Nationwide Utilization of Danish Government Electronic Letter System for Increasing Guideline-directed Medical Therapy in Chronic Kidney Disease (NUDGE-CKD)

September 26, 2025 updated by: Tor Biering-Sørensen

Kidney Disease Improving Global Outcomes (KDIGO) has recently updated the Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (CKD). This update follows large placebo-controlled randomized trials, which established sodium-glucose cotransporter 2 inhibitors (SGLT2i) as an additional treatment option to reduce the risk of progression to kidney failure and cardiovascular disease in patients with CKD, both with and without diabetes or albuminuria. As a result, SGLT2i is now recommended to a broad range of CKD patients by KDIGO, along with established medical therapies such as renin-angiotensin system inhibition (RASi). Despite the significant adverse consequences of CKD and substantial evidence supporting guideline-directed medical therapy (GDMT) to improve patient outcomes, awareness of CKD among patients and providers remains disproportionately low. Innovative solutions are needed to increase awareness of CKD. Such a solution could potentially be the use of electronic nudge letters delivered to patients with CKD and their general practitioners (GPs) that highlight the importance of GDMT and inform them of updated guidelines.

This study will investigate whether digital nudge letters delivered via the official Danish electronic letter system directly to patients with CKD and their associated GPs will improve GDMT in patients with CKD when compared to no letters.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The study is a prospective, 2x2 factorial, registry-based, randomized, open-label implementation trial. The study population will consist of Danish adults diagnosed with CKD. Participants will be identified through Danish nationwide health registries using codes from the International Classification of Diseases, 10th revision (ICD-10).

The primary objective of this study is to investigate the effects of electronically sent nudging letters delivered directly to (1) patients with CKD and, separately, (2) electronically sent nudge letters delivered to GPs of the included CKD patients on the primary outcome of use of GDMT defined as at least one prescription of RASi or SGLT2i 6 months after intervention delivery in patients with CKD.

Patients with CKD will be randomized (1:1) to either a control arm (no digital nudge letters sent to the patient) or an intervention arm (a digital nudge letter). GPs of the enrolled patients with CKD will be randomized (1:1) to a control arm (no digital nudge letters sent to the GP) or an intervention arm (a digital nudge letter). The letters will inform the recipients about the importance of GDMT in CKD and that updated Danish guidelines for treating CKD are available. The letter to the GPs will also include the definition of CKD and a summary of the guidelines.

The interventions will be delivered through the official, mandatory Danish electronic letter system. All subject data will be retrieved from the Danish nationwide registries except for information on intervention allocation. Endpoints will be retrieved at prespecified dates using prespecified search algorithms.

This study will coincide with the release of the updated clinical guidelines on the treatment of CKD by the Danish Society of Nephrology.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
28388

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Denmark
    • Capital Region
      • Hellerup, Capital Region, Denmark, 2900
        • Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion criteria

  1. Age +18 years
  2. Diagnosis of CKD defined as at least one hospital encounter with the following ICD-10 codes in the primary diagnostic positions within ≤ 5 years: N18- N19, I12, E102, E112, E132, E142.

Exclusion criteria

For patient-level intervention comparisons:

1) Exemption from the official, mandatory Danish electronic mailbox system.

For general practice-level intervention comparisons:

  1. Individuals on a patient list of general practice clinics run by Danish administrative Regions.
  2. Individuals not on a patient list of a general practice.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Patient letters + no GP letter.

Patients with CKD will receive digital nudge letters, but their associated GPs will not receive a digital nudge letter.

The letters will inform patients with CKD of the importance of GDMT in CKD and that updated Danish guidelines for the treatment of CKD are available.
Behavioral: Electronically delivered nudging letters to patients with CKD

Patients in the active arm will receive a digital nudge letter as part of the study. The nudge letter will be delivered at baseline. Letters will be delivered through the official, mandatory Danish electronic letter system.

The control arm will consist of patients with CKD randomized to not receive digital nudge letters (usual care).

Other Names:
  • Patient letters
Experimental: Patient letters + GP letter.

Patients with CKD and their associated GPs will receive digital nudge letters.

The letters will inform the recipients of the importance of GDMT in CKD and that updated Danish guidelines for the treatment of CKD are available. The letter to the GPs will also include the definition of CKD and a summary of the guidelines.
Behavioral: Electronically delivered nudging letter to associated GPs of patients with CKD

The associated GPs of the patients in the active arm will receive one digital nudge letter as part of the study. The nudge letter will be delivered at baseline. The letters will be delivered through the official, mandatory Danish electronic letter system.

The control arm will consist of patients with CKD whose associated GP was randomized to not receive a digital nudge letter (usual care).

Other Names:
  • GP letter
Behavioral: Electronically delivered nudging letters to patients with CKD

Patients in the active arm will receive a digital nudge letter as part of the study. The nudge letter will be delivered at baseline. Letters will be delivered through the official, mandatory Danish electronic letter system.

The control arm will consist of patients with CKD randomized to not receive digital nudge letters (usual care).

Other Names:
  • Patient letters
Experimental: No patient letters + GP letter

Patients with CKD will not receive digital nudge letters, but their associated GPs will receive a digital nudge letter.

The letter will inform the GPs of the importance of GDMT in CKD and that updated Danish guidelines for the treatment of CKD are available. The letter will also include the definition of CKD and a summary of the guidelines.
Behavioral: Electronically delivered nudging letter to associated GPs of patients with CKD

The associated GPs of the patients in the active arm will receive one digital nudge letter as part of the study. The nudge letter will be delivered at baseline. The letters will be delivered through the official, mandatory Danish electronic letter system.

The control arm will consist of patients with CKD whose associated GP was randomized to not receive a digital nudge letter (usual care).

Other Names:
  • GP letter
No Intervention: No patient letters + no GP letter
Neither patients with CKD nor their associated GPs will receive digital nudge letters.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Number of participants with any prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Number of participants with any prescription of renin-angiotensin system inhibition
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of renin-angiotensin system inhibition
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months
Time from intervention delivery to a new prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months
Time from intervention delivery to a new prescription of renin-angiotensin system inhibition
Time Frame: within 6 months
within 6 months
Time from intervention delivery to a new prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Time Frame
Number of participants with an increase in baseline daily RASi dosage
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of mineralocorticoid receptor antagonists
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of non-steroid mineralocorticoid receptor antagonists
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of cholesterol-lowering medication
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of glucagon-like peptide-1 analogue
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of antidiabetic medication besides SGLT2i
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of antidiabetic medication
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of antihypertensive medication besides renin-angiotensin system inhibition
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of antihypertensive medication
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of mineralocorticoid receptor antagonists
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of non-steroid mineralocorticoid receptor antagonists
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of cholesterol-lowering medication
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of glucagon-like peptide-1 analogue
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of antidiabetic medication besides sodium-glucose cotransporter 2 inhibitors
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of antidiabetic medication
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of antihypertensive medication besides renin-angiotensin system inhibition
Time Frame: within 6 months
within 6 months
Number of participants with a new prescription of antihypertensive medication
Time Frame: within 6 months
within 6 months
Change in number of antihypertensive medications
Time Frame: within 6 months
within 6 months
Number of participants referred to nephrology outpatient clinics
Time Frame: within 6 months
within 6 months
Number of participants with an assessment of urine albumine to creatine ratio
Time Frame: within 6 months
within 6 months
Number of participants with an assessment of plasma-creatinine.
Time Frame: within 6 months
within 6 months
Number of participants with an assessment of estimated glomerular filtration rate by creatinine
Time Frame: within 6 months
within 6 months
Number of participants with an assessment of hemoglobin A1c
Time Frame: within 6 months
within 6 months
Number of participants with an assessment of lipids
Time Frame: within 6 months
within 6 months
Number of participants recipient of influenza vaccination
Time Frame: within 6 months
within 6 months
Number of participants recipient of COVID-19 vaccination
Time Frame: within 6 months
within 6 months
Total number of visits to general practitioners
Time Frame: within 6 months
within 6 months
Time to first phone contact to a general practice
Time Frame: within 6 months
within 6 months
Time to first visit with a general practitioner
Time Frame: within 6 months
within 6 months
Number of participants with any prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with any prescription of renin-angiotensin system inhibition
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with any prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with a new prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with a new prescription of renin-angiotensin system inhibition
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with a new prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Time from intervention delivery to prescription of renin-angiotensin system inhibition and/or sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Time from randomization to prescription of renin-angiotensin system inhibition
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Time from randomization to prescription of sodium-glucose cotransporter 2 inhibitors
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants who have discontinued renin-angiotensin system inhibition treatment.
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants who have discontinued sodium-glucose cotransporter 2 inhibition treatment.
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Rate of change in estimated glomerular filtration rate
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Rate of change in urine albumine to creatinine ratio
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with any hospitalization
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Total number of all-cause hospitalizations
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
All-cause mortality
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with kidney failure defined as a composite of sustained estimated glomerular filtration rate <15ml/min/1.73m2, dialysis dependence and kidney transplantation
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with kidney failure (alternative definition #1) defined as a composite of sustained estimated glomerular filtration rate <15ml/min/1.73m2, dialysis dependence, kidney transplantation and renal death
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with kidney failure (alternative definition #2) defined as a composite of sustained estimated glomerular filtration rate <15ml/min/1.73m2, dialysis dependence, kidney transplantation, renal death, and cardiovascular death.
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with acute dialysis
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with acute kidney insufficiency
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with incident heart failure, heart failure hospitalization, or cardiovascular death
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with major adverse cardiovascular events defined as a composite of myocardial infarction, stroke, and cardiovascular death.
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with major adverse cardiovascular events (alternative definition) defined as a composite of myocardial infarction, revascularization, stroke, and cardiovascular death.
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years
Number of participants with individual components of the renal/cardiovascular composite outcomes
Time Frame: Within 1, 2, 5 and 10 years
Within 1, 2, 5 and 10 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tor Biering-Sørensen

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tor Biering-Sørensen, MD, MSc, MPH, PhD, Study Principal Investigator Center for Translational Cardiology and Pragmatic Randomized Trials, Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 19, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 19, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 19, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 16, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 7, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 8, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 29, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 26, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • NUDGE-CKD

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data will be collected from Danish administrative health registries, which are subject to Danish legislation and can only be made available to a third party under certain conditions. Please contact the sponsor-investigator in case of any inquiries.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Chronic Kidney Diseases

Clinical Trials on Electronically delivered nudging letter to associated GPs of patients with CKD

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings