Predictors, mediators, and moderators of response to digital interventions for eating disorders: A systematic review

ObjectiveDigital interventions show promise as an effective prevention or self-management option for eating disorders (EDs). However, it remains unclear how, for whom, and through what mechanisms they work in this population, as a synthesis of outcome predictors, moderators, and mediators is lacking. This systematic review synthesized empirical research investigating predictors, mediators, and moderators of response to digital interventions for EDs.MethodSix databases were searched (PROSPERO CRD42022295565) for studies that assessed predictors, moderators, or mediators of response (i.e., uptake, drop-out, engagement, and symptom level change) to a digital prevention or treatment program for EDs. Variables were grouped into several overarching categories (demographic, symptom severity, psychological, etc.) and were synthesized qualitatively across samples without a formally diagnosed ED (typically prevention-focused) and samples with a formally diagnosed ED (typically treatment-focused).ResultsEighty-six studies were included. For studies recruiting samples without a formal diagnosis (n = 70 studies), most predictors explored were statistically unrelated to outcome, although participant age, baseline symptom severity, confidence to change, motivation, and program engagement showed preliminary evidence of prognostic potential. No robust moderators or mediators were identified. Few studies recruiting samples with a formal diagnosis emerged (n = 16), of which no reliable predictors, moderators, or mediators were identified.DiscussionIt remains unclear how, for whom, and under what circumstances digital programs targeting EDs work. We offer several recommendations for future research with the aim of advancing understanding of client characteristics and intervention elements that signal success from this intervention modality.Public SignificanceDigital interventions have shown potential as an effective, scalable, and accessible intervention option for EDs. However, responsiveness varies, so advancing understanding of predictors, mediators, and moderators of outcome to digital interventions for EDs is needed. Such knowledge is important for enabling safe and efficient treatment matching, and for informing future development of effective digital interventions. ObjetivoResultadosLas intervenciones digitales se muestran prometedoras como una opcion eficaz de prevencion o autocontrol de los trastornos de la conducta alimentaria (TCA). Sin embargo, sigue sin estar claro como, para quien y a traves de que mecanismos funcionan en esta poblacion, ya que falta una sintesis de los predictores de resultados, moderadores y mediadores. Esta revision sistematica sintetiza la investigacion empirica que estudia los predictores, mediadores y moderadores de la respuesta a las intervenciones digitales para los TCA.MetodoSe realizaron busquedas en seis bases de datos (CRD42022295565) de estudios que evaluaron predictores, moderadores o mediadores de la respuesta (es decir, admision, abandono, compromiso y cambio en el nivel de sintomas) a un programa digital de prevencion o tratamiento de los TCA. Las variables se agruparon en varias categorias generales (demograficas, gravedad de los sintomas, psicologicas, etc.) y se sintetizaron cualitativamente en muestras sin un TCA diagnosticado formalmente (normalmente centradas en la prevencion) y muestras con un TCA diagnosticado formalmente (normalmente centradas en el tratamiento).Se incluyeron 86 estudios. Para los estudios que reclutaron muestras sin un diagnostico formal (n = 70 estudios), la mayoria de los predictores explorados no estaban estadisticamente relacionados con el resultado, aunque la edad del participante, la gravedad de los sintomas basales, la confianza en el cambio, la motivacion y el compromiso con el programa mostraron evidencia preliminar de potencial pronostico. No se identificaron moderadores o mediadores solidos. Surgieron pocos estudios que reclutaran muestras con un diagnostico formal (n = 16), de los cuales no se identificaron predictores, moderadores o mediadores fiables.DiscusionSigue sin estar claro como, para quien y en que circunstancias funcionan los programas digitales dirigidos a los TCA. Ofrecemos varias recomendaciones para futuras investigaciones con el objetivo de avanzar en la comprension de las caracteristicas de los consultantes y los elementos de intervencion que senalan el exito de esta modalidad de intervencion.