Emergency Room as a Window for Identifying Undiagnosed Anemia: a Clinical Evaluation.

BACKGROUND: Anemia is a major global health concern with significant clinical consequences, particularly when undiagnosed. The emergency department (ED) provides an important opportunity for opportunistic screening; however, data on undiagnosed anemia in Saudi Arabia are limited. This study aimed to determine the prevalence and hematological characteristics of previously undiagnosed anemia among adult ED visitors in Makkah, Saudi Arabia. METHODS: A cross-sectional study was conducted at the Security Forces Hospital, Makkah, from October through December 2024. Adult patients (≥ 18 years) without a prior diagnosis of anemia were included, while pregnant women and those with trauma or active bleeding were excluded. Demographic and clinical data were retrieved from medical records. Hemoglobin (Hb) levels were analyzed according to World Health Organization (WHO) criteria. Red blood cell indices, including mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH), were used to classify anemia types. Statistical analysis was performed using SPSS; chi-squared and t-tests were applied, with p < 0.05 considered significant. A total of 135 adults were enrolled. RESULTS: The prevalence of previously undiagnosed anemia was 27.4% (n = 37). No significant differences were observed by gender (p = 0.96), age group (p = 0.28), or nationality (p = 1.00). Anemic patients had significantly lower Hb levels than non-anemic individuals (p < 0.001). Among anemic patients, 37.8% had microcytic anemia, 59.5% had normocytic anemia, and 2.7% had macrocytic anemia. A significant association between low MCV and anemia suggested iron deficiency anemia as the predominant cause. Over one-quarter of ED patients had undiagnosed anemia. CONCLUSIONS: Routine screening in EDs could facilitate early detection and timely intervention to reduce complications.