Thank you for your question regarding CMS871v3, Hospital Harm – Severe Hyperglycemia. For this measure, hospital days are not defined as midnight-to-midnight. Rather, they are defined as full 24-hour periods that start at the time of admission to the hospital (including emergency department and observation), excluding the last period before inpatient discharge from the hospital if that period is less than 24 hours. Additionally, when evaluating for days with a hyperglycemic event, the first 24-hour period after admission to the hospital is not evaluated to account for potentially poor glucose control outside of the hospital setting or that preceded the start of hospital care. Because the first 24-hour period after admission to the hospital is not evaluated, if a patient’s entire encounter is less than 24 hours, they would not fall into the Numerator, because glucose results from the patient’s encounter would not be evaluated. To illustrate this concept, we have attached a table displaying a patient scenario, using the patient’s admission and discharge dates and times to show how the measure determines eligible hospital days.