The definitions of Principal and All-listed are also provided on the query screens. Principal diagnosis is the condition that is determined during the hospital stay to be the chief reason for causing the hospital admission. All-listed diagnoses are additional conditions that coexist at the time of admission, or that develop during the stay, and which have an effect on the treatment or length of stay in the hospital. Principal procedure is the procedure that was performed for definitive treatment or that was necessary to treat a complication - it is usually that procedure most related to the principal diagnosis. All-listed procedures include all procedures performed during the hospital stay.
Many patients receive multiple procedures during their stay or have multiple diagnoses.
Each procedure and each diagnosis is counted and reported individually. If so, choose LOS to get the average number of days in the hospital. You can choose the mean or median. Mean is the average. Median is the midpoint - half of the cases fall below this amount and half are above this amount.