Stephan

Ehrhardt

,

MD

My research interests include clinical trial methodology, in particular the design, conduct, and analysis of randomized clinical trials (RCT). Specifically, I am involved in developing methods to estimate more precise treatment effects across subgroups of study participants. RCT generally focus on estimating the average treatment effect of an intervention across the study sample. We aim to use prognostic data to determine individual randomization probabilities to increase external validity of RCTs, allow for estimation of complex treatment heterogeneity, potentially improve outcomes in study participants in the control arm, and improve the acceptability of RCTs to study participants while minimizing the loss of power in estimating the average treatment effect.

I design, lead, and co-lead flexible and methods-driven Data Coordinating Centers (DCC) for large and complex multicenter clinical trials across a variety of content areas.

For example, ENRICH is a multicenter, cluster-randomized trial evaluating a new home visiting-based intervention to improve cardiovascular health (CVH) in pregnant people and their offspring. Poor CVH contributes greatly to maternal morbidity and mortality in the United States, and many families enrolled in home visiting are at risk for poor CVH.  Improving CVH requires focusing on CVH risk factors, 2-generation strategies addressing mothers and children, and greater use of settings where families already receive care.  The Johns Hopkins Early Intervention to Promote Cardiovascular Health of Mothers and Children (ENRICH) Resource and Coordinating Center (RCC) will generate rigorous, innovative, timely and actionable new knowledge to promote CVH and reduce CVH disparities in mothers and young children.

Another current project is the Clean Air 2 DCC. COPD is a leading cause of death and morbidity worldwide and is attributable to the aggregate burden of toxic gases and particles that individuals inhale during their lifetime. Particulate matter (PM) and nitrogen dioxide (NO2) are common pollutants in indoor environments where adults with COPD spend >90% of their time. In a Phase III multi-center randomized sham-controlled trial we are testing the effectiveness of an air cleaner intervention targeting indoor pollutants (PM and NO2) on quality of life and exacerbation risk reduction among former smokers with COPD (n~770) across multiple clinical practice locations.

Other areas of interest include neurology and gastroenterology. I have worked across a variety of settings in both high- and low-income countries and am experienced in leading multi-country research projects.

Methodologic issues in observational network studies and consortia are of great interest in addition to the interventional work.

My research portfolio includes research ethics in multicenter studies.