Analysing Complex Interventions Using Component Network Meta-Analysis

Systematic reviews with network meta-analysis frequently evaluate complex interventions combining multiple healthcare interventions (known as components). Components may act separately of each other or in conjunction with other components, synergistically or antagonistically. Component effect estimation is crucial to produce relevant and clinically meaningful evidence. However, standard network meta-analysis cannot quantify individual component effects of complex interventions. This article presents methods for modelling complex interventions and highlights the advantages and limitations of component network meta-analysis (CNMA). CNMA enables the estimation of individual component effects, whether additive or interactive. Interaction CNMA can be considered an extension of the additive CNMA model that allows component effects to vary in the presence of each other. This article presents practical guidance on how to carry out these analyses via empirical examples, which showcase both the strengths and limitations of CNMA. Implementing CNMA models is complex and requires the skills of a multidisciplinary team including clinicians, methodologists, and statisticians.