METHODS: New adult patients (N = 509) were randomly assigned to primary care physicians at a university medical center. Their use of health care services and associated charges were monitored for 1 year of care. Self-reported health status was measured using the Medical Outcomes Study Short Form-36 (SF-36). We controlled for health status, sociodemographic information, and primary care physician specialty in the statistical analyses.
RESULTS: Women had significantly lower self-reported health status and lower mean education and income than men. Women had a significantly higher mean number of visits to their primary care clinic and diagnostic services than men. Mean charges for primary care, specialty care, emergency treatment, diagnostic services, and annual total charges were all significantly higher for women than men; however, there were no differences for mean hospitalizations or hospital charges. After controlling for health status, sociodemographics, and clinic assignment, women still had higher medical charges for all categories of charges except hospitalizations.
CONCLUSIONS: Women have higher medical care service utilization and higher associated charges than men. Although the appropriateness of these differences was not determined, these findings have implications for health care.
Studies have consistently shown that women use more health care services than men.1-4 Several explanations have been offered. These differences may be associated with reproductive biology and conditions specific to gender,3,5-6 higher rates of morbidity in women than in men,1-4 differences in health perceptions and the reporting of symptoms and illnesses,1-4 or a greater likelihood that women seek help for prevention and illness.1,2,4 Physician referral practice patterns may also partially explain the rates of specialty care and diagnostic testing. Men are referred to specialty care more often than women,7 and hospitalized men are more likely to be referred for invasive cardiac procedures than women.8-9
The authors of some previous studies describing gender differences in the use of health care services have examined large secondary data sets without incorporating important independent variables, such as sociodemographic information or patient health status.3-5 Other researchers have attempted to control for health status by including in the study population only those individuals rating their health as good or excellent.2 Still others have used limited health status measures that have not been tested for reliability and validity.1
Although there have been a number of studies demonstrating distinctive patterns in the use of health care by women, few have reported associated health care expenditure differences. A recent study from Canada (a country with a system of universal health insurance) presented data on the crude annual per capita use of health care resources for men and women in the province of Manitoba.5 Using administrative data from electronic records, the investigators concluded that expenditures for health care were similar for men and women. Unfortunately, data regarding individual health status, sociodemographics, or other possible confounders were unavailable.
The purpose of our study was to examine gender differences in the use of health care services and in the associated charges for 1 year of care. Since any cogent discussion of differential medical visit frequencies and charges requires controlling for sociodemographic and health status patient variables, these factors were incorporated. We chose an instrument widely used in health services research—the Medical Outcomes Study Short Form-36 (SF-36)—to measure self-reported health status. Also, because it has been demonstrated that medical specialty is associated with variations in resource utilization10 and that practice style differences between family physicians and general internists are associated with differential medical charges,11 our analyses also controlled for primary care physician specialty. We hypothesized that even after controlling for these factors women would have more medical care services use and higher charges than men.
Our study population consisted of new patients requesting outpatient appointments at a university medical center. Of the first 956 nonpregnant adults having no preference for a specific physician or specialty, 821 (85%) agreed to participate. These patients were randomly assigned for primary care to either the family practice clinic or the general medicine clinic. Three hundred twelve (38%) of these patients were excluded from the study because they did not keep their appointment or could not be included for scheduling reasons. A total of 509 patients participated in the study, with no differential external health care utilization expected.
Procedures and Measures
We interviewed study participants before the initial visit with their primary care provider to collect sociodemographic data, and we used the SF-36 to determine self-reported health status. The SF-36 contains 8 scales: general health, physical function, physical role, mental role, social function, pain, energy, and mental health. Reliability and validity have been demonstrated for this questionnaire.12,13 Summary measures can be constructed for both physical and mental health status components.14