WITH tmp AS (
SELECT
    H.CHECKUP_DATE AS CK_DATE
    ,H.MEMBER_CODE AS CODE
    ,M.LAST_NAME || M.FIRST_NAME AS NAME
    ,H.WEIGHT
    ,LAG(H.WEIGHT,1) OVER (PARTITION BY H.MEMBER_CODE ORDER BY  H.CHECKUP_DATE) AS W1
FROM
    HEALTH_CHECKUP AS H
INNER JOIN
    MEMBER_MST AS M
ON
    H.MEMBER_CODE = M.MEMBER_CODE

)

SELECT
    CK_DATE
    ,CODE
    ,NAME
    ,ROUND(WEIGHT - W1, 1)  AS CHG_WT
FROM
    tmp
WHERE
    W1 IS NOT NULL
    AND
    ABS (ROUND(WEIGHT - W1, 1)) >= 5
ORDER BY 
    WEIGHT - W1 DESC
    ,CODE DESC