One sign that a patient is not using their medical devices correctly is when you notice an anomaly in the patient generated data. It's possible the patient took a reading that was not accurate but the patient had no idea it was inaccurate and "saved" the measurement anyway. It is always a good practice to follow up with a patient when any anomalies are detected in their patient generated health data. Sometimes these data points will be flagged by the platform if they fall outside of pre-determined thresholds. You can also schedule a video call with a patient, using the in-app video feature, and have them demonstrate how they are taking their vitals to you. The time spent on the call will count towards "interactive time" required to bill on CPT codes 99457 & 99458.