Patient-reported VOC events and VOC event duration, as captured by ePRO. (A) Annualized patient self-reported VOC events (median, 8 events per year). (B) Duration of VOC event (sum of the VOC day) reported by patient (mean, 2.7 days). Health care utilization for VOC days based on 346 VOC days (C) and events based on 114 events (D) were categorized as direct (± hospitalization), indirect, or self-treatment. Direct health care utilization resulted in hospitalization from the day of admission to the day of discharge for VOC. Direct health care utilization was a VOC that required an unscheduled “face-to-face” medical contact, including emergency department presentation of the patient (may be <24 hours). Indirect health care utilization was any day in which an unscheduled indirect medical utilization (eg, e-mail, call, or text to medical staff) occurred. Self-treatment VOCs were self-treated requiring no medical utilization. A VOC day is when the patient responds YES to the ePRO question “Did you have a pain crisis in the past 24 hours?” A VOC day was described as a single day when the patient reported having a crisis. The level of health care utilization depicted is the highest level reported for each VOC day or event.