Longitudinal Validation of the RADAR Score in Primary Care: Prognostic Value for Exacerbations and Short-term Changes...

The longitudinal validity of the RADAR score for predicting short-term risk in primary care remains unestablished. We aimed to evaluate its prognostic performance for adverse events and to describe short-term changes in control status and patient-reported health status in a real-world prospective cohort.

In this multicenter study, 706 primary care patients with COPD receiving maintenance triple therapy were assessed at baseline and after a median follow-up of 91 days. We analyzed the association between baseline RADAR control status (≥4 vs <4) and 3-month outcomes (all-cause mortality, severe exacerbations, moderate exacerbations, and composite events). We also described 3-month changes in RADAR score (ΔRADAR) and COPD Assessment Test score (ΔCAT).

Baseline poor control (RADAR ≥4) was strongly associated with severe exacerbations (16.2% vs 4.9%; OR, 3.75) and composite events (33.8% vs 22.9%; OR, 1.72). No significant difference was observed for moderate exacerbations (18.0% vs 18.9%). However, when modeled as a frequency count, each 1-point increase in RADAR score was associated with a 21% higher rate of moderate exacerbations (incidence rate ratio, 1.21; 95% CI, 1.15-1.27; P<.001). Patients with RADAR ≥4 exhibited a high-risk profile characterized by worse airflow limitation, active smoking, higher symptom burden, and poorer adherence. Over 3 months, significant changes were observed in the distributions of both ΔCAT and ΔRADAR when analyzed by clinical phenotype and risk level.

The RADAR score effectively predicts short-term clinical risk in primary care and provides a practical tool for monitoring COPD and guiding clinical decision-making. It demonstrates significant prognostic value for identifying patients at high short-term risk of severe exacerbations and serves as an initial risk stratification tool to identify individuals requiring further assessment. The observed short-term changes highlight the dynamic nature of COPD control.