计算每个组合的出现次数

Question

I have 5 conditions (AE) and a bunch of patient ID's. My data set is 2 columns: PatientID, Condition.

There are duplicate PatientID's with every new condition:

PatientID	Condition
456	C
456	E
279	D
123	A
123	C
123	D
187	D
296	E
296	C

I believe there are 31 different potential combinations (order doesn't matter) of those 5 conditions (ie A, AB, ABC, AC, ACDE, etc)

I want to count how many patients in each combination of conditions. So my results for the above would be - CE: 2 D: 2 ACD: 1

I'm more familiar with Excel but if this is better handled in SQL, I can do it there. I think I need to create a table of all the different combinations (any help on that would be appreciated too) and then do a count from there but I'm not sure if that's the best way.

Answer 1

This can also be accomplished using Power Query, available in Windows Excel 2010+ and Excel 365 (Windows or Mac)

To use Power Query

• Select some cell in your Data Table
• Data => Get&Transform => from Table/Range or from within sheet
• When the PQ Editor opens: Home => Advanced Editor
• Make note of the Table Name in Line 2
• Paste the M Code below in place of what you see
• Change the Table name in line 2 back to what was generated originally.
• Read the comments and explore the Applied Steps to understand the algorithm

let

//Change next line to reflect your actual data source
    Source = Excel.CurrentWorkbook(){[Name="Table13"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"PatientID", Int64.Type}, {"Condition", type text}}),

//Group by ID and aggregate a sorted list of each ID's conditions
    #"Grouped Rows" = Table.Group(#"Changed Type", {"PatientID"}, {
        {"Conditions", each Text.Combine(List.Sort([Condition])), type text}
        }),

//Group by Conditions and aggregate with Count
    #"Grouped Rows1" = Table.Group(#"Grouped Rows", {"Conditions"}, {{"Condition Count", each Table.RowCount(_), Int64.Type}})
in
    #"Grouped Rows1"

Answer 2

SQL Server solution

SELECT
    conditions,
    COUNT(*)
FROM (
    SELECT
        patientid,
        STRING_AGG(condition, '') WITHIN GROUP (ORDER BY condition) conditions
    FROM tbl
    GROUP BY patientid
) c
GROUP BY conditions 

Output

conditions	patient_count
ACD	1
CE	2
D	2

db<>fiddle here