Women use primary care more frequently than men [1] and receive more health care services [2], even excluding reproductive services. The fact that men use primary care services less frequently may indicate underuse. Men are less likely than women to have visited a physician within the previous 2 years but are more likely to be hospitalized, excluding conditions related to reproduction [1]. A growing body of literature suggests that higher rates of hospitalization for some conditions may be viewed as sentinel events suggesting inadequate primary care [3]. Although no literature directly addresses sex differences in avoidable hospitalizations, the less frequent use of ambulatory care by men and may be linked to their increased hospitalization rate.

Verbrugge and Steiner [2] found that although ambulatory care was similar for men and women in some ways, women received more care than men for about 30% to 40% of the services studied; an exception was referral to another physician. The higher rate of referral of men to specialist care may be an early step in a sequence that results in greater procedure rates in men. Little information is available on patient preferences for or the appropriateness of these excess referrals.

Verbrugge and Steiner [2] also found that women were more likely than men to receive a definite follow-up appointment; this finding is consistent with those of other studies that show that women are more likely than men to obtain continuity of care [4]. Continuity is important because it has been associated with improved health outcomes in both sexes [5]. Women have a more positive attitude toward health services than do men [6] and are more satisfied with the health care they receive [7]. Satisfaction has been clearly associated with improved outcomes [8]. Women are also much more likely than men to receive preventive care [9], which in turn is associated with improved survival [10]. The improved survival appears to be independent of specific preventive maneuvers, suggesting that other mechanisms connected with more frequent preventive visits may explain the phenomenon.

In their review of studies of physician-patient communication, Hall and colleagues [11] found that female patients were more effective than male patients in having physicians address their needs. Women also perceive themselves to be more involved in their care [12]. Studies suggest that higher levels of patient involvement in care are associated with improved health outcomes [13]. The physician-patient visit may be viewed as a social encounter in which the patient seeks support from the physician. Many articles have documented the fact that women make greater and more effective use of social supports [14]. From this perspective, it is not surprising to find that women use primary care encounters more productively than men.

Although active patient participation has been found to be important in improving primary care, the domain of invasive technical services remains more physician directed. Studies on coronary heart disease show that women receive fewer invasive diagnostic and coronary artery bypass procedures than men [15]. The implicit assumption behind much of the literature on sex differences is that using more invasive diagnostic and surgical procedures is better than using fewer. Overall, however, the application of invasive technology in the United States is high compared with that in other countries; in addition, no research has suggested that incremental benefits result from the greater use of catheterization [16]. Prospective studies of patients from the point of diagnostic procedure do not support the hypothesis that the higher procedure rates in men improve outcomes [17]. Community-based studies examining the prognosis of coronary heart disease by sex show an age-adjusted survival advantage for women, despite lower procedure rates [18].

Women with chest pain are less likely than men to have angiography; however, among persons who do have angiography, normal findings are seen more often in women [19]. Thus, simply increasing the number of procedures done in women will not address problems arising from sex differences in the use of invasive technology.

It is not our intent to address all of the literature on sex biases in health care; sex differences exist in the use of specialized services other than cardiac procedures and in enrollment into clinical trials. Although there may well be limitations in health care delivery that adversely affect women, the debate on this topic has ignored evidence that women may be more effective consumers of health care than men. Attention has focused on the disparities in the application of technology to the detriment of understanding more about the importance of communication and patient preferences. Of particular interest are recent studies of interventions to increase patient involvement in treatment decisions. For example, when information on the risks and benefits of benign prostatic hypertrophy is provided and patient preferences are explicitly elucidated, many men choose not to have surgery [20]. These findings suggest that active involvement in treatment decisions may result in substantially different utilization patterns.

Unfortunately, important information that would shed light on sex differences in various key areas in both the process and outcome of medical care is lacking. For example, research is limited in the promising area of sex differences in physician-patient interactions. More information is also needed on the effect of the patient's sex on the predictive value of coronary artery disease symptoms, the pattern of physician referrals for specialty care, and patient preferences for the use of invasive technology. Ultimately, what is needed is high-quality research that explores the possibility of a direct link between the manner in which women use primary care and their lower procedure rates and improved cardiac prognosis.

We consider the view that women passively receive an inferior form of the health care that is optimally delivered to men to be both demeaning to women and misguided. Merely providing more invasive technological services to women is an oversimplified response to sex differences in health care utilization and will do little to promote equity of access or optimal health outcomes. Instead, we believe that the active approach that women take in obtaining their care should be encouraged and that approaches to helping men become more effective consumers of health care need to be developed.

Dr. Clancy: Division of Primary Care, Agency for Health Policy and Research, EOC 502, 2101 East Jefferson Street, Rockville, MD 20852-4908.

@copy; 1995 American College of Physicians