SAN FRANCISCO — Several analyses of data from a longitudinal study of 3,075 elderly African American and white patients have helped identify some of the causes of health disparities between races in older adults, sometimes with surprising results.
Investigators presented their findings in a joint session at the annual meeting of the Gerontological Society of America. The results can inform the clinical care of older African Americans, several speakers said.
For example, depression was strongly associated with widespread bodily pain in African American men, but not in white men. Socioeconomic status played a big role in racial disparities in death rates. Lung function did not seem to influence racial differences seen in physical performance, contrary to expectations.
All of the studies analyzed data from the Health, Aging, and Body Composition (Health ABC) study of 3,075 well-functioning, community-dwelling adults aged 70–79 years at baseline in 1997–1998. The cohort was 42% African American and 48% female and resided in Memphis or Pittsburgh. They were followed with annual clinic visits and interim 6-month phone calls for the first 6 years.
Widespread pain was present in 8% of women regardless of race and in 3% of African American men and 4% of white men after investigations controlled for factors including osteoporosis, arthritis, and depression, reported Gregory H. Hicks, Ph.D., of the University of Delaware, Newark. He analyzed data on 2,423 patients in the Health ABC study who had appropriate records.
African Americans were significantly less likely than whites (28% vs. 53%) to report widespread pain, after accounting for the effects of demographics, socioeconomic status, psychosocial factors, health status, and biological factors.
Depressive symptoms increased the risk of widespread pain ninefold in African Americans, but did not significantly affect risk in whites. Feeling fearful quadrupled the odds for widespread pain in whites, but not for African Americans.
Osteoporosis was associated with a threefold increase in the risk of widespread pain in whites and an eightfold increase in African Americans. Arthritis was associated with a 10-fold increase in the risk of widespread pain in whites and a 13-fold increase in African Americans.
“So from a clinical perspective, it may be that addressing depression may be more important in African Americans, addressing fear may be more important in whites, and addressing osteoporosis is important in both” in order to manage widespread pain, Dr. Hicks said.
Drinking, smoking, and body mass index did not affect rates of widespread pain.
Roland J. Thorpe Jr., Ph.D., and his associates focused a separate analysis on 2,863 Health ABC patients with valid spirometry results in their records. African American patients performed worse on physical performance measures than did whites, but lung function did not explain this difference, said Dr. Thorpe of Johns Hopkins University, Baltimore.
In the African American group, 59% of women and 75% of men found it “very easy” to walk a quarter-mile in the clinic, compared with 75% of women and 82% of men in the white group. Normal gait was slower than 1 m/sec (predictive of mobility limitation) in 42% of women and 25% of men in the African American group and in 16% of women and 8% of men in the white group. A score of less than 2 (representing poor functional status) on a composite of physical activity tests was seen in 52% of women and 33% of men in the African American group, and in 31% of women and 17% of men among whites.
Spirometry results showed normal lung function in 54% of black women and 30% of black men, compared with 35% of white women and 35% of white men.
“Lung function had little bearing on differences in physical functioning” between races, Dr. Thorpe said. “This was contrary to our expectations.” He speculated that other factors that might explain these disparities could include perceived discrimination, residential segregation, or other socioeconomic dimensions.
Annemarie Koster, Ph.D., and her associates at the National Institutes of Health, Bethesda, Md., studied data on 2,937 patients with 8 years of follow-up in the Health ABC study to look at mortality rates and causes. A previous report in 2003 found that age-adjusted all-cause death rates were 30% higher and life expectancy was 2 years shorter in African Americans, compared with whites.
In the current study, half of the African American patients and 25% of whites died during 8 years of follow-up.
After demographic variables were adjusted for, African Americans had a 60% higher risk of mortality. Socioeconomic factors explained about 60% of this difference, Dr. Koster said, and behavioral factors explained another 30% of the difference.