From Framework to Toolkit: Practical Guidance for Using the PrOcess Evaluation of Trials In Critical care (POETIC) Framework

BACKGROUND: The PrOcess Evaluation of Trials In Critical care (POETIC) framework was developed to support systematic evaluation of Context, Fidelity, Dose, Reach, and an integrative assessment of Quality of Delivery (QoD). Its practical use, however, requires explicit guidance on selecting measures, constructing QoD, assessing changing context, and governing prospective use. METHODS: We undertook a retrospective comparative synthesis of process evaluations embedded in four randomized U.K. critical care trials: Biomarker-guided antibiotic stewardship in suspected ventilator-associated pneumonia (VAPrapid-2), Provision of Psychological Support to People in Intensive Care (POPPI), Sedation AND Weaning In CHildren (SANDWICH), and Alpha-2 agonists for sedation to produce Better outcomes from critical illness (A2B). We selected them because they informed POETIC's development or application and provided sufficiently detailed quantitative and qualitative evidence. We mapped the reports, protocols, and process evaluation findings to the five dimensions; compared recurring and contradictory patterns, quantitative-qualitative agreement, measurement and interpretation problems, and mechanism-specific limitations; and translated our learning into guidance for applying the framework. RESULTS: The relevance and measurement of POETIC dimensions varied according to how each intervention was expected to work. Contextual influences changed over time and differed between sites. Combined assessments of QoD required explicit decisions about component selection, weighting, thresholds, aggregation, and missing data. VAPrapid-2 showed why a separate Dose measure and a QoD composite were not meaningful for a one-off diagnostic recommendation; POPPI used a weighted site composite; SANDWICH summarized delivery of four intervention components, staff training, and patient Reach; and A2B combined four equally weighted indicators in a 0-12 site score. This cross-trial learning informed practical guidance on selecting measures, assessing context over time, integrating quantitative and qualitative findings, constructing QoD, and governing prospective use. CONCLUSIONS: POETIC is best used as a mechanism-aligned, mixed-method scaffold rather than a requirement to measure every dimension or calculate a universal composite. Prospective use is feasible when outputs, recipients, review times, permitted actions, and safeguards are prespecified. The framework and accompanying toolkit support reproducible assessment while protecting trial integrity.