在charls数据库中变量ea001_w3_1_3_：Med. Ins. from Prev. Wave Correct? New Cooperative Medical Insurance (Hezuo Yili）以及变量ea001_w3_2_3_：Still has Med. Ins. from Prev. Wave? New Cooperative Medical Insurance (Hezuo Yi）是什么意思？第一个变量是说明参加新农合，第二个是还在参加新农合的意思吗？求指导！万分感谢！！！