A Nationwide Factorial Randomized Trial of Electronic Nudges to Patients With Chronic Kidney Disease and Their General Practices for Increasing Guideline-Directed Medical Therapy: The NUDGE-CKD Trial

BACKGROUND: Many individuals with chronic kidney disease (CKD) face a considerable but modifiable risk of cardiovascular and renal outcomes because of suboptimal implementation of guideline-directed medical therapy (GDMT). We investigated whether electronic letter-based nudges delivered to individuals with CKD and their general practices could increase GDMT uptake. METHODS: This was a nationwide 2×2 factorial implementation trial with randomization at the patient and general practice level and analyzed at the patient level. All Danish adults with a hospital diagnosis of CKD and access to the official Danish electronic letter system were individually randomized at a 1:1 ratio to usual care (no letter) or to receive an electronic letter-based nudge on GDMT for CKD; general practitioners of individuals with CKD were independently randomized (1:1) to receive no letter or an electronic informational letter on GDMT. Intervention letters were delivered on August 19, 2024. Data were collected through the Danish administrative health registries. The primary end point was a filled prescription of a renin-angiotensin system inhibitor or a sodium-glucose cotransporter 2 inhibitor within 6 months of intervention delivery. RESULTS: A total of 22 617 patients with CKD were randomized to the patient-level intervention, with 11 223 allocated to receive the electronic nudge letter and 11 394 to usual care. Separately, 1540 general practices caring for 28 069 patients with CKD were randomized to the provider-level intervention, with 774 practices (13 959 patients) allocated to the intervention and 766 practices (14 110 patients) to usual care. During follow-up, 7303 (65.1%) allocated to the patient-directed nudge had filled a prescription for a renin-angiotensin system inhibitor or sodium-glucose cotransporter 2 inhibitor compared with 7505 (65.9%) in usual care (difference, -0.79 percentage points [95% CI, -2.03 to 0.45]; P=0.21). Among patients of practices receiving the provider-directed letter, 8921 (63.9%) filled a prescription for a renin-angiotensin system inhibitor or sodium-glucose cotransporter 2 inhibitor compared with 9086 (64.4%) in the usual care group (difference, -0.49 percentage points [95% CI, -1.64 to 0.66]; P=0.41). No interaction was observed between the two interventions (P_interaction=0.85). CONCLUSIONS: In this nationwide pragmatic, 2×2 factorial implementation trial, electronic letter-based nudges on GDMT delivered to patients with CKD or their general practice did not increase the uptake of a renin-angiotensin system inhibitor or sodium-glucose cotransporter 2 inhibitor as compared with usual care. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06300086.