Abstract
Background
High rates of attrition undermine the success of weight management interventions (WMIs), but a comprehensive understanding of the factors that increase dropout risk remains absent. This is partly explained by heterogeneity of intervention design, and the absence of a universal definition of attrition. This systematic review aimed to identify the factors related to- and predictive of attrition and retention in multidisciplinary WMIs for adults with obesity.
Methods
The systematic literature search, conducted in Cochrane, Medline, PsycInfo, and Scopus, aimed to identify original research articles published between February 2008 and December 2019. Articles investigating attrition or retention in multidisciplinary WMIs were eligible for inclusion if interventions were for adults (≥18) with obesity identified by body mass index ≥30kg/M2 and lasted ≥6 months. Multidisciplinary was defined as ≥2 interventionist disciplines or professions, for the purpose of this review. Data was synthesised narratively.
Results
The literature search resulted in seventeen studies which satisfied the inclusion criteria. Attrition rates ranged from 10% at 3-months to 81% at 3-years. The sociodemographic factors associated with reduced risk of attrition included older age, living in less deprived areas, higher levels of education, and female gender. Poor mental health, low social support, high weight loss goals and poor or unsatisfactory results may increase the likelihood of participant dropout, but evidence was limited and inconclusive because of different methodologies, and only a small number of studies investigating some of the variables.
Conclusions
The scope for targeted retention strategies is limited because few variables were consistently associated with attrition. Until a comprehensive understanding of attrition emerges, WMIs should seek to reduce social inequities in the benefit of WMI provision. Future research should consider factors reported qualitatively, such as intervention expectations and satisfaction, social support, patient-clinician relationships, and logistical barriers. Adopting a universal definition of attrition and de-homogenising participant dropouts would advance future research. As qualitative evidence is limited, exploring participant experiences of WMIs would help understand how attrition rates can be reduced, and in-turn improve WMI effectiveness.