The University Record, April 1, 1997

Research Highlights

From time to time the Record will feature research conducted by U-M faculty members.

HMOs haven't met the challenge of reducing growth rate in medical technology

Reductions in health care cost growth achieved by HMOs may not be sustained because many HMOs, like traditional insurers, have not met their toughest challenge---reducing the growth rate in the use of emerging medical technology, according to a study from the School of Public Health, published in the March/April issue of the journal Health Affairs.

The United States has witnessed a three-year decline in the growth of health care costs, but costs have begun rising again in both HMOs and fee-for-service systems. The culprit, according to the researchers, is the increasing demand for and use o f new medical technologies.

In order to determine delivery systems' ability to constrain the use of emerging medical technologies, the researchers examined the effect on utilization rates of a bellwether medical innovation---laparoscopic cholecystectomy (the removal of the g all bladder using minimally invasive endoscopic surgery). Their data, which covered 1989-94, came from six HMOs, fee-for-service systems in Maryland and Connecticut, and Pennsylvania's Medicare system.

"Both before and after the introduction of laparoscopic techniques, HMOs appear to be appropriately conservative in their rates of gall bladder removal. However, we found that while there was some variation among the HMOs, there were no syst ematic differences in the growth of utilization rates for this procedure between the HMOs and the non-HMOs," said Michael Chernew, assistant professor of health management and polic y. "In both systems, when innovative technology substantially reduced the physical burden on the patient, utilization rose."

"Current reductions in health care cost growth associated with HMOs may only reflect transitional savings. Even if HMOs are less expensive than traditional health insurance, if they adopt technologies at these rates, they may not change the underlying rate of health care cost growth," Chernew said.

While the study examined the effects of just one type of surgical innovation on rising health care costs, "the medical system is made up of many discrete procedures that must be controlled. The procedures are like hundreds of small streams t hat, if left unchecked, become a flood," Chernew said. "Ultimate control over health care cost growth will require that HMOs and individuals make tough choices regarding utilization of an ever-growing array of impressive medical services."

Chernew's research colleagues were A. Mark Fendrick, assistant professor of internal medicine and of health management and policy, and Richard A. Hirth, assistant professor of economics and of health management and policy.

Several U-M researchers presented reports on their work at the Population Association of America meeting in Washington, D.C. on March 28.

Popular magazines mislead young women about breast cancer 'epidemic'

Popular magazines are "subtly or blatantly" implying that there is a breast cancer epidemic among young women even though most researchers agree that the approximately 30 percent rise in the age-adjusted incidence of breast cancer in the 1980s is mostly an "artifact of the lead time afforded by mammography screening."

Magazines suggest that the "epidemic" is primarily affecting young women and is related to the lifestyle choices of young, non-traditional women---delayed childbearing or non-childbearing, the use of oral contraceptives, induced abortion , and the use of tobacco and alcohol, according to Paula M. Lantz, assistant professor of health management and policy. Her conclusions are drawn from a study of popular magazines from 19 80-95, including a content analysis of 228 magazine articles published between 1987 and 1995.

Lantz's colleague on the study was Karen M. Booth, the Robert Wood Johnson Scholar in Health Policy Research, University of California-Berkeley School of Public Health.


Study confirms hunch: Alcohol and condoms don't mix

Alcohol use reduces the use of condoms in all types of sexual relationships, according to Kathleen Ford, research scientist in the Department of Epidemiology, School of Public Heal th.

Ford and colleagues interviewed 1,435 African Americans and Hispanics, ages 15-24, in the city of Detroit---population groups that are at high risk for AIDS. Ford examined relationships among three types of sexual partners---married/living togeth er partners; "knew-well partners," where the couple had been in a relationship on average more than half a year; and casual partners, where the couple did not know each other well and had had sex infrequently.

Ford found that, with the exception of the Hispanic women, more than half of the respondents drank. Although the majority of drinkers agreed that alcohol use increased the likelihood of sex, it also decreased the use of condoms among all three gr oups, and particularly among the married/lived with and "knew-well" groups.

"The failure to use condoms due to alcohol is a great health concern, since many of the respondents had been in several different sexual relationships in the past year," Ford says. Ford's research colleague is Anne E. Norris, School of Nursing, Boston College.


More Americans are marrying out of their racial, ethnic groups

A new U-M study provides some reason for optimism about the state of racial relations: more Americans are marrying outside of their own racial group than at any time in the past.

For the study, demographer Reynolds Farley analyzed U.S. Census data on marriage between whites, Blacks, American Indians, and native-born Asians and Hispanics.

"In recent years, the proportion of both men and women from all racial groups who `marry out,' meaning out of their racial group, has increased, and the percent of young Black men who marry white women has increased fairly sharply," says Farley, who is a research scientist at the Population Studies Center and professor of sociology.

Throughout this century, a majority of American Indians have married outside their racial group. In recent decades, a majority of Asian-Americans have also married out, but intermarriage is still much less common for Blacks and whites than for Hi spanics or Asians.

Farley identified a number of factors strongly linked to intermarriage. Place of residence made a large difference, with those living in California or Hawaii much more likely to marry out than those living in the South or Midwest. Educational at tainment also made a large difference, especially for Blacks. "Black men with college degrees were most likely to marry white women," notes Farley.

"It's unclear whether these differences result from differences in racial attitudes and in the willingness to cross racial lines, or whether they are primarily due to demographic differences in the pools of potential marital partners found in various geographical areas and social circles," says Farley, observing that people select marriage partners from the people they meet on a daily basis.

More influential than either geography or education, however, was recent service in the armed forces. The racial integration of the military is breaking down traditional racial dividing lines, Farley points out, since Blacks, whites, Asians and Hispanics who serve in the military are unusually likely to marry outside their own group.