The average length of stay metrics in Mosaic are calculated from all discharge claims submitted by the listed facility during the standard one year reporting period from the time of patient admission to discharge. The metric is calculated in days.
To get the average, we add up the count of days from all eligible stays and divide by the number of stays.
The index event would be a discharge claim submitted during the most recent one year reporting period. The reference period for counting the length of stay would be up to three years. This means that the longest length of stay would be from a patient who was discharged on the last day of the current data set but who was admitted on or before the first day three years back from the end of the current reporting period. This maximum is 1095 days (or 1096 if there is a leap year.) We do not count back past the three year reference period, so any patients who were in care prior to that time will receive a count of the maximum possible days within the reference period.
Although the example below is for home health, the same calculation applies to all Average Length of Stay metrics.
The skinny red rectangles represent the home health stays. As long as the discharge (D/C) occurs during the one year reporting period, we count back up to three years to get a length of stay in days.
The yellow represents our standard reporting period, the period from which we gather our index events; in this case, discharges from home health. This one-year period aligns with the end of our current data set. That is, if the most recent data set end with 2019-Q3, this reporting period ends in the same quarter.
The blue is our counting period - we go back three years from the end of the reporting period to count the full length of stay for patients discharged during the reporting period. To be counted, start of care must be in this period. As you can see from the image, a stay can begin and end within the entire 3 year period.
Length of stay calculations in the Mosaic include only patient stays where the patient has been discharged. As a result, length of stay metrics are shorter than in the Solution than what you will find in other data references. For example: a patient who has been in hospice care for over a year, but not discharged, would not appear in our length of stay metrics even though that would extend the length of stay.