Blacks receive significantly fewer surgeries that help senior citizens live better and longer lives compared to whites of the same age, researchers from the Harvard School of Public Health and Dartmouth Medical School said in a study published Thursday in the New England Journal of Medicine and funded by the Robert Wood Johnson Foundation.

The study also found that in many cases, the disparity is getting worse.

''For more than 20 years we have known that black Americans receive a different level of care than whites,'' said Ashish Jha, the report's lead author. ''Despite concerted efforts to address these disparities, this study shows that black seniors continue to receive fewer surgical procedures than whites. On a fundamental level, these differences in care are not acceptable.''

The study examined how often nine types of surgical procedures, ranging from heart bypass surgery to total hip replacement, were performed on some 40 million Medicare enrollees from 1992 to 2001.

In 1992, white patients had higher rates for each of the nine types of procedures. By 2001, not only had the gap failed to substantially decrease in eight of the procedures, it had instead increased sharply in five: back surgeries, valve replacements, hip replacements, knee replacements, and appendix removals.

''When you look at this problem of racial differences over a long period of time, you would hope to see marked reduction in the disparities between the care black and white patients receive,'' said Arnold Epstein, a co-author of the report. ''When we examined these potentially life-saving surgeries, we didn't see any areas of the country where these disparities were eliminated.''

Separately, the State University of New York (SUNY) Downstate Medical Center issued a report Wednesday saying that low-income neighborhoods had suffered a sustained loss of public hospitals in 100 of the nation's largest cities and their suburbs.

Public hospitals serve mainly the poor and those who lack access to private health care, researchers said. More of these facilities were lost between 1996 and 2002 (16 percent in cities and 27 percent in the suburbs) than private for-profit (11 percent in cities and 11 percent in suburbs) and non-profit hospitals (11 percent in cities and 2 percent in the suburbs), said the study, also funded by the Robert Wood Johnson Foundation, a philanthropy specializing in health policy issues.

The closures marked ''a stark contrast to the relatively moderate decline in the number of hospitals nationwide,'' the study said.

''Public hospitals may become an endangered species,'' said Dennis Andrulis, a former SUNY professor now at Drexel University and lead author of the study. ''Not only are public hospitals disappearing from inner cities across the country, they are disappearing from the suburbs as well.''

The report said that urban public hospitals provided less inpatient and emergency care in 2002 than in 1996, with for-profit hospitals now surpassing public hospitals in total admissions for the 100 largest cities. Yet, public hospitals continue to care for more seriously ill patients, as measured by the average length of a hospital stay.

Researchers said the ''most unexpected and potentially troubling finding'' was that poor suburbs are underserved by hospitals compared to well-off suburbs, where hospital resources appear abundant.

''While we all may read more about the impact of public hospital closures on inner cities, the fact is we are also seeing the potential for an impending access crisis in suburbs with high-poverty populations,'' said Andrulis. ''These high-poverty suburbs exist disproportionately in California, Texas, and other areas in the south.''

Among the nation's 100 largest metropolitan areas, poor suburbs made up 44 percent of the total suburban population in 2000 but accounted for only 20 percent of total admissions, inpatient days, and outpatient and emergency visits in 2002.

For the same years, well-off suburbs comprised only 26 percent of the total suburban population yet had more than 40 percent of all suburban hospital admissions, outpatient visits, and emergency department visits.

The report found that, on average, poor suburbs have five times the percentage of Latino residents as well-off suburbs (26.4 percent compared to 5.3 percent) and twice the percentage of population that is foreign-born.

Prior surveys have documented that these groups have the country's highest uninsured rates. ''Lack of health coverage for a significant share of population may be a contributing factor in the much lower levels of use and availability of hospital care in poor suburbs,'' the study said.

By contrast, affluent suburbanites are among the country's best-insured people, it added.

''As the number of public hospitals continues to decline, the concern remains to what extent non-profit and for-profit hospitals are taking or will take on greater responsibilities as safety net providers, and to what degree their focus is on attracting the healthiest of Medicaid patients, leaving the sickest and costliest patients to the care of the remaining public or major safety net hospitals,'' said Andrulis.