4Luukinen H,Koski K,Kivela SL, et al.Social status, life changes, housing conditions, health, functional abilities and life style as risk factors for recurrent falls among the home-dwelling elderly[].Public Health Nursing.1996
5Cheng,Y.H.,Chi,I.,Boey,W.K.,Ko,F.S.L.,Chou,L.K.‘Self-rated economic condition and the health of elderly persons in Hong Kong’[].Social Science and Medicine.2002