摘要：The charts of a random sample of 496 women, aged 51 and older, in a staff model health maintenance organization (HMO) were retrospectively audited for mammography frequency over an 8-year period. Of the 496 women, 306 (61.7%) had at least one mammogram. For the 422 women who had been members of the HMO for at least 2 years, 196 (46.4%) had mammography within the previous 18 months.
