Primary Care Physicians’ Perspectives on Primary Immunodeficiency Diseases (Inborn Errors of Immunity)

INTRODUCTION: Primary immunodeficiency diseases (PIDs), also referred to as inborn errors of immunity, are a heterogeneous group of genetic disorders associated with recurrent infections, immune dysregulation, and increased morbidity and mortality when diagnosis is delayed. Primary care physicians (PCPs) play a critical role in early recognition; however, data on PCPs' knowledge and preparedness regarding PID remain limited. This study aimed to evaluate PCPs' knowledge, clinical approaches, and preparedness regarding PIDs across Türkiye. METHODS: This nationwide, cross-sectional study included 385 PCPs - general practitioners (GPs), family medicine residents (FMRs), and family medicine specialists (FMSs) - working in Family Health Centers in Türkiye. Participants completed a structured online questionnaire assessing sociodemographic characteristics, educational background, clinical experience, self-perceived PID knowledge, and performance on 15 PID-related multiple-choice questions based on international guidelines. Total knowledge scores (range: 0-15) were calculated. Correct response rates for individual items and total scores were compared across professional groups and according to educational and clinical variables. Multivariable logistic regression analyses were performed to identify factors independently associated with higher knowledge scores. RESULTS: The mean total knowledge score was 9.09 ± 2.46 (range 0-15). FMSs demonstrated significantly higher total scores than FMRs and GPs (GPs 8.67 ± 2.47; FMRs 8.82 ± 2.63; FMSs 9.83 ± 2.03; p < 0.001). In multivariable analysis, being an FMS was independently associated with scoring above the mean (OR = 2.02, 95% CI: 1.26-3.23; p = 0.004). Regular participation in general medical educational activities was associated with significantly higher total scores (9.74 ± 2.31 vs. 8.23 ± 2.38; p < 0.001). PCPs who participated in PID-related educational activities within the past 5 years were also associated with higher total scores (9.43 ± 2.58 vs. 8.87 ± 2.47; p = 0.027). PCPs who reported requesting immunoglobulin testing or referring patients with recurrent lower respiratory tract infections achieved significantly higher total scores (9.18 ± 2.43 vs. 7.52 ± 2.42; p = 0.001). PCPs who self-perceived their PID knowledge as moderate or good had substantially higher total knowledge scores compared to those who self-perceived their knowledge as low (low: 8.36 ± 2.55; moderate: 9.41 ± 2.26; good: 10.09 ± 2.50; p < 0.001). CONCLUSION: PID-related knowledge scores among PCPs differed across professional groups, with GPs demonstrating lower scores. Higher knowledge scores were significantly associated with being an FMS and with participation in regular general medical education and past 5-year PID-related education. Strengthening targeted educational strategies, particularly for GPs in primary care settings, may improve early recognition and management of PIDs.