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RESEARCH ARTICLE |
1 Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
2 Department of Health, Behavior, and Society, Johns Hopkins University School of Public Health, Baltimore, Maryland.
3 Department of Public and Community Health, University of Maryland College Park School of Public Health.
Address correspondence to Judith D. Kasper, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, Baltimore, MD 21205. E-mail: jkasper{at}jhsph.edu
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Abstract |
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Methods. We used longitudinal data covering a 30-year period for a cohort of 553 African American women with common life experiences. Interviews were conducted with these women as young mothers, as mothers of adolescents, and in early old age (two thirds aged 60+). We classified women as high, usual, or low functioning by using physical and mental health indicators. We examined both timing and duration of poverty and family stressors.
Results. Initially these women were largely healthy, but health declines were steeper and occurred earlier for those who were low functioning in later life. Persistent poverty was detrimental to functioning at older ages, as was persistent family stress. Women who left poverty early did not differ in later life functioning from women who were never poor.
Discussion. Despite similar earlier life circumstances and health, there was substantial heterogeneity in functioning in early old age. Long-term poverty and family stress were strongly associated with being low functioning. Early poverty and transient family problems did not have lasting health effects, underscoring the plasticity of human development and the importance of interventions that can alter life course trajectories.
Key Words: Poverty • Functional status • Family stress • African American women
THE relationship of race and socioeconomic status (SES) to health disparities and cumulative health disadvantages over the life course has been the focus of a large body of research and several comprehensive reviews (House, 2001
; Zarit, Pearlin, & Hendricks, 2005). Among older people, being Black and being poor are both associated with numerous indicators of poor health, including chronic disease onset (Kington & Smith, 1997) and disability (Schoeni, Martin, Andreski, & Freedman, 2005). Disentangling the effects of race and SES on the health of older individuals has proven difficult, however. Some studies have suggested that socioeconomic factors largely account for the health disadvantages of Blacks (Hayward, Miles, Crimmins, & Yang, 2000). Others have found that race differences persist for some health indicators, even when SES is taken into consideration (Kahn & Fazio, 2005).
One avenue of increasing interest for understanding racial health inequalities at older ages is earlier life experience. A life course perspective offers the opportunity to assess the impact in later life of long-term or cumulative negative (or positive) experiences, as well as the timing of key experiences earlier in life (George, 2002). Recent studies (Kahn & Fazio, 2005; O'Rand, 1996) have provided support for the hypothesis that cumulative disadvantages over the life course are important determinants of health at older ages and contribute to the heterogeneity of health and functioning in older populations. Evidence is growing concerning the biological pathways by which social environment affects health, and in particular the impact of cumulative stress through repeated exposures (Seeman & McEwen, 1996; Seeman, Singer, Ryff, Love, & Levy-Storms, 2002; Uchino, Cacioppo, & Kiecolt-Glaser, 1996).
Socioeconomic disadvantages are of particular import for health over the life course, though the mechanisms involved are complex. Poverty increases exposure to negative physical, psychological, behavioral, and social environments that influence health (Halfon & Hochstein, 2002; Link & Phelan, 2000); limits opportunities for education and achievement (Williams, Yu, Jackson, & Anderson, 1997); restricts access to adequate health care (Felland, Felt-Lisk, & McHugh, 2004; House, 2001; Kasper, 2000); and exposes individuals to numerous stressors that create poor health trajectories over time (Pearlin, Schieman, Fazio, & Meersman, 2005). A robust literature suggesting that stressful social and interpersonal relationships affect health at older ages (Cohen & Syme, 1985; Ensminger & Juon, 2001; House, 2001; House & Williams, 2000; Turner, Wheaton, & Lloyd, 1995) points to the need to examine other sources of stress as well.
Researchers have hypothesized that both the persistence and timing of disadvantages over the life course influence health in later life. Kahn and Pearlin (2006) found that continuous financial hardship across earlier years was more detrimental to the health of older individuals than episodic difficulties. Knowledge concerning how the timing of experiences, such as financial stress, over the life course affects late-life health outcomes is limited (Hayward et al., 2000). A recent study of a British birth cohort found that early childhood SES was associated with functional status in midlife (Guralnik, Butterworth, Wadsworth, & Kuh, 2006), but timing of events may not have uniform effects across population subgroups. Another recent study found that adverse childhood economic conditions were predictive of adult heart attack risk for women but not for men (Hamil-Lukar & O'Rand, 2007).
There are significant challenges to understanding the causal pathways from earlier socioeconomic experiences to later life health disparities. Some relate to data limitations, including short time frames for observation in many studies (e.g., Hayward et al., 2000, who examined a 2-year interval) and reliance on retrospective reports of earlier life experiences such as financial stress (e.g., Kahn & Pearlin, 2006). Sorting out the effects of SES and race on health at older ages is also complicated by findings that suggest possible differences in the impact of SES on health within racial subgroups. Kahn and Fazio (2005) suggested that subjective assessments of financial and other hardships may differ by race. Kahn and Pearlin found that the cumulative effects of financial stress were more detrimental to the health of older Whites than of older African Americans. McDonough, Sacker, and Wiggins (2005) indicated that African Americans who left early poverty were able to close the health gap with African Americans who were never poor, but the same was not true for Whites.
This study contributes to researchers' understanding of the effects on health in later life of the pattern and timing of earlier economic and family stressors by using a unique longitudinal study of a cohort of African American women. Studies of the effects of SES and other stressors over the life course among Black individuals are rare. Examining the dynamics of stressors earlier in life and their effects on later life health among minority women offers the opportunity to observe these relationships without the confounding influence of race. We also examined later life health in terms of both high and low functional status. Evidence of heterogeneity in health at older ages continues to build (Schoeni et al., 2005), as does recognition that research should address factors that contribute to healthy aging as well as disability and decline (e.g., Morrow-Howell, Hinterlong, & Sherraden, 2001). The women in this study cohort have many life experiences in common—at the study's start all were mothers of a child in first grade in the same low-income urban neighborhood in a major metropolitan area. Over a 30-year period, they were interviewed at three points, providing current rather than retrospective views of socioeconomic and other stressors.
We address several related questions in this analysis: (a) How variable is health among these older African American women, who at an earlier stage had a shared neighborhood environment and life experiences in common? (b) Are timing and duration of poverty associated with later life health? (c) What is the impact of poverty and family stressors, cumulatively and at specific points in the life course, on differences in health at older ages? and (d) What is the relative importance of the timing and persistence of poverty and family stressors on later health?
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METHODS |
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). Only 13 families in the Woodlawn neighborhood chose not to participate. At the study's initiation, Woodlawn ranked among the five most impoverished neighborhoods in Chicago, with 3 times as many residents on public assistance per 1,000 population as Chicago as a whole (de Vise, 1967). However, there was socioeconomic diversity in the community, with some census tracts having a high percentage of home ownership and a low percentage of poverty.
Participants (all African American) were interviewed three times over 30 years: in 1967, when their children were in first grade (T1); in 1976, when their children were adolescents (T2); and in 1997, when their children were adults (T3). There were 1,140 (biological) mothers of first graders in the original cohort, ranging in age from 19 to 51. A total of 88% of the original participants were located in 1997; 25% were deceased, but 77% of all survivors were interviewed. (See Ensminger & Juon, 2001, for details regarding longitudinal attrition and characteristics of responders and nonresponders.)
The study sample for this article was women who were interviewed at all three times (n = 553). At T1, these women were 20 to 49 years of age (32% aged 25–29; 34% aged 30–34). At T3, the age range was 51 to 80 (M = 62.2); nearly two thirds (63%) were aged 60 or older, and 29% were aged 55 to 60. Data on household composition indicated that 22% lived alone, 29% lived with one other person, 18% with two other individuals, and 31% with four or more others. Compared to a national sample of Black women in this same age range (drawn from the 1999 National Health Interview Survey), a similar percentage (about one third) were married, but the present study sample was somewhat less educated (27% with at least some college vs 34% nationally). Prevalence of chronic conditions was similar (e.g., 63% hypertension vs 66% nationally; 22% diabetes vs 24% nationally; 11% asthma vs 9% nationally). Although all women initially lived in the same neighborhood, over time many moved. Whether these moves were voluntary or forced by ongoing neighborhood gentrification is not known, nor is whether these moves resulted in improved neighborhood environments. At T3, 82% of surviving women remained in Chicago, 5% lived in the suburbs, and 13% lived outside Chicago.
Measures of Functional Status at T3
There are numerous ways to characterize health and functioning in older people. For this analysis, we followed the approach of Berkman and colleagues (1993), classifying women as high, usual, and low functioning by using both mental and physical health indicators. We used three measurement constructs from the T3 interview: one for physical functioning, one for bodily pain, and one for depressed mood.
Physical functioning and bodily pain were taken from the Short Form-36 (Ware & Sherbourne, 1992), a widely used and well-validated general health status instrument administered in the third interview. The physical functioning measure consists of 10 items that ask about activities persons might do during a typical day and whether "your health now limits you in these activities?" (limited a lot, limited a little, not limited at all). The bodily pain measure is based on two items: "How much bodily pain have you had during the past 4 weeks?" (very severe, severe, moderate, mild, very mild, none) and "During the past 4 weeks, how much did pain interrupt your normal work including both work outside the home and housework?" (extremely, quite a bit, moderately, slightly, not at all). Each Short Form-36 scale ranged from 0 to 100, with higher scores indicating better functioning (for physical functioning, M = 66.8, SD = 29.8; for bodily pain, M = 69.7, SD = 28.1).
The depressed mood construct was based on the sum of scores from 10 items (coded never, almost never, sometimes, fairly often, often) from the Center for Epidemiologic Studies–Depression scale (Radloff, 1977). Scores ranged from 10 to 46, with higher scores indicating a greater degree of depressed mood (M = 18.3, SD = 6.8).
We examined the distribution of scores for women in our study in order to partition the sample into women who were high and low functioning across all three domains. Women with scores in the top 40% on all measures composed 20.1% of the sample; women with scores in the bottom 40% on all three composed 19.8% of the sample. These cutpoints provided equivalent-size groups of high- and low-functioning women (ns = 104 and 109, respectively); we classified the remaining 340 women as usual functioning.
Independent Variables
Demographics
Education and mother's age at birth of first child (<18 or older) were obtained at T1. Marital status and employment status were characterized at each interview. Number of children was lifetime.
Health conditions and self-rated health
Measures were obtained at each interview. At T3, women were asked about a series of health conditions (e.g., Has a doctor told you that you have arthritis?). We used six conditions here: arthritis, diabetes, cancer, hypertension, cardiovascular (heart trouble or heart attack, a blood circulation problem, or "hardening of the arteries"), and asthma or lung disease. Self-rated health (excellent, very good, good, fair, poor) was asked at T3. At T2, women were asked whether in the past 10 years (since the T1 interview) they had been "very healthy, moderately healthy, not too healthy or not at all healthy." A question about feeling sad was asked at both T1 and T2: "How often do you have days when you are sad and blue—very often, fairly often, occasionally, or hardly ever?" At T1, women were asked whether they had an illness or condition that "has lasted a long time or that needs medicine regularly, or that limits activity in any way." They also were asked about health in pregnancy: "Thinking back to your pregnancy with (child in 1st grade), how was your general physical health then—excellent, good, fair or poor?"
Timing and duration of poverty
Income was obtained at each interview and used to classify women as in poverty (100% or below of the federal poverty level based on income and household size at the year of the interview). Timing of poverty was indicated by status at the time of each interview. Duration of poverty used information from all interviews to reflect status over time: not poor (not in poverty at any of the three interviews), early only (poor at T1 and/or T2 but not T3), late only (poor at T3 only), late/episodic (poor at T3 and also at T1 or T2), and persistent (poor at all three interviews).
Family stress
We examined three sources of stress stemming from family problems—drug use, trouble with the law, and high level of household conflict—by using questions asked at T2 and T3.
Drug use in the past year by household members was asked about at T2 (any use of several drugs including marijuana, uppers, cocaine, heroin, or methadone); the question at T3 was "whether there was a problem caused" by using these types of drugs. We determined family member in trouble with law/incarcerated at T2 using questions that asked about trouble with the law or incarceration "that happened to you or a member of your household" since the first interview and, at T3, that "happened to your family" since the T2 interview.
Family conflict was based on several items. We summed scores on the items and classified women with scores in the highest quartile as high conflict. T2 items were the following: have arguments with one another, yell or shout to let off steam, let out hurt and angry feelings, throw things when angry, slam doors when angry. Responses were on a 6-point scale from several times a week to less than every few months (M = 13.3, SD = 5.9, range = 5–30). At T3, two additional items were added (threaten to hit or throw something; kick, hit, or try to hit each other), and item responses were on a 4-point scale from never to often (M = 10.2, SD = 3.4, range = 7–28).
Analysis
We conducted analyses of the relationship of characteristics over the life course to the functional status of older African American women (high, usual, and low functioning at T3) by using multinomial logistic regression (STATA mlogit). A test of the proportional odds assumption (no difference in the coefficients between each pair of outcome groups) indicated that ordinal logistic regression was not appropriate. We used maximum likelihood estimation to calculate logit coefficients (unstandardized logistic regression coefficients) that we then converted to relative risk ratios (the ratios of exponentiated coefficients, commonly interpreted as odds ratios [ORs]). We used ordinal logistic regression when the outcome of interest was dichotomous. All multivariate analyses of later life functional status included age and health at previous interviews as control variables.
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RESULTS |
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Are Timing and Duration of Poverty Associated With Later Life Health?
Overall, this cohort of urban African American women was substantially less well off than other women their age. At T3, 80.7% of women who were low functioning had incomes below 100% of the poverty level. Even among high-functioning women, more than one third were poor. By comparison, only about 13% of all women in the United States aged 60 and older were poor in 1997 (Dalaker & Naifeh, 1998).
Not surprisingly, poverty and poor health at older ages were related (see Table 2). At each interview, women who were high functioning at older ages were less likely to be poor than women who were low functioning. High functioning women also were less likely to be poor both initially (T1) and in later life (T3) than women in the usual-functioning group. About one third of later life high-functioning women were poor at each interview, whereas for usual- and low-functioning women the proportion in poverty increased over time (from 51.5% at T1 to 61.8% at T3 for women who were usual functioning, and from 57.8% at T1 to 80.7% at T3 for women who were low functioning).
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The impact of socioeconomic disadvantage, specifically poverty, on health was a major focus of this analysis, but clearly there are many significant life circumstances closely connected to SES (Pearlin et al., 2005, described these as the "education-occupation-economic chain"). Tables 3 and 4 show marital and employment status, education, number of children, and age at birth of first child as they relate to poverty. Women who were married at any of the three interviews were at substantially reduced risk of being in poverty at that time (OR = 0.14 at T1; OR = 0.12 at T2; OR = 0.34 at T3). Marriage at earlier points was not related to poverty at T3, however. Being employed also reduced the risk of poverty at each interview, and employment at earlier points also was protective against poverty in later life. Marriage appeared somewhat more protective against poverty than employment early on when these women were in their childbearing years, whereas the reverse was true in later life.
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Continuous measures of marital status, employment, and schooling over the 30 years were associated with duration of poverty. Each year of school reduced the likelihood of early poverty by 18% (OR = 0.82), of late poverty by 22% (OR = 0.78), of late/episodic poverty by 33% (OR = 0.67), and of persistent poverty by 42% (OR = 0.58). Each year of marriage and employment also was protective against persistent and late/episodic poverty, although not as dramatically as added years of schooling. For example, each additional year of marriage reduced the likelihood of persistent poverty (relative to not being poor at any time) by 10% (OR = 0.90), each added year of employment reduced the odds by 13% (OR = 0.87), and each added year of schooling reduced the odds by 42%.
What Is the Impact Cumulatively, and at Specific Points in the Life Course, of Poverty and Family Stressors on Functional Differences at Older Ages?
A life course perspective suggests that both the timing of events and how long certain conditions last can affect later outcomes. Table 5 shows the impact on health at older ages of poverty, and of family stress related to drug problems, trouble with the law, and high household conflict, at specific points in time and over an extended period.
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With regard to duration, persistent poverty also was highly detrimental when we adjusted for age and prior health. Women experiencing persistent poverty were 93% less likely to be high versus low functioning in later life relative to women who were never poor (OR = 0.07), 80% less likely to be high versus usual functioning (OR = 0.20), and 66% less likely to be usual versus low functioning (OR = 0.34). Late/episodic poverty was associated with low as opposed to high or usual functioning. It is interesting that women who were only poor early on—at the initial interview or 10 years later—were not at increased risk of being low functioning in later life relative to women who were not poor at any time. Women who were poor in later life only were at marginally greater risk of being low versus high functioning.
Both family drug problems and trouble with the law were more prevalent at T3 than T2. Because these items reflected experiences of all household members, the higher prevalence of these problems at T3 may have been because the children were young adults at this time. Household conflict was at similar levels at the two time points. Almost a quarter of these women reported one or more types of family stress at both T2 and T3; 34.8% reported none at either interview. Despite relatively high prevalence, point-in-time family stress was not related to functional status with one exception: Drug problems at T3 decreased the likelihood of being high or usual as opposed to low functioning. Women who experienced persistent family stress (any of these difficulties at both T2 and T3), however, were 68% less likely to be high as opposed to low functioning (OR = 0.32) compared to women with none of these sources of stress at either time.
What Is the Relative Importance of the Timing and Persistence of Poverty and Family Stressors on Later Functional Status?
Table 6 shows the results of the multivariate analyses that took into account age, earlier health, earlier poverty, and family stressors. The relationship of poverty at T3 to functional status at T3 remained relatively unchanged. Women who were poor were 83% less likely to be high as opposed to low functioning (OR = 0.17) and 53% less likely to be high as opposed to usual functioning (OR = 0.47). Poverty at T1 was associated with usual as opposed to high functioning at T3, but, for the most part, poverty at earlier time points was not related to differences in functional status at T3. Both drug problems and high household conflict at T3 were marginally associated with reduced odds of being high as opposed to low functioning when we controlled for other factors. Drug problems reduced the likelihood of being usual versus low functioning; women reporting high household conflict were less likely to be in the high- as opposed to usual-functioning groups.
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DISCUSSION |
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Although the women in this cohort were largely healthy at the outset of this study, 30 years later as they entered older ages (two thirds were 60 or older at T3), there was substantial heterogeneity in health. Some were in very good health—for example, 27% of the cohort had scores of 90 to 100 on the Short Form-36 Physical Functioning subscale; others were in poor health. The trajectories for high- and low-functioning women are instructive. For women who were low functioning in later life, the proportion indicating poor health climbed steadily over the study period—from 11.9% with a chronic health condition at T1, to 33.9% who were unhealthy at T2, to 83.5% in fair or poor health at T3. By contrast, the proportion of high-functioning women indicating poor health on these measures remained unchanged (at 5.8%) from T1 to T2, increasing to only 11.7% in fair or poor health at T3. This pattern suggests that for women who were low functioning in later life, health declines began much earlier and accumulated over time. Despite commonalities with regard to race and early residence, there were distinct health trajectories in this cohort of women over the 30-year period spanning young adulthood to early old age.
Poverty was highly prevalent in this study cohort. Education, marriage, and employment were key links to the economic advantages/disadvantages experienced by these women during their adult years. Education, employment, and marriage all were protective against poverty at given points. However, each additional year of education had a stronger protective effect against poverty than did each year of marriage or employment. Most dramatically, each added year of schooling conveyed a 42% reduction in the odds of being persistently poor (relative to never being poor). Whether these women avoided poverty, left it early, or experienced persistent poverty was closely tied to contingencies in their wider social environment.
Poverty at each time point was related to functional status at later ages, but there appeared to be important underlying patterns that point-in-time measures did not reveal. Poverty at T3 overrode the effects of poverty at earlier points on later life health when they were considered together. Other studies have also typically found that more recent economic difficulties have a greater health impact than more distant ones (House & Williams, 2000; Kahn & Pearlin, 2006). However, in this subgroup of African American women, at least one third of whom were poor at any of three points over 30 years, those who were always poor and those who were poor in later life but also experienced poverty earlier were in decidedly worse health in later life than their counterparts. These findings are consistent with those from studies of very different population subgroups (Kahn & Fazio, 2005; McDonough et al., 2005) and support the hypothesis that chronic stress associated with cumulative economic disadvantage is a major contributor to poor health at older ages.
Also of interest is that women who were poor only in early to mid-adulthood were no worse off in terms of later life functional status than those who were never poor. A finding that early poverty—if it does not recur or persist—may not have lasting health effects reinforces the plasticity of human development and the value of interventions that can alter life course trajectories. It is intriguing that McDonough and colleagues (2005) found that African Americans who left poverty (as well as younger and better educated people) were able to close the health gap with their African American counterparts who were never poor.
The concept of stress proliferation (Kahn & Pearlin, 2006; Pearlin et al., 2005) posits that stress in certain domains, such as economic well-being, leads to other strains that escalate the health-damaging impact of stress. Experiencing chronic stress of one kind (economic) was associated with another form of chronic stress (family) in this cohort of African American women. Persistent poverty and persistent family stress were significantly correlated (r =.16, p <.001) in this study cohort, and persistent family stress reduced the odds of having high functional status (vs low) even when we considered duration of poverty. The pernicious effects of multiple types of chronic long-term stress on health at older ages seem supported by these findings and are consistent with Lantz, House, Mero, and Williams (2005), who also found that stress (financial, parental) and negative life events were associated with poor health outcomes and contributed to socioeconomic differences in health.
A major strength of this study is that information on poverty, health, and family stressors such as household conflict was from interviews conducted over a 30-year period, as opposed to retrospective recollection of events. Nonetheless, there are several important limitations. One has to do with changes over time in the information obtained. Questions about family stressors, for example, were modified between the T2 and T3 interviews, so although the variables are comparable, they are not identical. In addition, although the 30-year time span covers a major segment of adult life for these women, only three points were sampled across this period. Measures of duration of poverty and family stress based on these may miss important changes in the intervals between interviews. Poverty at all three points is considered "persistent," for example, but it is possible that additional income fluctuations occurred that were not captured. Nonetheless, women who were poor at all three points were likely to have been in poverty for a prolonged period (other data from the study indicated that 50% of these women received welfare for 20+ years).
A life course perspective motivated these analyses, but we could not address many aspects of the life course of these women, including their younger lives. We did not examine other aspects such as health behaviors over the life course. Information on health behaviors in early interviews was limited. Although the link between health behaviors (such as smoking) and morbidity and mortality is unquestionable, Lantz and colleagues (2001) suggested that differences in prevalence of health-risk behaviors is not the major factor accounting for socioeconomic differences in adult physical functioning and health. This is consistent with the "fundamental cause" perspective (e.g., Herd, Goesling, & House, 2007; Link & Phelan, 1995) that points to SES as pervasive in enabling individuals to avoid (or take advantage of) circumstances and behavior that lead to poorer (or better) health, rather than as a proxy for specific behaviors. Neighborhood environment influences on health disparities is another area of growing interest (Morenoff & Lynch, 2004). Although we know that many women relocated over the course of 30 years, we were unable to evaluate whether these moves resulted in better or worse neighborhood environments or what role these moves played in later life health. Functioning at T3 was not associated with whether women lived in the original neighborhood, elsewhere in Chicago, or in the suburbs (or beyond) at T2 or T3, however.
The strong effects of long-term poverty and family stress on health at older ages in a cohort of African American women residing in a low-income urban neighborhood is further evidence of the strength of the connection between social determinants and health. Research has tied health gradients to SES in the population at large (Minkler, Fuller-Thomson, & Guralnik, 2006) and among white-collar workers (Marmot et al., 1991). This study provides evidence of a similar gradient in a cohort of minority women in an economically disadvantaged environment. Of key importance to health in later life, however, was the persistence over the life course of the economic disadvantage and family stressors these women encountered. Those who escaped early poverty or experienced difficult family events that did not last appear to have eluded the negative health trajectories observed in women experiencing persistent stress. Reducing health disparities at older ages must take into account earlier life experiences. Even among individuals who face many disadvantages earlier in life, however, intervening to break patterns of persistent disadvantage and stress may yield health benefits many years later.
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Acknowledgments |
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J. D. Kasper planned the study, supervised the data analysis, and wrote the paper. M. E. Ensminger, K. M. Green, K. E. Fothergill, and H. S. Juon helped plan the study, reviewed draft manuscripts, and contributed to revising the paper. J. Robertson conducted the data analysis. R. J. Thorpe advised on statistical analyses and contributed to revising the paper.
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Received for publication September 5, 2007. Accepted for publication April 1, 2008.
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