Clinical components and associated behavioural aspects of a complex healthcare intervention: Multi-methods study of selective decontamination of the digestive tract in critical care

BACKGROUND: This study sought to identify and describe the clinical and behavioural components (e.g. the what, how, when, where and by whom) of 'selective decontamination of the digestive tract' (SDD) as routinely implemented in the care of critically ill patients. METHODS: Multi-methods study, consisting of semi-structured observations of SDD delivery, interviews with clinicians and documentary analysis, conducted in two ICUs in the UK that routinely deliver SDD. Data were analysed within-site to describe clinical and behavioural SDD components and synthesised across-sites to describe SDD in context. RESULTS: SDD delivery involved multiple behaviours extending beyond administration of its clinical components. Not all behaviours were specified in relevant clinical documentation. Overall, SDD implementation and delivery included: adoption (i.e. whether to implement SDD), operationalisation (i.e. implementing SDD into practice), provision (i.e. delivery of SDD) and surveillance (i.e. monitoring the ecological effects). Implementation involved organisational, team and individual-level behaviours. Delivery was perceived as easy by individual staff, but displayed features of complexity (including multiple interrelated behaviours, staff and contexts). CONCLUSIONS: This study is the first to formally outline the full spectrum of clinical and behavioural aspects of SDD. It identified points in the delivery process where complex behaviours occur and outlined how SDD can be interpreted and applied variably in practice. This comprehensive specification allows greater understanding of how this intervention could be implemented in units not currently using it, or replicated in research studies. It also identified strategies required to adopt SDD and to standardise its implementation.