Kristoffer Skaarup, MD, is affiliated with  Copenhagen University Hospital-Herlev and Gentofte in Denmark.

Kristoffer Skaarup, MD

Kidney Compass: Navigating Clinical Trials

Kidney Compass: NUDGE-CKD and the Power of Pragmatic Trials

, host Brendon Neuen, MBBS, PhD, is joined by Tor Biering-Sørensen, MD, MPH, PhD, and Kristoffer Skaarup, MD, to discuss the design, execution, and implications of the NUDGE-CKD trial—a landmark pragmatic study aimed at improving guideline-based care in 

The NUDGE-CKD trial tested whether low-cost digital “nudges”—letters sent to patients and their primary care physicians emphasizing evidence-based CKD therapies—could increase use of guideline-directed medical therapies (GDMT) for people with CKD. Using Denmark’s nationwide registries and E-box digital communication system, the team identified > 160,000 individuals with CKD and ultimately randomized nearly 20,000 patients into different trial arms.

Key findings showed a modest but meaningful increase in GDMT uptake among patients who received the nudges—particularly when both patients and GPs received communication. While the patient-only letters had little effect, the combined approach led to greater prescribing of key medications and improved risk factor control.

The episode also highlights how Denmark’s integrated national data systems make this kind of large-scale, fast, and cost-efficient research possible. Biering-Sørensen and Skaarup describe how trials like NUDGE-CKD can be designed and launched within weeks, thanks to the ability to rapidly identify target populations and deploy interventions nationwide with minimal burden on patients or clinicians.

Looking ahead, the team is applying this model to test continuous mailed treatments in a new decentralized heart failure trial and is preparing to launch their first fully remote phase 3 trial. They also share insights from an embedded recruitment experiment, showing that shorter invitation letters significantly improve trial participation—underscoring the value of optimizing every layer of the research process.

The episode closes with a call to action: as implementation science and pragmatic trials gain momentum, embedding randomization and leveraging real-world systems can offer causal answers to practical questions, helping close the evidence-practice gap in CKD and beyond.

 include AstraZeneca, Bayer, Boehringer Ingelheim, Janssen, and others. Relevant disclosures for 

 include Amgen, Boston Scientific, Sanofi Pasteur, Novartis, and others. 

Podcasts

Host Brendon Neuen is joined by guests Tor Biering-Sørensen and Kristoffer Skaarup to discuss NUDGE-CKD and implementation trial design.

Kristoffer Skaarup, MD

Articles