Abstract Rationale Asthma remains a significant public health challenge in low- and middle-income countries (LMICs), where structural limitations in primary health care (PHC) hinder early diagnosis and effective management. Characterizing real-world patient profiles in PHC is essential to guide strategies that improve disease control and reduce preventable morbidity and mortality. Methods This is a descriptive analysis of baseline data of the CuidAR ongoing cluster-randomized controlled trial conducted across 40 PHC centers spanning Brazil’s five macroregions. Patients aged 6-65 years with a physician-confirmed asthma diagnosis and uncontrolled disease were included. Diagnosis required a compatible clinical history of variable respiratory symptoms and objective evidence of expiratory airflow limitation with a positive bronchodilator response on spirometry. Demographic, clinical, and treatment data were collected using standardized forms and analyzed descriptively. Results Between May 2023 and October 2025, 340 participants were enrolled (mean age 30.8 ± 18.0 years; 65.6% female). Most patients (63.8%) had at least one comorbidity, most frequently allergic rhinitis (39.7%). The mean Asthma Control Test (ACT/cACT) score was 12.5 ± 3.7, with similar values in children (13.2 ± 3.5) and adults (12.2 ± 3.8). Frequent exacerbations were common: 66.3% reported ≥3 episodes in the previous year. Emergency visits were reported by 43.8%, and among those requiring acute care (n = 146), 10.3% were hospitalized. Work or school absenteeism occurred in 61.7%, markedly higher among children/adolescents (84.5%) than adults (49.8%). The most common treatment pattern was SABA use only, affecting 29% of participants (30.9% in children, 28.2% in adults). Mean pre-bronchodilator FEV₁% predicted was 61.4% (±16.8) in children and 55.6% (±15.5) in adults; post-bronchodilator FEV₁% improved to 86.5% (±20.9) and 73.4% (±18.5), respectively. Importantly, the proportion of adults failing to achieve post-bronchodilator FEV₁ normalization was significantly higher compared with participants under 18 years (63.7% vs. 33.3%, respectively; p 0.0001), suggesting more advanced or irreversible airway obstruction in older patients. Conclusions Our results reveal a high burden of uncontrolled asthma within Brazilian PHC. Poor disease control, frequent exacerbations, and heavy reliance on acute care highlight critical gaps in management. The widespread use of SABA monotherapy, contrary to international guideline recommendations, underscores the need for education and system-level interventions. Reduced and less reversible lung function in adults emphasizes the importance of early diagnosis and consistent controller therapy to improve outcomes in LMIC primary care settings. This abstract is funded by: Brazilian Ministry of Health through the Brazilian Unified Health System Institutional Development Programme (PROADI-SUS), and also supported by Aché Laboratórios Farmacêuticos S. A
Pitrez et al. (Fri,) studied this question.