Vital Signs Measurement Using a Smartphone Camera and a Designated Application at the Hospital-at-Home Setting. A Clinical Validation Study

Background. Hospital-at-Home (HaH) has become a viable alternative to in-hospital stay, worldwide. Reliable vital signs measurement in this setting is of utmost importance. The validity of vital signs acquisition through the use of cellular applications has not been previously explored. Methods. This was a prospective, controlled clinical trial in the HaH setting. We compared vital signs of HaH patients, sequentially appreciated by a cellular application measurements (CAM) and by conventional measurement (CM) performed by a nurse, in the patients’ homes. Results. Vital signs were compared for 91HaH patients (median age 65 years (IQR 22), with 47.3% females), 77.3% patients were classified as bright/white skin tone. CAM heart rate (HR) was median 75 bpm (IQR 21) vs. 77 bpm (IQR 20) by CM, (p = 0.053); CAM of systolic blood pressure (SBP) was 124 mmHg (IQR 24.5) vs. 116 mmHg (IQR 20) by CM, (p = 0.018); CAM of diastolic blood pressure (DBP) was 75.0 mmHg (IQR 16) vs. 76.0 mmHg (IQR 15) by CM, (p = 0.599); CAM respiratory rate (RR) was 18 breaths/min (IQR 6) vs. 16 breaths/min (IQR 5.75) by CM, (p = 0.003); CAM oxygen blood saturation was 97.0% (IQR 3) vs. 98.0% (IQR 1) by CM, (p = 0.002). Agreement between methods measured by Interrater reliability (ICC) was moderate for HR (ICC = 0.71), lower for RR (ICC = 0.37) and poor for SBP measurement (ICC = 0.21). ICC values for DBP and SpO ₂ were − 0.03 and 0.06 respectively. In a multivariable analysis, darker skin categories were associated with substantial bias in diastolic blood pressure estimation. Conclusions. Our findings indicate that CAM technology can estimate some physiological parameters, particularly heart rate, but other measurements show limited agreement with standard monitoring. While promising for remote care such as HaH when conventional measurement is unavailable, broader validation, algorithm improvement, and rigorous clinical evaluation are essential before routine, widespread clinical use.