Anemia affects 1.6 billion, or 24.8% of Earth’s population, according to the World Health Organization (WHO). Many blood disorders include anemia among their symptoms, which also varies depending on gender, age, and the region of the world. Complete Blood Counts (CBCs) with hemoglobin measurements are the only approved method for diagnosing anemia. Once a person is diagnosed with anemia, standard care includes routine blood screening to monitor hemoglobin levels. Unfortunately, blood tests are invasive, painful, and relatively costly. Even if you live next door to clinic, getting a blood test can be uncomfortable and inconvenient.

Biomedical engineers at Emory University developed a smartphone app that proved sufficiently accurate to detect anemia non-invasively using patient-sourced photos. The study, published in Nature Communications, found a 97% sensitivity in hemoglobin level estimates by analyzing fingernail bed color and metadata from smartphone photos compared to CBC testing. Rob Mannino, Ph.D., drove the study as part of his Ph.D. graduate work at Emory. Mannino lives with beta-thalassemia, a genetic blood disorder and requires monthly blood transfusions. Mannino’s physicians required CBC testing, an additional tiresome inconvenience to determine transfusion timing and payload. During the work leading up to clinical testing, Mannino took photos of himself before and after transfusions. Wilbur Lam, MD, Ph.D., principal investigator for the study said, “Essentially, he was his own perfect initial test subject with each iteration of the app.” The actual study involved 100 people and the 97% accuracy figure was obtained from the app’s algorithm analyzing one photo from each person. Because the algorithm improves with subsequent photos the results would be even more accurate over time.

The fingernail photo app is not currently approved for diagnosing anemia. More testing and additional studies will be required to validate the app. In the meantime, however, the app has proved sufficient for screening between Mannino’s transfusions and can be a useful, fast, easy, and inexpensive way to screen patients for anemia in the field, in remote settings, and in clinics.