Incidence rates of falls among Japanese men and women living in Hawaii

Abstract

Japanese people in both Japan and in Hawaii have a lower incidence of hip fractures than white people in Hawaii or on the mainland of the United States. Hip fractures usually occur after a fall, and differing incidence rates of falls might contribute to the observed differences in hip fracture rates. To investigate this possibility, we undertook a prospective study of falls among elderly Japanese men and women living in Hawaii using intensive surveillance methods similar to those used in studies of predominantly white populations. For our Japanese participants, the incidence rates of total falls were 139 per 1000 person-years for men and 276 per 1000 person-years for women. Age-adjusted rate ratios of falls for predominately white populations compared with our Japanese participants ranged from 1.8 to 2.3 for women and from 2.6 to 4.7 for men. The risk of injuries when they did fall, however, was not lower for our Japanese participants than reported for white participants. For our Japanese population, past falls, female gender, and daytime hours were associated with an increased incidence of falls.