beginning of treatment. The primary outcome will be an overall change in eating-disorder symptomatology at the end of treatment and at less than, and over 6-month follow-up. Other outcomes of interest include change in restricting, binging, and compensatory behaviours, change in shape, weight and eating concerns, change in psychiatric comorbidities, weight restoration, and dropout rates. Articles will be selected, data will be extracted, and the risk of bias will be assessed by independent reviewers using forms pre-created on Eppi-Reviewer 4 software. Results will be combined using a random-effects model. Studies of all sizes and qualities will be included in the analyses. Heterogeneity will be examined by funnel plot, Cochran's Q, and I2 statistic. Sensitivity analyses will be performed to account for clinical and methodological differences across studies.

DISCUSSION: This systematic review will help determine the predictive value of motivation for change on treatment outcomes in eating disorders.

TRIAL REGISTRATION: Our systematic review protocol is registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42016035285). All modifications will be available on the PROSPERO website, along with the dates, a description, and a justification.