Select statement optimization in sqlite

How to optimize this select statement :

SELECT string,((string like '%re%') + 
               (string like '%es%') + 
               (string like '%se%') + 
               (string like '%ea%') + 
               (string like '%ar%') + 
               (string like '%rc%') + 
               (string like '%ch%')
              ) as hits 
FROM words 
WHERE ((string like '%re%') OR 
       (string like '%es%') OR 
       (string like '%se%') OR 
       (string like '%ea%') OR 
       (string like '%ar%') OR 
       (string like '%rc%') OR 
       (string like '%ch%')
      ) 
ORDER BY hits DESC 
LIMIT 3