Non-Invasive Technologies for Anemia Screening in Remote Settings: A Literature Review ^†

Introduction: Anemia is a hematological condition characterized by reduced hemoglobin levels in the blood, impairing oxygen transport to tissues. Considered a global public health problem, it mainly affects vulnerable populations and regions with limited access to laboratory services. Technological advances allow for improved diagnosis and monitoring through non-invasive methods, reducing the need for laboratory infrastructure and facilitating screening in remote communities. Methodology: A search was conducted in the PubMed, Google Scholar, and ScienceDirect databases. Inclusion criteria encompassed articles published between 2009 and 2025 in English, Portuguese, and Spanish that addressed digital biomarkers or portable devices for anemia screening. Duplicates and studies focused exclusively on laboratory methods were excluded. The initial analysis resulted in the collection of 24 articles. The keywords used were “Anemia,” “Digital Biomarkers,” and “Remote Communities.” The studies were analyzed descriptively, considering the types of technology and their applications. Results: The analysis identified technologies capable of monitoring physical changes related to anemia, such as applications that estimate hemoglobin levels through the coloration of the nail bed and conjunctival images, taking advantage of high vascularization. Compared to conventional methods, these do not require invasive procedures or laboratory infrastructure, facilitating screening in remote areas. However, they present limitations regarding calibration, variations in accuracy among different skin phototypes, and the need for proper user training. Conclusions: Technological advancement expands access to healthcare, but challenges such as validation, standardization, and training still need to be overcome to ensure its effectiveness in remote communities.