1 つの列の類似性に基づいて、他のすべての列の変更を確認します

基本的に必要なデータは、列に複数の値を持つエンティティの数です。

これは列単位で最も簡単に計算できます:

select sum(case when NumFirstNames <> 1 then 1 else 0 end) as DifferentFirstNames,
       sum(case when NumLastNames <> 1 then 1 else 0 end) as DifferentLastNames,
       sum(case when NumSSN <> 1 then 1 else 0 end) as DifferentSSN,
       sum(case when NumPhone <> 1 then 1 else 0 end) as DifferentPhone       
from (select EncounterId, count(*) as Num,
             count(distinct FirstName) as NumFirstNames,
             count(distinct LastName) as NumLastNames,
             count(distinct SSN) as NumSSN,
             count(distinct Phone) as NumPhone
      from table t
      group by EncounterId
     ) e;
  

 結果は好きなようにフォーマットできます。