Excel Video 68 shows how to nest functions, or put a function inside another function, in Excel. VLOOKUP is a powerful function, but it is even more powerful if you can combine other Excel functions inside VLOOKUP. In Video 68, we have a table of patients and ICD-9 codes and a table that categorizes the ICD-9 codes into groups. Rather than list each ICD-9 code in the grouping table, it’s much more efficient to group the diagnosis codes by the first three digits of the code.
We’ll use the LEFT function to capture the first three digits in the patient list, then combine LEFT with VLOOKUP to only look for the first three digits of the diagnosis code in the grouping table. By only looking for the first three digits, our grouping table is much smaller and more efficient than having to list every potential diagnosis code in the grouping table. This trick will only become more efficient with ICD-10.
Try using other Excel functions, like RIGHT to get the last digit of an E&M code, to make VLOOKUP more powerful for you. Stay tuned. Next time we’ll use VLOOKUP inside VLOOKUP to lookup two things at once.
