Intensive care unit exposures for long-term outcomes research: Development and description of exposures for 150 patients with acute lung injury

Purpose: Long-term follow-up studies in critical care have described survivors' outcomes, but provided less insight into the patient/disease characteristics and intensive care therapies ("exposures") associated with these outcomes. Such insights are essential for improving patients' long-term outcomes. This report describes the development of a strategy for comprehensively measuring relevant exposures for long-term outcomes research, and presents empiric results from its implementation. Materials and Methods: A multistep, iterative process was used to develop the exposures strategy. First, a comprehensive list of potential exposures was generated and subsequently reduced based on feasibility, redundancy, and relevance criteria. Next, data abstraction methods were designed and tested. Finally, the strategy was implemented in 150 patients with acute lung injury with iterative refinement. Results: The strategy resulted in the development of more than 60 unique exposures requiring less than 45 minutes per patient-day for data collection. Most exposures had minimal missing data and adequate reliability. These data revealed that evidence-based practices including lower tidal volume ventilation, spontaneous breathing trials, sedation interruption, adequate nutrition, and blood glucose of less than 6.1 mmol/L (110 mg/dL) occurred in only 23% to 50% of assessments. Conclusions: Using a multistep, iterative process, a comprehensive and feasible exposure measurement strategy for long-term outcomes research was successfully developed and implemented.