Objective: To evaluate the association between primary care office systems and mammography utilization by women older than 50 years.
Setting: An independent-practice association health maintenance organization (HMO) in Massachusetts.
Participants: One hundred thirty-two primary care practices, representing 321 physicians and 4378 women with at least 12 months of recent, continuous assignment to a practice participating in the HMO.
Measurements: Practice characteristics and procedures for mammography referral and follow-up were ascertained by interviews of office managers. For each practice, the proportion of women older than 50 years who received a mammogram during their most recent 12-month period of assignment to the practice was calculated.
Main Results: Forty-five percent of eligible women received a mammogram during their most recent year of assignment to an HMO practice. In a regression model, use of one particular urban mammography center, group practice, and low percentage of Medicaid patients in the practice were each associated with 9% to 12% higher mammography utilization; use of flowsheets and the scheduling of mammograms by the patients themselves were associated with 7% to 9% higher utilization. Smaller, nonsignificant increases were associated with the use of reminders to patients (5%) and the presence of only internists on staff (5%). The model accounted for 51% of the variation in mammography utilization among practices.
Conclusions: Mammography utilization among women older than 50 years, in a population in which cost was not a barrier, was related to specific office characteristics. Features of the mammography center, the process for scheduling mammograms, the use of flowsheets to prompt physicians, and the use of reminders to patients are important.