Although decades of research have transformed critical care medicine, important questions remain about why certain treatments are more effective for some patients than others and how proven interventions can be more consistently incorporated into clinical practice.

At Johns Hopkins Medicine, Chad Hochberg, assistant professor in the Division of Pulmonary and Critical Care Medicine, is helping address these questions through his involvement with the Common Longitudinal ICU Data Format (CLIF) Consortium.

Established in 2023, CLIF brings together researchers from academic health systems to strengthen the evidence guiding patient care in order to improve delivery of existing effective treatments and bring new research findings to the bedside.

Connecting Data, Strengthening Research

Although hospitals already collect extensive information about critically ill patients, they typically do not share that data to generate insights about patient care. CLIF addresses this challenge by establishing a common format for clinical information relevant to critical care, including vital signs, laboratory results, medications and respiratory supports such as mechanical ventilation. Rather than transferring individual patient records between institutions, participating investigators analyze information locally and share aggregated findings, an approach known as federated research.

For Hochberg, who serves as CLIF's vice chair of new member integration, the collaboration has significantly expanded opportunities to study critical illness. The consortium had grown from its original eight participating health systems to 14, representing roughly 80 hospitals. In his leadership role in CLIF, Hochberg helps new institutions adopt the standardized format and participate in collaborative investigations, expanding the network's capacity to examine complex clinical questions.

Theodore "Jack" Iwashyna, Bloomberg Distinguished Professor of Social Science and Justice in Medicine, is another Johns Hopkins participant with CLIF, serving on its senior advisory committee. A critical care physician and health services researcher, Iwashyna studies the lasting consequences of critical illness, including how conditions such as sepsis can affect patients' physical and cognitive functioning long after hospitalization. His expertise in patient outcomes and recovery complements Hochberg's focus on treatment practices, reinforcing the importance of understanding how patient care in the ICU may influence their lives after discharge.

The consortium's approach builds on existing Johns Hopkins Medicine research infrastructure, including an acute care registry developed through the Precision Medicine Center of Excellence in Critical Illness and Recovery. By connecting this work with investigators across North America, researchers can examine differences in treatment practices, identify opportunities for improvement, and generate findings that extend beyond a single hospital system. This broader perspective is valuable in intensive care units where treatment decisions often depend on complex clinical circumstances and rapidly changing patient conditions.

Turning Research into Better Care

One important application of CLIF involves research about acute respiratory distress syndrome (ARDS), a life-threatening condition in which inflammation and fluid in the lungs interfere with oxygen exchange. ARDS can develop following severe infections, trauma or critical illnesses. Patients frequently require mechanical ventilation, and identifying effective approaches to respiratory support remains a major priority in critical care research.

Hochberg recently led a CLIF-based multicenter study examining prone positioning, a potentially life-saving intervention in which mechanically ventilated patients are placed on their stomachs to improve oxygenation. Published in Critical Care Medicine, the study evaluated 5,944 eligible patients across 37 North American hospitals and identified substantial changes in treatment practices during and after the COVID-19 pandemic. Prone positioning increased from 11% of eligible patients before the pandemic to 51.9% during the pandemic, before declining to 25.6% afterward, despite established evidence supporting its use in patients with severe acute respiratory distress syndrome (ARDS).

These findings highlight an important challenge in critical care medicine: translating established clinical evidence into consistent, everyday practice. Although prone positioning is a recommended intervention for eligible patients with severe ARDS, the decline in its use suggests that improvements in treatment practices are not always sustained. By examining trends across multiple hospitals, CLIF allows researchers to identify variations in care and better understand opportunities for improvement. For Hochberg, whose research focuses on mechanical ventilation and implementing evidence-based practices, these insights can guide strategies to ensure effective treatments are more consistently delivered to patients who may benefit from them.

Expanding the Impact of Critical Care Research

The potential applications of CLIF extend beyond individual hospitals and health systems, offering a foundation for more consistent, evidence-based critical care worldwide. As the consortium grows, its standardized approach to clinical data could eventually support collaboration across international health systems, including military medical facilities.

As CLIF expands, Hochberg is also collaborating with investigators at the Johns Hopkins Bloomberg School of Public Health to develop statistical methods that support advances in federated data analysis — where insights are generated from pooled information summarized across institutions. These efforts aim to strengthen researchers' ability to evaluate relationships between treatments and patient outcomes while accounting for the many factors that influence recovery and while also preserving data integrity and patient privacy by keeping all source data within the host institutions. Such approaches are especially valuable when randomized clinical trials are difficult to conduct, allowing investigators to generate meaningful evidence from routinely collected clinical information.

Looking ahead, the consortium is exploring ways to translate research findings into practical tools for clinicians, including reports that help ICU leaders better understand treatment patterns within their own units. These tools could eventually allow hospitals to identify variations in care, evaluate adherence to evidence-based practices, and recognize opportunities for improvement. Although critical care must always account for individual patient needs and available resources, the long-term vision is one in which shared clinical evidence supports greater consistency in treatment across health systems and geographic boundaries.