Scripting

I have the following SQL that I am using to get the Patching Percentages based upon OS and it is working just fine. However, I would like to add a column to it that would Call out the Patch Severity of Critical patches that have not been patched yet based upon the NOTPATCHED column in the same query. I can get to a point where I am displaying the report, but it is SUM'ing up ALL Critical patches regardless of the detected Patch Status. Is this possible to do in the same report? See below:

WORKING SQL BELOW - BUT WOULD LIKE TO UPDATE WITH ABOVE:

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SELECT
M.OS_NAME as OS,
 SUM(MS.DETECT_STATUS='NOTPATCHED') AS NOT_PATCHED,
 SUM(MS.DETECT_STATUS='PATCHED') AS PATCHED,
 
 ((SUM(MS.DETECT_STATUS='PATCHED'))*100)/(SUM(MS.DETECT_STATUS='PATCHED')+SUM(MS.DETECT_STATUS='NOTPATCHED')) AS PERCENT_PATCHED  
FROM
 MACHINE M
  LEFT JOIN PATCH_MACHINE_STATUS MS
  ON (M.ID = MS.MACHINE_ID)
 LEFT JOIN KBSYS.PATCH P
  ON (P.ID = MS.PATCH_ID)      
WHERE
  P.IS_SUPERCEDED != 1
GROUP BY
  M.OS_NAME
ORDER BY
NOT_PATCHED desc

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This SQL highlighted below is one that i have tried and resulted in the output of all critical patches regardless of Detected Patch Status:

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SELECT
M.OS_NAME as OS,
 SUM(MS.DETECT_STATUS='NOTPATCHED') AS NOT_PATCHED,

 SUM(P.SEVERITY='CRITICAL') UNPATCHED_CRITICALS,
 SUM(MS.DETECT_STATUS='PATCHED') AS PATCHED,
 
 ((SUM(MS.DETECT_STATUS='PATCHED'))*100)/(SUM(MS.DETECT_STATUS='PATCHED')+SUM(MS.DETECT_STATUS='NOTPATCHED')) AS PERCENT_PATCHED  
FROM
 MACHINE M
  LEFT JOIN PATCH_MACHINE_STATUS MS
  ON (M.ID = MS.MACHINE_ID)
 LEFT JOIN KBSYS.PATCH P
  ON (P.ID = MS.PATCH_ID)      
WHERE
  P.IS_SUPERCEDED != 1
GROUP BY
  M.OS_NAME
ORDER BY
NOT_PATCHED desc