Mannino Robert G, Sullivan Julie, Frediani Jennifer K, George Paul, Whitson Jeremy, Tumlin James, Lyon L Andrew, Tyburski Erika A, Lam Wilbur A
Sanguina, Inc., Atlanta, GA 30092.
Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, GA 30322.
Proc Natl Acad Sci U S A. 2025 May 20;122(20):e2424677122. doi: 10.1073/pnas.2424677122. Epub 2025 May 13.
Anemia, characterized by low blood hemoglobin (Hgb) levels, afflicts >2 billion individuals worldwide. Here, we report real-world data generated by a smartphone app that noninvasively screens for anemia using only "fingernail selfies." App data for anemia screening were obtained from >1.4 million uses across the United States enabling geographic mapping of Hgb levels. Of those, 9,061 users also self-reported complete blood count Hgb levels for comparison, resulting in accuracy and performance that match gold standard laboratory testing and a sensitivity and specificity of 89% and 93%, respectively, when using an anemia cutoff of 12.5 g/dL. Geotagged data enabled construction of an "anemia map" of the United States, which demonstrated that Hgb levels correlate with socioeconomic status, and that the app is more likely to be used in counties with higher median income counties, more Black residents, and more primary care physicians. In addition, "personalization" of the app's AI-augmented algorithm empowers self-monitoring of Hgb levels for those already diagnosed with anemia, such as chronic kidney disease (CKD) patients. After personalization, the app's mean absolute error improved from 1.36 to 0.74 g/dL ( = 3.13E-11) and from 0.69 to 0.57 g/dL ( = 0.006) for CKD patients and real-world users with known anemia, respectively. Given its scalability, noninvasiveness, and geotagging capabilities, this app has the potential to enhance public health initiatives by screening an entire population for anemia coupled with geographic mapping. Moreover, personalization of the app enables individuals to serially monitor their Hgb levels instantaneously and remotely.
贫血以血液中血红蛋白（Hgb）水平低为特征，全球有超过20亿人受其困扰。在此，我们报告了一款智能手机应用程序生成的真实世界数据，该应用程序仅通过“指甲自拍照”就能对贫血进行无创筛查。贫血筛查的应用程序数据来自美国各地超过140万次的使用，从而能够对Hgb水平进行地理映射。其中，9061名用户还自行报告了全血细胞计数Hgb水平以供比较，其准确性和性能与金标准实验室检测相当，当使用12.5 g/dL的贫血临界值时，敏感性和特异性分别为89%和93%。带有地理标记的数据使得能够构建美国的“贫血地图”，该地图表明Hgb水平与社会经济地位相关，并且该应用程序在收入中位数较高、黑人居民较多以及初级保健医生较多的县更有可能被使用。此外，该应用程序的人工智能增强算法的“个性化”功能使已被诊断患有贫血的人（如慢性肾脏病（CKD）患者）能够自我监测Hgb水平。个性化之后，该应用程序对于CKD患者和已知患有贫血的真实世界用户的平均绝对误差分别从1.36 g/dL提高到0.74 g/dL（P = 3.13E - 11）和从0.69 g/dL提高到0.57 g/dL（P = 0.006）。鉴于其可扩展性、无创性和地理标记功能，这款应用程序有可能通过对整个人口进行贫血筛查并结合地理映射来加强公共卫生举措。此外，该应用程序的个性化功能使个人能够即时和远程连续监测自己的Hgb水平。
